[PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[Steven Price]

This series adds support for running protected VMs using KVM under the
Arm Confidential Compute Architecture (CCA), including the firmware
support needed to communicate with the Realm Management Monitor (RMM).

For v15 the series was split into a 6-patch generic firmware/RMM series
and a 37-patch KVM series. The two parts are combined again for v16, as
requested to allow the complete stack to be tested by Sashiko as a
single series.

The first six patches add the generic firmware layer for talking to the
RMM, as specified by version 2.0-bet2 of the RMM specification[0]. They
provide the RMI definitions and wrappers, discover and configure the
RMM, implement Stateful RMI Operations (SROs), and ensure that the RMM
has GPT entries for host memory. The remaining patches add the KVM
support needed to create, populate and run Realm VMs.

Note that RMM v2.0 Beta 3 specification should be published soon. The
changes introduced in that are minor and I expect this series to be
largely compatible with the new spec.

The RMM v2.0 specification introduces SROs, which allow the RMM to
complete an operation over several SMC calls while requesting or
returning memory to the host. This allows interrupts to be handled in
the middle of an operation and lets the RMM dynamically allocate memory
for internal tracking purposes. For example, RMI_REC_CREATE no longer
needs auxiliary granules to be provided up front, and can instead
request memory during the operation.

The main changes since v15 are:

 * Recombine the firmware/RMM and KVM portions into one series. The
   Realm-specific RMI wrappers remain separate from the generic
   firmware wrappers, in a new KVM patch.

 * Rewrite Realm entry and exit handling to fit into the generic KVM
   run loop. Work which cannot be performed in the entry path is now
   completed through KVM requests, and MMIO, PSCI, RIPAS changes and
   host calls are adapted to the new flow.

 * Rewrite Realm timer support to use KVM's IRQ-ops infrastructure and
   software resampling.

 * Improve SRO cancellation and error handling. Ensure a cancelled
   operation isn't treated as successful, wrapper return values can carry
   negative Linux errors as well as RMI return values, and those errors
   are propagated through the KVM users.

 * Check that the RMM supports the host page size before configuring it,
   and exclude firmware-reserved NOMAP memory when creating GPT entries.

 * Expand the KVM_ARM_RMI_POPULATE documentation to make clear that Arm
   CCA cannot preserve memory contents during an in-place
   shared-to-private conversion.

 * Allocate Realm parameters only while creating the Realm descriptor.

 * Document the encoding of the arm64 VM types and require
   ICH_HCR_EL2.TDIR before advertising or creating Realm VMs.

This series is based on the guest_memfd in-place conversion v9 tree[1],
which is itself based on kvm-x86/next. It is also available as a git
repository:

https://gitlab.arm.com/linux-arm/linux-cca cca-host/v16

Work in progress changes for kvmtool are available from the git
repository below:

https://gitlab.arm.com/linux-arm/kvmtool-cca cca/v13

The TF-RMM branch used for testing this series is available here:

https://git.trustedfirmware.org/TF-RMM/tf-rmm.git topics/rmm-v2.0-poc_3

There is a kvm-unit-test branch updated to support the attestation used
in RMM v2.0 available here:

https://gitlab.arm.com/linux-arm/kvm-unit-tests-cca cca/v4

[0] https://developer.arm.com/documentation/den0137/2-0bet2/
One bet2 change, which moves metadata out of the individual address
range descriptors, has intentionally not been implemented because that
part of the specification is expected to be reverted.

[1] https://github.com/googleprodkernel/linux-cc/commits/guest_memfd-inplace-conversion-v9

Jean-Philippe Brucker (6):
  KVM: arm64: CCA: Propagate breakpoint and watchpoint counts to
    userspace
  KVM: arm64: CCA: Set breakpoint parameters through SET_ONE_REG
  KVM: arm64: CCA: Propagate max SVE vector length from the RMM
  KVM: arm64: CCA: Configure max SVE vector length for a Realm
  KVM: arm64: CCA: Provide register list for unfinalized RECs
  KVM: arm64: CCA: Provide an accurate register list

Joey Gouly (2):
  KVM: arm64: CCA: Allow userspace to inject aborts
  KVM: arm64: CCA: Support RSI_HOST_CALL

Steven Price (34):
  firmware: arm_rmm: Add SMC definitions for calling the RMM
  firmware: arm_rmm: Add wrappers for direct RMI calls
  firmware: arm_rmm: Check for RMI support at init
  firmware: arm_rmm: Configure the RMM with the host's page size
  firmware: arm_rmm: Add support for SRO
  firmware: arm_rmm: Ensure the RMM has GPT entries for memory
  arm64: mm: Handle Granule Protection Faults (GPFs)
  KVM: arm64: Avoid including linux/kvm_host.h in kvm_pgtable.h
  KVM: arm64: CCA: Add wrappers for realm related RMIs
  KVM: arm64: CCA: Check for RMI support at KVM init
  KVM: arm64: CCA: Check for LPA2 support
  KVM: arm64: CCA: Define the user ABI
  KVM: arm64: CCA: Add basic infrastructure for creating a realm
  KVM: arm64: CCA: Allow passing the machine type in KVM creation
  KVM: arm64: CCA: Tear down RTTs
  KVM: arm64: CCA: Allocate and free RECs to match vCPUs
  KVM: arm64: CCA: Support the VGIC in realms
  KVM: arm64: CCA: Support timers in realm RECs
  KVM: arm64: CCA: Handle realm enter/exit
  KVM: arm64: CCA: Handle RMI_EXIT_RIPAS_CHANGE
  KVM: arm64: CCA: Handle realm MMIO emulation
  KVM: arm64: Expose support for private memory
  KVM: arm64: CCA: Create the realm descriptor
  KVM: arm64: CCA: Activate realms on first vCPU run
  KVM: arm64: CCA: Allow populating initial contents
  KVM: arm64: CCA: Set RIPAS of initial memslots
  KVM: arm64: CCA: Support runtime faulting of memory
  KVM: arm64: CCA: Handle realm vCPU load
  KVM: arm64: CCA: Validate register access for Realm VMs
  KVM: arm64: CCA: Handle Realm PSCI requests
  KVM: arm64: WARN on injected undef exceptions
  KVM: arm64: CCA: Prevent Device mappings for realms
  KVM: arm64: CCA: Require ICH_HCR_EL2.TDIR for realms
  KVM: arm64: CCA: Enable realms to be created

Suzuki K Poulose (3):
  KVM: arm64: Include kvm_emulate.h in kvm/arm_psci.h
  KVM: arm64: CCA: Don't expose unsupported capabilities for realm
    guests
  KVM: arm64: CCA: Allow checking SVE on VM instance

 Documentation/virt/kvm/api.rst       |   70 +-
 arch/arm64/Kconfig                   |    1 +
 arch/arm64/include/asm/kvm_asm.h     |    2 +
 arch/arm64/include/asm/kvm_emulate.h |   37 +
 arch/arm64/include/asm/kvm_host.h    |   12 +-
 arch/arm64/include/asm/kvm_pgtable.h |    6 +-
 arch/arm64/include/asm/kvm_pkvm.h    |    2 +-
 arch/arm64/include/asm/kvm_rmi.h     |  139 +++
 arch/arm64/include/asm/rmi_cmds.h    |  465 ++++++++
 arch/arm64/include/asm/virt.h        |    1 +
 arch/arm64/kernel/cpufeature.c       |    1 +
 arch/arm64/kvm/Kconfig               |    2 +
 arch/arm64/kvm/Makefile              |    2 +-
 arch/arm64/kvm/arch_timer.c          |   34 +-
 arch/arm64/kvm/arm.c                 |  139 ++-
 arch/arm64/kvm/guest.c               |   93 +-
 arch/arm64/kvm/handle_exit.c         |   14 +
 arch/arm64/kvm/hyp/pgtable.c         |    1 +
 arch/arm64/kvm/hypercalls.c          |    4 +-
 arch/arm64/kvm/inject_fault.c        |    5 +-
 arch/arm64/kvm/mmio.c                |   16 +-
 arch/arm64/kvm/mmu.c                 |  144 ++-
 arch/arm64/kvm/reset.c               |   13 +-
 arch/arm64/kvm/rmi-exit.c            |  178 +++
 arch/arm64/kvm/rmi.c                 | 1561 ++++++++++++++++++++++++++
 arch/arm64/kvm/sys_regs.c            |   47 +-
 arch/arm64/kvm/vgic/vgic-init.c      |    2 +-
 arch/arm64/mm/fault.c                |   28 +-
 drivers/firmware/Kconfig             |    1 +
 drivers/firmware/Makefile            |    1 +
 drivers/firmware/arm_rmm/Kconfig     |   26 +
 drivers/firmware/arm_rmm/Makefile    |    2 +
 drivers/firmware/arm_rmm/rmi.c       |  776 +++++++++++++
 include/kvm/arm_psci.h               |    2 +
 include/linux/arm-rmi-cmds.h         |  201 ++++
 include/linux/arm-smccc-rmi.h        |  493 ++++++++
 include/uapi/linux/kvm.h             |   20 +-
 37 files changed, 4446 insertions(+), 95 deletions(-)
 create mode 100644 arch/arm64/include/asm/kvm_rmi.h
 create mode 100644 arch/arm64/include/asm/rmi_cmds.h
 create mode 100644 arch/arm64/kvm/rmi-exit.c
 create mode 100644 arch/arm64/kvm/rmi.c
 create mode 100644 drivers/firmware/arm_rmm/Kconfig
 create mode 100644 drivers/firmware/arm_rmm/Makefile
 create mode 100644 drivers/firmware/arm_rmm/rmi.c
 create mode 100644 include/linux/arm-rmi-cmds.h
 create mode 100644 include/linux/arm-smccc-rmi.h

-- 
2.43.0

[PATCH v16 01/45] firmware: arm_rmm: Add SMC definitions for calling the RMM

[Steven Price]

The RMM (Realm Management Monitor) provides functionality that can be
accessed by SMC calls from the host.

The SMC definitions are based on DEN0137[1] version 2.0-bet2

[1] https://developer.arm.com/documentation/den0137/2-0bet2/

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Dropped unused symbols REC_MAX_GIC_NUM_LRS and RMI_PERMITTED_GICV3_HCR_BITS.
 * Output is now (partially) generated from the spec source.
Changes since v14:
 * Updated to RMM spec v2.0-bet2 but without the changes to move
   metadata out of individual address range descriptors as this is
   expected to be reverted in a future spec release.
Changes since v13:
 * Updated to RMM spec v2.0-bet1
Changes since v12:
 * Updated to RMM spec v2.0-bet0
Changes since v9:
 * Corrected size of 'ripas_value' in struct rec_exit. The spec states
   this is an 8-bit type with padding afterwards (rather than a u64).
Changes since v8:
 * Added RMI_PERMITTED_GICV3_HCR_BITS to define which bits the RMM
   permits to be modified.
Changes since v6:
 * Renamed REC_ENTER_xxx defines to include 'FLAG' to make it obvious
   these are flag values.
Changes since v5:
 * Sorted the SMC #defines by value.
 * Renamed SMI_RxI_CALL to SMI_RMI_CALL since the macro is only used for
   RMI calls.
 * Renamed REC_GIC_NUM_LRS to REC_MAX_GIC_NUM_LRS since the actual
   number of available list registers could be lower.
 * Provided a define for the reserved fields of FeatureRegister0.
 * Fix inconsistent names for padding fields.
Changes since v4:
 * Update to point to final released RMM spec.
 * Minor rearrangements.
Changes since v3:
 * Update to match RMM spec v1.0-rel0-rc1.
Changes since v2:
 * Fix specification link.
 * Rename rec_entry->rec_enter to match spec.
 * Fix size of pmu_ovf_status to match spec.
---
 include/linux/arm-smccc-rmi.h | 493 ++++++++++++++++++++++++++++++++++
 1 file changed, 493 insertions(+)
 create mode 100644 include/linux/arm-smccc-rmi.h

diff --git a/include/linux/arm-smccc-rmi.h b/include/linux/arm-smccc-rmi.h
new file mode 100644
index 000000000000..3dad7bb62ba1
--- /dev/null
+++ b/include/linux/arm-smccc-rmi.h
@@ -0,0 +1,493 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ *
+ * The values and structures in this file are from the Realm Management Monitor
+ * specification (DEN0137) version 2.0-bet2:
+ * https://developer.arm.com/documentation/den0137/2-0bet2/
+ */
+
+#ifndef __LINUX_ARM_SMCCC_RMI_H_
+#define __LINUX_ARM_SMCCC_RMI_H_
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/build_bug.h>
+#include <linux/sizes.h>
+
+#include <asm/page.h>
+
+#define SMC_RMI_CALL(func)				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
+			   ARM_SMCCC_SMC_64,		\
+			   ARM_SMCCC_OWNER_STANDARD,	\
+			   (func))
+
+#define SMC_RMI_VERSION				SMC_RMI_CALL(0x0150)
+
+#define SMC_RMI_RTT_DATA_MAP_INIT		SMC_RMI_CALL(0x0153)
+
+#define SMC_RMI_REALM_ACTIVATE			SMC_RMI_CALL(0x0157)
+#define SMC_RMI_REALM_CREATE			SMC_RMI_CALL(0x0158)
+#define SMC_RMI_REALM_DESTROY			SMC_RMI_CALL(0x0159)
+#define SMC_RMI_REC_CREATE			SMC_RMI_CALL(0x015a)
+#define SMC_RMI_REC_DESTROY			SMC_RMI_CALL(0x015b)
+#define SMC_RMI_REC_ENTER			SMC_RMI_CALL(0x015c)
+#define SMC_RMI_RTT_CREATE			SMC_RMI_CALL(0x015d)
+#define SMC_RMI_RTT_DESTROY			SMC_RMI_CALL(0x015e)
+
+#define SMC_RMI_RTT_READ_ENTRY			SMC_RMI_CALL(0x0161)
+
+#define SMC_RMI_RTT_DEV_VALIDATE		SMC_RMI_CALL(0x0163)
+#define SMC_RMI_PSCI_COMPLETE			SMC_RMI_CALL(0x0164)
+#define SMC_RMI_FEATURES			SMC_RMI_CALL(0x0165)
+#define SMC_RMI_RTT_FOLD			SMC_RMI_CALL(0x0166)
+
+#define SMC_RMI_RTT_INIT_RIPAS			SMC_RMI_CALL(0x0168)
+#define SMC_RMI_RTT_SET_RIPAS			SMC_RMI_CALL(0x0169)
+#define SMC_RMI_VSMMU_CREATE			SMC_RMI_CALL(0x016a)
+#define SMC_RMI_VSMMU_DESTROY			SMC_RMI_CALL(0x016b)
+
+#define SMC_RMI_RMM_CONFIG_SET			SMC_RMI_CALL(0x016e)
+#define SMC_RMI_PSMMU_IRQ_NOTIFY		SMC_RMI_CALL(0x016f)
+#define SMC_RMI_ATTEST_PLAT_TOKEN_REFRESH	SMC_RMI_CALL(0x0170)
+
+#define SMC_RMI_PDEV_ABORT			SMC_RMI_CALL(0x0174)
+#define SMC_RMI_PDEV_COMMUNICATE		SMC_RMI_CALL(0x0175)
+#define SMC_RMI_PDEV_CREATE			SMC_RMI_CALL(0x0176)
+#define SMC_RMI_PDEV_DESTROY			SMC_RMI_CALL(0x0177)
+#define SMC_RMI_PDEV_GET_STATE			SMC_RMI_CALL(0x0178)
+
+#define SMC_RMI_PDEV_STREAM_KEY_REFRESH		SMC_RMI_CALL(0x017a)
+#define SMC_RMI_PDEV_SET_PUBKEY			SMC_RMI_CALL(0x017b)
+#define SMC_RMI_PDEV_STOP			SMC_RMI_CALL(0x017c)
+#define SMC_RMI_RTT_AUX_CREATE			SMC_RMI_CALL(0x017d)
+#define SMC_RMI_RTT_AUX_DESTROY			SMC_RMI_CALL(0x017e)
+#define SMC_RMI_RTT_AUX_FOLD			SMC_RMI_CALL(0x017f)
+
+#define SMC_RMI_VDEV_ABORT			SMC_RMI_CALL(0x0185)
+#define SMC_RMI_VDEV_COMMUNICATE		SMC_RMI_CALL(0x0186)
+#define SMC_RMI_VDEV_CREATE			SMC_RMI_CALL(0x0187)
+#define SMC_RMI_VDEV_DESTROY			SMC_RMI_CALL(0x0188)
+#define SMC_RMI_VDEV_GET_STATE			SMC_RMI_CALL(0x0189)
+#define SMC_RMI_VDEV_UNLOCK			SMC_RMI_CALL(0x018a)
+#define SMC_RMI_RTT_SET_S2AP			SMC_RMI_CALL(0x018b)
+
+#define SMC_RMI_VDEV_GET_INTERFACE_REPORT	SMC_RMI_CALL(0x01d0)
+#define SMC_RMI_VDEV_GET_MEASUREMENTS		SMC_RMI_CALL(0x01d1)
+#define SMC_RMI_VDEV_LOCK			SMC_RMI_CALL(0x01d2)
+#define SMC_RMI_VDEV_START			SMC_RMI_CALL(0x01d3)
+#define SMC_RMI_VDEV_P2P_BIND			SMC_RMI_CALL(0x01d4)
+#define SMC_RMI_VDEV_P2P_UNBIND			SMC_RMI_CALL(0x01d5)
+#define SMC_RMI_VSMMU_EVENT_HANDLE		SMC_RMI_CALL(0x01d6)
+#define SMC_RMI_PSMMU_ACTIVATE			SMC_RMI_CALL(0x01d7)
+#define SMC_RMI_PSMMU_DEACTIVATE		SMC_RMI_CALL(0x01d8)
+
+#define SMC_RMI_PSMMU_ST_L2_CREATE		SMC_RMI_CALL(0x01db)
+#define SMC_RMI_PSMMU_ST_L2_DESTROY		SMC_RMI_CALL(0x01dc)
+#define SMC_RMI_DPT_L0_CREATE			SMC_RMI_CALL(0x01dd)
+#define SMC_RMI_DPT_L0_DESTROY			SMC_RMI_CALL(0x01de)
+#define SMC_RMI_DPT_L1_CREATE			SMC_RMI_CALL(0x01df)
+#define SMC_RMI_DPT_L1_DESTROY			SMC_RMI_CALL(0x01e0)
+#define SMC_RMI_GRANULE_TRACKING_GET		SMC_RMI_CALL(0x01e1)
+
+#define SMC_RMI_GRANULE_TRACKING_SET		SMC_RMI_CALL(0x01e3)
+#define SMC_RMI_CMEM_ADD_PDEV			SMC_RMI_CALL(0x01e4)
+#define SMC_RMI_CMEM_CREATE			SMC_RMI_CALL(0x01e5)
+#define SMC_RMI_CMEM_DESTROY			SMC_RMI_CALL(0x01e6)
+#define SMC_RMI_CMEM_POPULATE			SMC_RMI_CALL(0x01e7)
+#define SMC_RMI_CMEM_REMOVE_PDEV		SMC_RMI_CALL(0x01e8)
+#define SMC_RMI_CMEM_START			SMC_RMI_CALL(0x01e9)
+#define SMC_RMI_CMEM_STOP			SMC_RMI_CALL(0x01ea)
+#define SMC_RMI_CMEM_UNPOPULATE			SMC_RMI_CALL(0x01eb)
+#define SMC_RMI_RMM_CONFIG_GET			SMC_RMI_CALL(0x01ec)
+#define SMC_RMI_PDEV_MEC_REFRESH		SMC_RMI_CALL(0x01ed)
+#define SMC_RMI_RMM_STATE_GET			SMC_RMI_CALL(0x01ee)
+
+#define SMC_RMI_PSMMU_EVENT_CONSUME		SMC_RMI_CALL(0x01f0)
+#define SMC_RMI_GRANULE_RANGE_DELEGATE		SMC_RMI_CALL(0x01f1)
+#define SMC_RMI_GRANULE_RANGE_UNDELEGATE	SMC_RMI_CALL(0x01f2)
+#define SMC_RMI_GPT_L1_CREATE			SMC_RMI_CALL(0x01f3)
+#define SMC_RMI_GPT_L1_DESTROY			SMC_RMI_CALL(0x01f4)
+#define SMC_RMI_RTT_DATA_MAP			SMC_RMI_CALL(0x01f5)
+#define SMC_RMI_RTT_DATA_UNMAP			SMC_RMI_CALL(0x01f6)
+#define SMC_RMI_RTT_DEV_MAP			SMC_RMI_CALL(0x01f7)
+#define SMC_RMI_RTT_DEV_UNMAP			SMC_RMI_CALL(0x01f8)
+#define SMC_RMI_RTT_ARCH_DEV_MAP		SMC_RMI_CALL(0x01f9)
+#define SMC_RMI_RTT_ARCH_DEV_UNMAP		SMC_RMI_CALL(0x01fa)
+#define SMC_RMI_RTT_UNPROT_MAP			SMC_RMI_CALL(0x01fb)
+#define SMC_RMI_RTT_UNPROT_UNMAP		SMC_RMI_CALL(0x01fc)
+#define SMC_RMI_RTT_AUX_PROT_MAP		SMC_RMI_CALL(0x01fd)
+#define SMC_RMI_RTT_AUX_PROT_UNMAP		SMC_RMI_CALL(0x01fe)
+#define SMC_RMI_RTT_AUX_UNPROT_MAP		SMC_RMI_CALL(0x01ff)
+#define SMC_RMI_RTT_AUX_UNPROT_UNMAP		SMC_RMI_CALL(0x0200)
+#define SMC_RMI_REALM_TERMINATE			SMC_RMI_CALL(0x0201)
+#define SMC_RMI_RMM_ACTIVATE			SMC_RMI_CALL(0x0202)
+#define SMC_RMI_OP_CONTINUE			SMC_RMI_CALL(0x0203)
+#define SMC_RMI_PDEV_STREAM_CONNECT		SMC_RMI_CALL(0x0204)
+#define SMC_RMI_PDEV_STREAM_DISCONNECT		SMC_RMI_CALL(0x0205)
+#define SMC_RMI_PDEV_STREAM_COMPLETE		SMC_RMI_CALL(0x0206)
+#define SMC_RMI_PDEV_STREAM_KEY_PURGE		SMC_RMI_CALL(0x0207)
+#define SMC_RMI_OP_MEM_DONATE			SMC_RMI_CALL(0x0208)
+#define SMC_RMI_OP_MEM_RECLAIM			SMC_RMI_CALL(0x0209)
+#define SMC_RMI_OP_CANCEL			SMC_RMI_CALL(0x020a)
+#define SMC_RMI_VSMMU_FEATURES			SMC_RMI_CALL(0x020b)
+#define SMC_RMI_VSMMU_CMD_GET			SMC_RMI_CALL(0x020c)
+#define SMC_RMI_VSMMU_CMD_COMPLETE		SMC_RMI_CALL(0x020d)
+#define SMC_RMI_PSMMU_INFO			SMC_RMI_CALL(0x020e)
+
+#define RMI_ABI_MAJOR_VERSION	2
+#define RMI_ABI_MINOR_VERSION	0
+
+#define RMI_ABI_VERSION_GET_MAJOR(version) ((version) >> 16)
+#define RMI_ABI_VERSION_GET_MINOR(version) ((version) & 0xFFFF)
+#define RMI_ABI_VERSION(major, minor)      (((major) << 16) | (minor))
+
+#define RMI_RETURN_STATUS_MASK		(0xFFUL)
+#define RMI_RETURN_INDEX_MASK		(0xFFUL << 8)
+#define RMI_RETURN_MEMREQ_MASK		(0x3UL << 8)
+#define RMI_RETURN_CAN_CANCEL_MASK	(0x1UL << 10)
+
+#define RMI_RETURN_STATUS(ret)		FIELD_GET(RMI_RETURN_STATUS_MASK, ret)
+#define RMI_RETURN_INDEX(ret)		FIELD_GET(RMI_RETURN_INDEX_MASK, ret)
+#define RMI_RETURN_MEMREQ(ret)		FIELD_GET(RMI_RETURN_MEMREQ_MASK, ret)
+#define RMI_RETURN_CAN_CANCEL(ret)	FIELD_GET(RMI_RETURN_CAN_CANCEL_MASK, ret)
+
+#define RMI_SUCCESS			0
+#define RMI_ERROR_INPUT			1
+#define RMI_ERROR_REALM			2
+#define RMI_ERROR_REC			3
+#define RMI_ERROR_RTT			4
+#define RMI_ERROR_NOT_SUPPORTED		5
+#define RMI_ERROR_DEVICE		6
+#define RMI_ERROR_RTT_AUX		7
+#define RMI_ERROR_PSMMU_ST		8
+#define RMI_ERROR_DPT			9
+#define RMI_BUSY			10
+#define RMI_ERROR_GLOBAL		11
+#define RMI_ERROR_TRACKING		12
+#define RMI_INCOMPLETE			13
+#define RMI_BLOCKED			14
+#define RMI_ERROR_GPT			15
+#define RMI_ERROR_GRANULE		16
+
+#define RMI_CONTINUE_KEEP_GOING		0
+#define RMI_CONTINUE_STOP		1
+
+#define RMI_OP_MEM_REQ_NONE		0
+#define RMI_OP_MEM_REQ_DONATE		1
+#define RMI_OP_MEM_REQ_RECLAIM		2
+
+#define RMI_DONATE_SIZE_MASK		3UL
+#define RMI_DONATE_COUNT_MASK		GENMASK(15, 2)
+#define RMI_DONATE_CONTIG_MASK		BIT(16)
+#define RMI_DONATE_STATE_MASK		BIT(17)
+
+#define RMI_DONATE_SIZE(req)		FIELD_GET(RMI_DONATE_SIZE_MASK, req)
+#define RMI_DONATE_COUNT(req)		FIELD_GET(RMI_DONATE_COUNT_MASK, req)
+#define RMI_DONATE_CONTIG(req)		FIELD_GET(RMI_DONATE_CONTIG_MASK, req)
+#define RMI_DONATE_STATE(req)		FIELD_GET(RMI_DONATE_STATE_MASK, req)
+
+#define RMI_OP_MEM_DELEGATED		0
+#define RMI_OP_MEM_UNDELEGATED		1
+
+#define RMI_ADDR_TYPE_NONE		0
+#define RMI_ADDR_TYPE_SINGLE		1
+#define RMI_ADDR_TYPE_LIST		2
+
+#define RMI_ADDR_RANGE_SIZE_MASK	GENMASK(1, 0)
+#define RMI_ADDR_RANGE_COUNT_MASK	GENMASK(PAGE_SHIFT - 1, 2)
+#define RMI_ADDR_RANGE_ADDR_MASK	(PAGE_MASK & GENMASK(51, 0))
+#define RMI_ADDR_RANGE_STATE_MASK	BIT(63)
+
+#define RMI_ADDR_RANGE_SIZE(ar)		(FIELD_GET(RMI_ADDR_RANGE_SIZE_MASK, \
+						   (ar)))
+#define RMI_ADDR_RANGE_COUNT(ar)	(FIELD_GET(RMI_ADDR_RANGE_COUNT_MASK, \
+						   (ar)))
+#define RMI_ADDR_RANGE_ADDR(ar)		((ar) & RMI_ADDR_RANGE_ADDR_MASK)
+#define RMI_ADDR_RANGE_STATE(ar)	(FIELD_GET(RMI_ADDR_RANGE_STATE_MASK, \
+						   (ar)))
+
+enum rmi_ripas {
+	RMI_EMPTY = 0,
+	RMI_RAM = 1,
+	RMI_DESTROYED = 2,
+	RMI_DEV = 3,
+};
+
+#define RMI_NO_MEASURE_CONTENT	0
+#define RMI_MEASURE_CONTENT	1
+
+#define RMI_FEATURE_REGISTER_0_S2SZ		GENMASK(7, 0)
+#define RMI_FEATURE_REGISTER_0_LPA2		BIT(8)
+#define RMI_FEATURE_REGISTER_0_SVE		BIT(9)
+#define RMI_FEATURE_REGISTER_0_SVE_VL		GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_0_NUM_BPS		GENMASK(19, 14)
+#define RMI_FEATURE_REGISTER_0_NUM_WPS		GENMASK(25, 20)
+#define RMI_FEATURE_REGISTER_0_PMU		BIT(26)
+#define RMI_FEATURE_REGISTER_0_PMU_NUM_CTRS	GENMASK(31, 27)
+
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_4KB	BIT(0)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_16KB	BIT(1)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_64KB	BIT(2)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_256	BIT(3)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_384	BIT(4)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_512	BIT(5)
+#define RMI_FEATURE_REGISTER_1_MAX_RECS_ORDER	GENMASK(9, 6)
+#define RMI_FEATURE_REGISTER_1_L0GPTSZ		GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_1_PPS		GENMASK(16, 14)
+
+#define RMI_FEATURE_REGISTER_2_DA		BIT(0)
+#define RMI_FEATURE_REGISTER_2_DA_COH		BIT(1)
+#define RMI_FEATURE_REGISTER_2_VSMMU		BIT(2)
+#define RMI_FEATURE_REGISTER_2_ATS		BIT(3)
+#define RMI_FEATURE_REGISTER_2_MAX_VDEVS_ORDER	GENMASK(7, 4)
+#define RMI_FEATURE_REGISTER_2_VDEV_KROU	BIT(8)
+#define RMI_FEATURE_REGISTER_2_NON_TEE_STREAM	BIT(9)
+#define RMI_FEATURE_REGISTER_2_P2P		BIT(10)
+#define RMI_FEATURE_REGISTER_2_CMEM_CXL		BIT(11)
+#define RMI_FEATURE_REGISTER_2_MAX_CMEM		GENMASK(19, 12)
+#define RMI_FEATURE_REGISTER_2_CMEM_TSE_REQ	BIT(20)
+
+#define RMI_FEATURE_REGISTER_3_MAX_NUM_AUX_PLANES	GENMASK(3, 0)
+#define RMI_FEATURE_REGISTER_3_RTT_PLANE		GENMASK(5, 4)
+#define RMI_FEATURE_REGISTER_3_RTT_S2AP_INDIRECT	BIT(6)
+
+#define RMI_FEATURE_REGISTER_4_MEC_COUNT		GENMASK(63, 0)
+
+#define RMI_MEM_CATEGORY_CONVENTIONAL		0
+#define RMI_MEM_CATEGORY_DEV_NCOH		1
+#define RMI_MEM_CATEGORY_DEV_COH		2
+
+#define RMI_TRACKING_RESERVED			0
+#define RMI_TRACKING_NONE			1
+#define RMI_TRACKING_FINE			2
+#define RMI_TRACKING_COARSE			3
+
+#define RMI_GRANULE_SIZE_4KB	0
+#define RMI_GRANULE_SIZE_16KB	1
+#define RMI_GRANULE_SIZE_64KB	2
+
+/*
+ * Note many of these fields are smaller than u64 but all fields have u64
+ * alignment, so use u64 to ensure correct alignment.
+ */
+struct rmm_config {
+	union { /* 0x0 */
+		struct {
+			u64 tracking_region_size;
+			u64 rmi_granule_size;
+		};
+		u8 sizer[SZ_4K];
+	};
+};
+
+static_assert(sizeof(struct rmm_config) == SZ_4K);
+
+#define RMI_REALM_PARAM_FLAG_LPA2		BIT(0)
+#define RMI_REALM_PARAM_FLAG_SVE		BIT(1)
+#define RMI_REALM_PARAM_FLAG_PMU		BIT(2)
+#define RMI_REALM_PARAM_FLAG_DA			BIT(3)
+#define RMI_REALM_PARAM_FLAG_LFA_POLICY		GENMASK(6, 5)
+#define RMI_REALM_PARAM_FLAG_MEC_POLICY		GENMASK(8, 7)
+
+#define RMI_HASH_SHA_256			0
+#define RMI_HASH_SHA_512			1
+#define RMI_HASH_SHA_384			2
+
+struct realm_params {
+	union { /* 0x0 */
+		struct {
+			u64 flags0;
+			u64 s2sz;
+			u64 sve_vl;
+			u64 num_bps;
+			u64 num_wps;
+			u64 pmu_num_ctrs;
+			u64 hash_algo;
+			u64 num_aux_planes;
+		};
+		u8 padding0[0x400];
+	};
+	union { /* 0x400 */
+		struct {
+			u8 rpv[64];
+			u64 ats_plane;
+		};
+		u8 padding1[0x400];
+	};
+	union { /* 0x800 */
+		struct {
+			u64 padding2;
+			u64 rtt_base;
+			s64 rtt_level_start;
+			u64 rtt_num_start;
+			u64 flags1;
+		};
+		u8 padding3[0x700];
+	};
+	union { /* 0xf00 */
+		struct {
+			u8 padding4[0x80];
+			u64 aux_rtt_base[3];
+		};
+		u8 padding5[0x100];
+	};
+};
+
+static_assert(sizeof(struct realm_params) == SZ_4K);
+
+/*
+ * The number of GPRs (starting from X0) that are
+ * configured by the host when a REC is created.
+ */
+#define REC_CREATE_NR_GPRS		8
+
+#define REC_PARAMS_FLAG_RUNNABLE	BIT(0)
+
+struct rec_params {
+	union { /* 0x0 */
+		u64 flags;
+		u8 padding0[0x100];
+	};
+	union { /* 0x100 */
+		u64 mpidr;
+		u8 padding1[0x100];
+	};
+	union { /* 0x200 */
+		u64 pc;
+		u8 padding2[0x100];
+	};
+	union { /* 0x300 */
+		u64 gprs[REC_CREATE_NR_GPRS];
+		u8 padding3[0xd00];
+	};
+};
+
+static_assert(sizeof(struct rec_params) == SZ_4K);
+
+#define REC_ENTER_FLAG_EMULATED_MMIO	BIT(0)
+#define REC_ENTER_FLAG_INJECT_SEA	BIT(1)
+#define REC_ENTER_FLAG_TRAP_WFI		BIT(2)
+#define REC_ENTER_FLAG_TRAP_WFE		BIT(3)
+#define REC_ENTER_FLAG_RIPAS_RESPONSE	BIT(4)
+#define REC_ENTER_FLAG_S2AP_RESPONSE	BIT(5)
+#define REC_ENTER_FLAG_DEV_MEM_RESPONSE	BIT(6)
+#define REC_ENTER_FLAG_FORCE_P0		BIT(7)
+
+#define REC_RUN_GPRS			31
+
+struct rec_enter {
+	union { /* 0x000 */
+		u64 flags;
+		u8 padding0[0x200];
+	};
+	union { /* 0x200 */
+		u64 gprs[REC_RUN_GPRS];
+		u8 padding1[0x600];
+	};
+};
+
+static_assert(sizeof(struct rec_enter) == SZ_2K);
+
+#define RMI_EXIT_SYNC			0x00
+#define RMI_EXIT_IRQ			0x01
+#define RMI_EXIT_FIQ			0x02
+#define RMI_EXIT_PSCI			0x03
+#define RMI_EXIT_RIPAS_CHANGE		0x04
+#define RMI_EXIT_HOST_CALL		0x05
+#define RMI_EXIT_SERROR			0x06
+#define RMI_EXIT_S2AP_CHANGE		0x07
+#define RMI_EXIT_VDEV_VALIDATE_MAPPING	0x08
+#define RMI_EXIT_VSMMU_COMMAND		0x0a
+#define RMI_EXIT_VDEV_P2P_BINDING	0x0b
+
+struct rec_exit {
+	union { /* 0x000 */
+		u8 exit_reason;
+		u8 padding0[0x100];
+	};
+	union { /* 0x100 */
+		struct {
+			u64 esr;
+			u64 far;
+			u64 hpfar;
+			u64 rtt_tree;
+		};
+		u8 padding1[0x100];
+	};
+	union { /* 0x200 */
+		u64 gprs[REC_RUN_GPRS];
+		u8 padding2[0x100];
+	};
+	union { /* 0x300 */
+		u8 padding3[0x100];
+	};
+	union { /* 0x400 */
+		struct {
+			u64 cntp_ctl;
+			u64 cntp_cval;
+			u64 cntv_ctl;
+			u64 cntv_cval;
+		};
+		u8 padding4[0x100];
+	};
+	union { /* 0x500 */
+		struct {
+			u64 ripas_base;
+			u64 ripas_top;
+			u8 ripas_value;
+			u8 padding5[0xf];
+			u64 s2ap_base;
+			u64 s2ap_top;
+			u64 vdev_id_1;
+			u64 vdev_id_2;
+			u64 dev_mem_base;
+			u64 dev_mem_top;
+			u64 dev_mem_pa;
+		};
+		u8 padding6[0x100];
+	};
+	union { /* 0x600 */
+		struct {
+			u16 imm;
+			u8 padding7[0x6];
+			u64 plane;
+		};
+		u8 padding8[0x100];
+	};
+	union { /* 0x700 */
+		struct {
+			u8 pmu_ovf_status;
+			u8 padding9[0xf];
+			u64 vsmmu;
+		};
+		u8 padding10[0x100];
+	};
+};
+
+static_assert(sizeof(struct rec_exit) == SZ_2K);
+
+struct rec_run {
+	struct rec_enter enter;
+	struct rec_exit exit;
+};
+
+static_assert(sizeof(struct rec_run) == SZ_4K);
+
+/* RMI_RTT_UNPROT_MAP_FLAGS definitions */
+#define RMI_RTT_UNPROT_MAP_FLAGS_OADDR_TYPE	GENMASK(1, 0)
+#define RMI_RTT_UNPROT_MAP_FLAGS_LIST_COUNT	GENMASK(15, 2)
+#define RMI_RTT_UNPROT_MAP_FLAGS_MEMATTR	GENMASK(18, 16)
+#define RMI_RTT_UNPROT_MAP_FLAGS_S2AP		GENMASK(22, 19)
+
+/* RMI_RTT_PROT_MAP_FLAGS definitions */
+#define RMI_RTT_PROT_MAP_FLAGS_OADDR_TYPE	GENMASK(1, 0)
+#define RMI_RTT_PROT_MAP_FLAGS_LIST_COUNT	GENMASK(15, 2)
+
+/* S2AP Direct Encodings, used in RMI_RTT_UNPROT_MAP_FLAGS_S2AP */
+#define RMI_S2AP_DIRECT_WRITE			BIT(0)
+#define RMI_S2AP_DIRECT_READ			BIT(1)
+
+#endif /* __LINUX_ARM_SMCCC_RMI_H_ */
-- 
2.43.0

[PATCH v16 02/45] firmware: arm_rmm: Add wrappers for direct RMI calls

[Steven Price]

The wrappers make the call sites easier to read and deal with the
boilerplate of handling the error codes from the RMM.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes from v15:
 * Split out wrappers for realms to a separate commit.
 * Wrappers that have output arguments now only write the output when
   the command completes successfully.
Changes from v14:
 * Update to RMM v2.0-bet2 spec.
 * Move SRO related wrappers to a later patch due to dependencies.
 * Common wrappers are split into include/linux/arm-rmi-cmds.h.
Changes from v13:
 * Update to RMM v2.0-bet1 spec including some SRO support (there still
   some FIXMEs where SRO support is incomplete).
Changes from v12:
 * Update to RMM v2.0 specification
Changes from v8:
 * Switch from arm_smccc_1_2_smc() to arm_smccc_1_2_invoke() in
   rmi_rtt_read_entry() for consistency.
Changes from v7:
 * Minor renaming of parameters and updated comments
Changes from v5:
 * Further improve comments
Changes from v4:
 * Improve comments
Changes from v2:
 * Make output arguments optional.
 * Mask RIPAS value rmi_rtt_read_entry()
 * Drop unused rmi_rtt_get_phys()
---
 include/linux/arm-rmi-cmds.h | 83 ++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 include/linux/arm-rmi-cmds.h

diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
new file mode 100644
index 000000000000..5ee94da96e4a
--- /dev/null
+++ b/include/linux/arm-rmi-cmds.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2026 ARM Ltd.
+ */
+
+#ifndef __LINUX_ARM_RMI_CMDS_H_
+#define __LINUX_ARM_RMI_CMDS_H_
+
+#include <linux/arm-smccc-rmi.h>
+#include <linux/bug.h>
+#include <linux/types.h>
+
+#include <asm/page.h>
+
+/**
+ * rmi_rmm_config_set() - Configure the RMM
+ * @cfg_ptr: PA of a struct rmm_config
+ *
+ * Sets configuration options on the RMM.
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_rmm_config_set(unsigned long cfg_ptr)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_RMM_CONFIG_SET, cfg_ptr, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_granule_tracking_get() - Get configuration of a Granule tracking region
+ * @start: Base PA of the tracking region
+ * @end: End of the PA region
+ * @out_category: Memory category
+ * @out_state: Tracking region state
+ * @out_top: Top of the memory region
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_granule_tracking_get(unsigned long start,
+					   unsigned long end,
+					   unsigned long *out_category,
+					   unsigned long *out_state,
+					   unsigned long *out_top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_GRANULE_TRACKING_GET, start, end, &res);
+
+	if (res.a0 == RMI_SUCCESS) {
+		if (out_category)
+			*out_category = res.a1;
+		if (out_state)
+			*out_state = res.a2;
+		if (out_top)
+			*out_top = res.a3;
+	}
+
+	return res.a0;
+}
+
+/**
+ * rmi_features() - Read feature register
+ * @index: Feature register index
+ * @out: Feature register value is written to this pointer
+ *
+ * Return: RMI return code
+ */
+static inline int rmi_features(unsigned long index, unsigned long *out)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_FEATURES, index, &res);
+
+	if (res.a0 == RMI_SUCCESS && out)
+		*out = res.a1;
+
+	return res.a0;
+}
+
+#endif
-- 
2.43.0

[PATCH v16 03/45] firmware: arm_rmm: Check for RMI support at init

[Steven Price]

Query the RMI version number and check if it is a compatible version.
The first two feature registers are read and exposed for future code to
use.

Signed-off-by: Steven Price <steven.price@arm.com>
---
v16:
 * Update Kconfig text to include PCIe TDISP.
 * Export rmi_feat_reg() here rather than in a later commit.
v15:
 * The code is moved again, this time into the 'firmware' directory.
v14:
 * This moves the basic RMI setup into the 'kernel' directory. This is
   because RMI will be used for some features outside of KVM so should
   be available even if KVM isn't compiled in.
---
 arch/arm64/Kconfig                |   1 +
 arch/arm64/kernel/cpufeature.c    |   1 +
 drivers/firmware/Kconfig          |   1 +
 drivers/firmware/Makefile         |   1 +
 drivers/firmware/arm_rmm/Kconfig  |  26 ++++++++
 drivers/firmware/arm_rmm/Makefile |   2 +
 drivers/firmware/arm_rmm/rmi.c    | 101 ++++++++++++++++++++++++++++++
 include/linux/arm-rmi-cmds.h      |   2 +
 8 files changed, 135 insertions(+)
 create mode 100644 drivers/firmware/arm_rmm/Kconfig
 create mode 100644 drivers/firmware/arm_rmm/Makefile
 create mode 100644 drivers/firmware/arm_rmm/rmi.c

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b3afe0688919..0f1956edf130 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -38,6 +38,7 @@ config ARM64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_MEM_ENCRYPT
 	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
+	select ARCH_SUPPORTS_RMM
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9a22df0c5120..4ae63c89cda9 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -293,6 +293,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar3[] = {
 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV3_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV2_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_RME_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_DIT_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_AMU_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_MPAM_SHIFT, 4, 0),
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index 12dc70254842..55542879fbb8 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -301,5 +301,6 @@ source "drivers/firmware/samsung/Kconfig"
 source "drivers/firmware/smccc/Kconfig"
 source "drivers/firmware/tegra/Kconfig"
 source "drivers/firmware/xilinx/Kconfig"
+source "drivers/firmware/arm_rmm/Kconfig"
 
 endmenu
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index 4ddec2820c96..07e8ca1789b4 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -38,3 +38,4 @@ obj-y				+= samsung/
 obj-y				+= smccc/
 obj-y				+= tegra/
 obj-y				+= xilinx/
+obj-y				+= arm_rmm/
diff --git a/drivers/firmware/arm_rmm/Kconfig b/drivers/firmware/arm_rmm/Kconfig
new file mode 100644
index 000000000000..6f154f7d55dc
--- /dev/null
+++ b/drivers/firmware/arm_rmm/Kconfig
@@ -0,0 +1,26 @@
+
+config ARCH_SUPPORTS_RMM
+	bool
+
+config ARM_RMM
+	bool "Realm Management Monitor (RMM) Support"
+	depends on ARCH_SUPPORTS_RMM
+	default y
+	help
+	  Support the Realm Management Monitor (RMM) on Arm systems that
+	  implement the Realm Management Extension (RME), as defined by the
+	  Arm Confidential Compute Architecture.
+
+	  The RMM runs at EL2 in the Realm world and provides the Realm
+	  Management Interface (RMI) used by a Normal World host to create,
+	  manage and run protected virtual machines called Realms. The RMM can
+	  also act as a TSM, as defined by the PCIe TDISP and can manage the
+	  PCI IDE setup for securing the PCIe links.
+
+	  This option builds the host-side RMI support used by KVM to detect a
+	  compatible RMM, configure it, manage delegated memory and enable
+	  Realm guests.
+
+	  Selecting this option does not by itself make Realm guests available:
+	  the system must also provide RME-capable hardware and firmware with a
+	  compatible RMM implementation.
diff --git a/drivers/firmware/arm_rmm/Makefile b/drivers/firmware/arm_rmm/Makefile
new file mode 100644
index 000000000000..51aef5cc04b0
--- /dev/null
+++ b/drivers/firmware/arm_rmm/Makefile
@@ -0,0 +1,2 @@
+
+obj-$(CONFIG_ARM_RMM)	= rmi.o
diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
new file mode 100644
index 000000000000..008a783407b4
--- /dev/null
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/memblock.h>
+#include <linux/arm-rmi-cmds.h>
+#include <linux/slab.h>
+
+#include <asm/memory.h>
+#include <asm/pgtable-hwdef.h>
+
+/* Currently only the first 2 registers are used by Linux */
+#define RMI_FEAT_REG_COUNT	2
+static __ro_after_init unsigned long rmi_feat_reg_cache[RMI_FEAT_REG_COUNT];
+
+unsigned long rmi_feat_reg(unsigned long id)
+{
+	if (WARN_ON(id >= RMI_FEAT_REG_COUNT))
+		return 0;
+
+	return rmi_feat_reg_cache[id];
+}
+EXPORT_SYMBOL_GPL(rmi_feat_reg);
+
+static int rmi_check_version(void)
+{
+	struct arm_smccc_res res;
+	unsigned short version_major, version_minor;
+	unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION,
+						     RMI_ABI_MINOR_VERSION);
+	unsigned long aa64pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
+
+	/* If RME isn't supported, then RMI can't be */
+	if (cpuid_feature_extract_unsigned_field(aa64pfr0, ID_AA64PFR0_EL1_RME_SHIFT) == 0)
+		return -ENXIO;
+
+	arm_smccc_1_1_invoke(SMC_RMI_VERSION, host_version, &res);
+
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+		return -ENXIO;
+
+	version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1);
+	version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1);
+
+	if (res.a0 != RMI_SUCCESS) {
+		unsigned short high_version_major, high_version_minor;
+
+		high_version_major = RMI_ABI_VERSION_GET_MAJOR(res.a2);
+		high_version_minor = RMI_ABI_VERSION_GET_MINOR(res.a2);
+
+		pr_err("Unsupported RMI ABI (v%d.%d - v%d.%d) we want v%d.%d\n",
+		       version_major, version_minor,
+		       high_version_major, high_version_minor,
+		       RMI_ABI_MAJOR_VERSION,
+		       RMI_ABI_MINOR_VERSION);
+		return -ENXIO;
+	}
+
+	pr_info("RMI ABI version %d.%d\n", version_major, version_minor);
+
+	return 0;
+}
+
+static int rmi_read_features(void)
+{
+	/*
+	 * Since we've negotiated a compatible version these feature registers
+	 * should always be available
+	 */
+	for (int i = 0; i < RMI_FEAT_REG_COUNT; i++) {
+		if (WARN_ON(rmi_features(i, &rmi_feat_reg_cache[i])))
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int __init arm64_init_rmi(void)
+{
+	int ret;
+
+	/* Continue without realm support if we can't agree on a version */
+	ret = rmi_check_version();
+	if (ret)
+		return ret;
+
+	ret = rmi_read_features();
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Note arm64_init_rmi() must be called before kvm_init_rmi() otherwise KVM
+ * will not support realm guests. subsys_initcall() is called before
+ * module_init() (used for KVM) so this is OK.
+ */
+subsys_initcall(arm64_init_rmi);
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index 5ee94da96e4a..c97a70e771a6 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -12,6 +12,8 @@
 
 #include <asm/page.h>
 
+unsigned long rmi_feat_reg(unsigned long id);
+
 /**
  * rmi_rmm_config_set() - Configure the RMM
  * @cfg_ptr: PA of a struct rmm_config
-- 
2.43.0

[PATCH v16 04/45] firmware: arm_rmm: Configure the RMM with the host's page size

[Steven Price]

RMM v2.0 brings the ability to set the RMM's granule size. Check the
feature registers and configure the RMM so that it matches the host's
page size. This means that operations can be done with a granularity
equal to PAGE_SIZE.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Actually check the feature register for the host's page-size support.
Changes since v14:
 * Move the implementation into drivers/firmware/arm_rmm.
Changes since v13:
 * Moved out of KVM.
---
 drivers/firmware/arm_rmm/rmi.c | 61 ++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index 008a783407b4..ff9f76cc199a 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -77,6 +77,63 @@ static int rmi_read_features(void)
 	return 0;
 }
 
+static int rmi_configure(void)
+{
+	unsigned long granule_feature;
+	unsigned long granule_size;
+	long rmi_ret;
+	int ret = 0;
+	struct rmm_config *config;
+
+	switch (PAGE_SIZE) {
+	case SZ_4K:
+		granule_size = RMI_GRANULE_SIZE_4KB;
+		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_4KB;
+		break;
+	case SZ_16K:
+		granule_size = RMI_GRANULE_SIZE_16KB;
+		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_16KB;
+		break;
+	case SZ_64K:
+		granule_size = RMI_GRANULE_SIZE_64KB;
+		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_64KB;
+		break;
+	default:
+		BUILD_BUG();
+	}
+
+	if (!(rmi_feat_reg(1) & granule_feature)) {
+		pr_err("RMM does not support %luKB granules\n",
+		       PAGE_SIZE >> 10);
+		return -ENXIO;
+	}
+
+	config = (struct rmm_config *)get_zeroed_page(GFP_KERNEL);
+	if (!config)
+		return -ENOMEM;
+
+	config->rmi_granule_size = granule_size;
+
+	/*
+	 * For now we set the tracking_region_size to 0 which is the only option
+	 * for 4KB PAGE_SIZE (1GB for 4KB PAGE_SIZE, 32MB/512MB for 16KB/64KB).
+	 * TODO: Support other tracking sizes via Kconfig option for other
+	 * PAGE_SIZES
+	 */
+	config->tracking_region_size = 0;
+
+	rmi_ret = rmi_rmm_config_set(virt_to_phys(config));
+	if (rmi_ret) {
+		pr_err("RMM config set failed\n");
+		ret = -EINVAL;
+		goto out_free_config;
+	}
+
+out_free_config:
+	free_page((unsigned long)config);
+	return ret;
+}
+
 static int __init arm64_init_rmi(void)
 {
 	int ret;
@@ -90,6 +147,10 @@ static int __init arm64_init_rmi(void)
 	if (ret)
 		return ret;
 
+	ret = rmi_configure();
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
-- 
2.43.0

[PATCH v16 05/45] firmware: arm_rmm: Add support for SRO

[Steven Price]

RMM v2.0 introduces the concept of "Stateful RMI Operations" (SRO). This
means that an SMC can return with an operation still in progress. The
host is expected to continue the operation until it reaches a conclusion
(either success or failure). During this process the RMM can request
additional memory ('donate') or hand memory back to the host
('reclaim'). The host can request an in progress operation is cancelled,
but still continue the operation until it has completed (otherwise the
incomplete operation may cause future RMM operations to fail).

The SRO is tracked using a struct rmi_sro_state object which keeps track
of any memory which has been allocated but not yet consumed by the RMM
or reclaimed from the RMM. This allows the memory to be reused in a
future request within the same operation. It will also permit an
operation to be done in a context where memory allocation may be
difficult (e.g. atomic context) with the option to abort the operation
and retry the memory allocation outside of the atomic context. The
memory stored in the struct rmi_sro_state object can then be reused on
the subsequent attempt.

Wrappers for SRO RMI commands are also provided here because they depend
on the rmi_sro_execute() implementation added by this patch.
Delegate/undelegate handles are also added here because they now use the
SRO/stateful command infrastructure.

Signed-off-by: Steven Price <steven.price@arm.com>
---
v16:
 * Wrappers for realm guests split into a separate patch.
 * Better support for cancellation - previously a cancelled operation
   could be treated as successful.
 * Consistently use a signed type for wrapper return values so that
   Linux error codes can be returned as well as RMI return values.
v15:
 * Wrappers for SRO RMI functions are provided in this patch due to
   their dependency on the SRO infrastructure.
 * Fold the range delegate/undelegate wrappers into this patch because
   they depend on the stateful command infrastructure.
 * Add cpu_relax() calls when RMI_BUSY/RMI_BLOCKED is returned.
 * Various fixes.
v14:
 * SRO support has improved although is still not fully complete. The
   infrastructure has been moved out of KVM.
---
 drivers/firmware/arm_rmm/rmi.c | 515 ++++++++++++++++++++++++++++++++-
 include/linux/arm-rmi-cmds.h   | 114 ++++++++
 2 files changed, 628 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index ff9f76cc199a..51ea661cecf9 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -6,6 +6,7 @@
 #include <linux/cpufeature.h>
 #include <linux/memblock.h>
 #include <linux/arm-rmi-cmds.h>
+#include <linux/processor.h>
 #include <linux/slab.h>
 
 #include <asm/memory.h>
@@ -24,6 +25,502 @@ unsigned long rmi_feat_reg(unsigned long id)
 }
 EXPORT_SYMBOL_GPL(rmi_feat_reg);
 
+int rmi_delegate_range(phys_addr_t phys,
+		       unsigned long size,
+		       phys_addr_t *out_phys)
+{
+	long ret = 0;
+	unsigned long top = phys + size;
+	unsigned long out_top;
+
+	while (phys < top) {
+		ret = rmi_granule_range_delegate(phys, top, &out_top);
+		if (ret == RMI_SUCCESS)
+			phys = out_top;
+		else if (ret == RMI_BUSY || ret == RMI_BLOCKED)
+			cpu_relax();
+		else
+			break;
+	}
+
+	if (out_phys)
+		*out_phys = phys;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rmi_delegate_range);
+
+int rmi_undelegate_range(phys_addr_t phys,
+			 unsigned long size)
+{
+	long ret = 0;
+	unsigned long top = phys + size;
+	unsigned long out_top;
+
+	while (phys < top) {
+		ret = rmi_granule_range_undelegate(phys, top, &out_top);
+		if (ret == RMI_SUCCESS)
+			phys = out_top;
+		else if (ret == RMI_BUSY || ret == RMI_BLOCKED)
+			cpu_relax();
+		else
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rmi_undelegate_range);
+
+static unsigned long donate_req_to_size(unsigned long donatereq)
+{
+	unsigned long unit_size = RMI_DONATE_SIZE(donatereq);
+
+	return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(3 - unit_size));
+}
+
+static void rmi_smccc_invoke(struct arm_smccc_1_2_regs *regs_in,
+			     struct arm_smccc_1_2_regs *regs_out)
+{
+	struct arm_smccc_1_2_regs regs = *regs_in;
+	unsigned long status;
+
+	while (1) {
+		arm_smccc_1_2_invoke(&regs, regs_out);
+		status = RMI_RETURN_STATUS(regs_out->a0);
+		if (status != RMI_BUSY && status != RMI_BLOCKED)
+			break;
+		cpu_relax();
+	}
+}
+
+static void rmi_op_continue(unsigned long sro_handle, unsigned long flags,
+			    struct arm_smccc_1_2_regs *out_regs)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_OP_CONTINUE, sro_handle, flags
+	};
+
+	rmi_smccc_invoke(&regs, out_regs);
+}
+
+static void rmi_op_cancel(unsigned long sro_handle,
+			  struct arm_smccc_1_2_regs *out_regs)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_OP_CANCEL, sro_handle
+	};
+
+	rmi_smccc_invoke(&regs, out_regs);
+}
+
+static void rmi_op_mem_donate(unsigned long sro_handle, unsigned long list_addr,
+			      unsigned long list_count, unsigned long flags,
+			      struct arm_smccc_1_2_regs *out_regs)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_OP_MEM_DONATE, sro_handle, list_addr, list_count, flags
+	};
+
+	rmi_smccc_invoke(&regs, out_regs);
+}
+
+static void rmi_op_mem_reclaim(unsigned long sro_handle,
+			       unsigned long list_addr,
+			       unsigned long list_count,
+			       struct arm_smccc_1_2_regs *out_regs)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_OP_MEM_RECLAIM, sro_handle, list_addr, list_count
+	};
+
+	rmi_smccc_invoke(&regs, out_regs);
+}
+
+int free_delegated_page(phys_addr_t phys)
+{
+	if (WARN_ON_ONCE(rmi_undelegate_page(phys))) {
+		/* Undelegate failed: leak the page */
+		return -EBUSY;
+	}
+
+	free_page((unsigned long)phys_to_virt(phys));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(free_delegated_page);
+
+static int rmi_sro_ensure_capacity(struct rmi_sro_state *sro,
+				   unsigned long count)
+{
+	if (WARN_ON_ONCE(sro->addr_count > RMI_MAX_ADDR_LIST))
+		return -EOVERFLOW;
+
+	if (count > RMI_MAX_ADDR_LIST - sro->addr_count)
+		return -ENOSPC;
+
+	return 0;
+}
+
+static int rmi_sro_donate_contig(struct rmi_sro_state *sro,
+				 unsigned long sro_handle,
+				 unsigned long donatereq,
+				 struct arm_smccc_1_2_regs *out_regs,
+				 gfp_t gfp)
+{
+	unsigned long unit_size = RMI_DONATE_SIZE(donatereq);
+	unsigned long unit_size_bytes = donate_req_to_size(donatereq);
+	unsigned long count = RMI_DONATE_COUNT(donatereq);
+	unsigned long state = RMI_DONATE_STATE(donatereq);
+	unsigned long size = unit_size_bytes * count;
+	unsigned long addr_range;
+	int ret;
+	void *virt;
+	phys_addr_t phys;
+
+	/*
+	 * The RMM specification requires contiguous allocations are always a
+	 * power of 2
+	 */
+	if (WARN_ON_ONCE(!is_power_of_2(size)))
+		return -EINVAL;
+
+	for (int i = 0; i < sro->addr_count; i++) {
+		unsigned long entry = sro->addr_list[i];
+
+		if (RMI_ADDR_RANGE_SIZE(entry) == unit_size &&
+		    RMI_ADDR_RANGE_COUNT(entry) == count &&
+		    RMI_ADDR_RANGE_STATE(entry) == state &&
+		    IS_ALIGNED(RMI_ADDR_RANGE_ADDR(entry), size)) {
+			sro->addr_count--;
+			swap(sro->addr_list[sro->addr_count],
+			     sro->addr_list[i]);
+
+			goto out;
+		}
+	}
+
+	ret = rmi_sro_ensure_capacity(sro, 1);
+	if (ret)
+		return ret;
+
+	virt = alloc_pages_exact(size, gfp);
+	if (!virt)
+		return -ENOMEM;
+	phys = virt_to_phys(virt);
+
+	if (state == RMI_OP_MEM_DELEGATED) {
+		phys_addr_t delegated_phys;
+
+		if (rmi_delegate_range(phys, size, &delegated_phys)) {
+			if (!rmi_undelegate_range(phys, delegated_phys - phys))
+				free_pages_exact(virt, size);
+			return -ENXIO;
+		}
+	}
+
+	addr_range = phys & RMI_ADDR_RANGE_ADDR_MASK;
+	FIELD_MODIFY(RMI_ADDR_RANGE_SIZE_MASK, &addr_range, unit_size);
+	FIELD_MODIFY(RMI_ADDR_RANGE_COUNT_MASK, &addr_range, count);
+	FIELD_MODIFY(RMI_ADDR_RANGE_STATE_MASK, &addr_range, state);
+
+	sro->addr_list[sro->addr_count] = addr_range;
+
+out:
+	rmi_op_mem_donate(sro_handle,
+			  virt_to_phys(&sro->addr_list[sro->addr_count]), 1,
+			  0, out_regs);
+
+	unsigned long donated_granules = out_regs->a1;
+	unsigned long donated_size = donated_granules << PAGE_SHIFT;
+
+	if (donated_granules == 0) {
+		/* No pages used by the RMM */
+		sro->addr_count++;
+	} else if (donated_size < size) {
+		phys = sro->addr_list[sro->addr_count] & RMI_ADDR_RANGE_ADDR_MASK;
+
+		/* Not all granules used by the RMM, free the remaining pages */
+		for (long i = donated_size; i < size; i += PAGE_SIZE) {
+			if (state == RMI_OP_MEM_DELEGATED)
+				free_delegated_page(phys + i);
+			else
+				__free_page(phys_to_page(phys + i));
+		}
+	}
+
+	return 0;
+}
+
+static int rmi_sro_donate_noncontig(struct rmi_sro_state *sro,
+				    unsigned long sro_handle,
+				    unsigned long donatereq,
+				    struct arm_smccc_1_2_regs *out_regs,
+				    gfp_t gfp)
+{
+	unsigned long unit_size = RMI_DONATE_SIZE(donatereq);
+	unsigned long unit_size_bytes = donate_req_to_size(donatereq);
+	unsigned long count = RMI_DONATE_COUNT(donatereq);
+	unsigned long state = RMI_DONATE_STATE(donatereq);
+	unsigned long found = 0;
+	unsigned long addr_list_start = sro->addr_count;
+	int ret;
+
+	for (int i = 0; i < addr_list_start && found < count; i++) {
+		unsigned long entry = sro->addr_list[i];
+
+		if (RMI_ADDR_RANGE_SIZE(entry) == unit_size &&
+		    RMI_ADDR_RANGE_COUNT(entry) == 1 &&
+		    RMI_ADDR_RANGE_STATE(entry) == state) {
+			addr_list_start--;
+			swap(sro->addr_list[addr_list_start],
+			     sro->addr_list[i]);
+			found++;
+			i--;
+		}
+	}
+
+	ret = rmi_sro_ensure_capacity(sro, count - found);
+	if (ret)
+		return ret;
+
+	while (found < count) {
+		unsigned long addr_range;
+		void *virt = alloc_pages_exact(unit_size_bytes, gfp);
+		phys_addr_t phys;
+
+		if (!virt)
+			return -ENOMEM;
+
+		phys = virt_to_phys(virt);
+
+		if (state == RMI_OP_MEM_DELEGATED) {
+			phys_addr_t delegated_phys;
+
+			if (rmi_delegate_range(phys, unit_size_bytes,
+					       &delegated_phys)) {
+				if (!rmi_undelegate_range(phys, delegated_phys - phys))
+					free_pages_exact(virt, unit_size_bytes);
+				return -ENXIO;
+			}
+		}
+
+		addr_range = phys & RMI_ADDR_RANGE_ADDR_MASK;
+		FIELD_MODIFY(RMI_ADDR_RANGE_SIZE_MASK, &addr_range, unit_size);
+		FIELD_MODIFY(RMI_ADDR_RANGE_COUNT_MASK, &addr_range, 1);
+		FIELD_MODIFY(RMI_ADDR_RANGE_STATE_MASK, &addr_range, state);
+
+		sro->addr_list[sro->addr_count++] = addr_range;
+		found++;
+	}
+
+	rmi_op_mem_donate(sro_handle,
+			  virt_to_phys(&sro->addr_list[addr_list_start]),
+			  found, 0, out_regs);
+
+	unsigned long donated_granules = out_regs->a1;
+	unsigned long granules_per_unit = unit_size_bytes >> PAGE_SHIFT;
+	unsigned long consumed_units;
+
+	/*
+	 * The RMM shouldn't report more granules than we provided, but clamp
+	 * just in case.
+	 */
+	if (WARN_ON_ONCE(donated_granules > found * granules_per_unit))
+		donated_granules = found * granules_per_unit;
+
+	/*
+	 * The RMM reports the consumed memory in terms of granules, but we
+	 * track in the address lists in unit-sized ranges. So divide to get
+	 * the number of (complete) consumed units.
+	 */
+	consumed_units = donated_granules / granules_per_unit;
+	if (donated_granules % granules_per_unit) {
+		/*
+		 * A unit has been partially consumed, the start is owned by
+		 * the RMM, the tail is owned by the host
+		 */
+		unsigned long entry =
+			sro->addr_list[addr_list_start + consumed_units];
+		phys_addr_t phys = RMI_ADDR_RANGE_ADDR(entry);
+		unsigned long donated_size =
+			(donated_granules % granules_per_unit) << PAGE_SHIFT;
+
+		/* Free the tail back */
+		for (unsigned long i = donated_size; i < unit_size_bytes;
+		     i += PAGE_SIZE) {
+			if (state == RMI_OP_MEM_DELEGATED)
+				free_delegated_page(phys + i);
+			else
+				__free_page(phys_to_page(phys + i));
+		}
+
+		/*
+		 * This unit is now fully 'consumed' (either held by the RMM or
+		 * freed)
+		 */
+		consumed_units++;
+	}
+
+	/* Keep just the units the RMM didn't use in addr_list */
+	for (unsigned long i = consumed_units; i < found; i++)
+		sro->addr_list[addr_list_start + i - consumed_units] =
+			sro->addr_list[addr_list_start + i];
+
+	sro->addr_count -= consumed_units;
+
+	return 0;
+}
+
+static int rmi_sro_donate(struct rmi_sro_state *sro,
+			  unsigned long sro_handle,
+			  unsigned long donatereq,
+			  struct arm_smccc_1_2_regs *regs,
+			  gfp_t gfp)
+{
+	if (WARN_ON_ONCE(!RMI_DONATE_COUNT(donatereq)))
+		return -EINVAL;
+
+	if (RMI_DONATE_CONTIG(donatereq)) {
+		return rmi_sro_donate_contig(sro, sro_handle, donatereq,
+					     regs, gfp);
+	} else {
+		return rmi_sro_donate_noncontig(sro, sro_handle, donatereq,
+						regs, gfp);
+	}
+}
+
+static int rmi_sro_reclaim(struct rmi_sro_state *sro,
+			   unsigned long sro_handle,
+			   struct arm_smccc_1_2_regs *out_regs)
+{
+	unsigned long capacity;
+	int ret;
+
+	ret = rmi_sro_ensure_capacity(sro, 1);
+	if (ret)
+		rmi_sro_free(sro);
+
+	capacity = RMI_MAX_ADDR_LIST - sro->addr_count;
+
+	rmi_op_mem_reclaim(sro_handle,
+			   virt_to_phys(&sro->addr_list[sro->addr_count]),
+			   capacity, out_regs);
+
+	if (WARN_ON_ONCE(out_regs->a1 > capacity))
+		out_regs->a1 = capacity;
+
+	sro->addr_count += out_regs->a1;
+
+	return 0;
+}
+
+void rmi_sro_free(struct rmi_sro_state *sro)
+{
+	for (int i = 0; i < sro->addr_count; i++) {
+		unsigned long entry = sro->addr_list[i];
+		unsigned long addr = RMI_ADDR_RANGE_ADDR(entry);
+		unsigned long unit_size = RMI_ADDR_RANGE_SIZE(entry);
+		unsigned long count = RMI_ADDR_RANGE_COUNT(entry);
+		unsigned long state = RMI_ADDR_RANGE_STATE(entry);
+		unsigned long size = donate_req_to_size(unit_size) * count;
+
+		if (state == RMI_OP_MEM_DELEGATED) {
+			if (WARN_ON_ONCE(rmi_undelegate_range(addr, size))) {
+				/* Leak the pages */
+				continue;
+			}
+		}
+		free_pages_exact(phys_to_virt(addr), size);
+	}
+
+	sro->addr_count = 0;
+}
+EXPORT_SYMBOL_GPL(rmi_sro_free);
+
+long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp)
+{
+	unsigned long sro_handle;
+	struct arm_smccc_1_2_regs *regs = &sro->regs;
+	bool cancelled = false;
+
+	rmi_smccc_invoke(regs, regs);
+
+	sro_handle = regs->a1;
+
+	while (RMI_RETURN_STATUS(regs->a0) == RMI_INCOMPLETE) {
+		bool can_cancel = RMI_RETURN_CAN_CANCEL(regs->a0);
+		int ret = 0;
+
+		switch (RMI_RETURN_MEMREQ(regs->a0)) {
+		case RMI_OP_MEM_REQ_NONE:
+			rmi_op_continue(sro_handle, RMI_CONTINUE_KEEP_GOING,
+					regs);
+			break;
+		case RMI_OP_MEM_REQ_DONATE:
+			ret = rmi_sro_donate(sro, sro_handle, regs->a2, regs,
+					     gfp);
+			break;
+		case RMI_OP_MEM_REQ_RECLAIM:
+			ret = rmi_sro_reclaim(sro, sro_handle, regs);
+			break;
+		default:
+			ret = WARN_ON_ONCE(1);
+			break;
+		}
+
+		if (ret) {
+			if (can_cancel) {
+				rmi_op_cancel(sro_handle, regs);
+				cancelled = true;
+			}
+
+			if (WARN_ON_ONCE(RMI_RETURN_STATUS(regs->a0) != RMI_INCOMPLETE))
+				return ret;
+		}
+	}
+
+	if (cancelled)
+		return -ECANCELED;
+
+	return regs->a0;
+}
+EXPORT_SYMBOL_GPL(rmi_sro_memxfer_execute);
+
+/* For RMI commands that are stateful but not memory-transferring */
+long rmi_sro_execute(struct arm_smccc_1_2_regs *regs)
+{
+	unsigned long sro_handle;
+	bool cancelled = false;
+
+	rmi_smccc_invoke(regs, regs);
+
+	sro_handle = regs->a1;
+
+	while (RMI_RETURN_STATUS(regs->a0) == RMI_INCOMPLETE) {
+		bool can_cancel = RMI_RETURN_CAN_CANCEL(regs->a0);
+
+		switch (RMI_RETURN_MEMREQ(regs->a0)) {
+		case RMI_OP_MEM_REQ_NONE:
+			rmi_op_continue(sro_handle, RMI_CONTINUE_KEEP_GOING,
+					regs);
+			break;
+		default:
+			WARN_ON_ONCE(1);
+			if (!can_cancel)
+				return regs->a0;
+
+			cancelled = true;
+			rmi_op_cancel(sro_handle, regs);
+		}
+	}
+
+	if (cancelled)
+		return -ECANCELED;
+
+	return regs->a0;
+}
+EXPORT_SYMBOL_GPL(rmi_sro_execute);
+
 static int rmi_check_version(void)
 {
 	struct arm_smccc_res res;
@@ -84,6 +581,7 @@ static int rmi_configure(void)
 	long rmi_ret;
 	int ret = 0;
 	struct rmm_config *config;
+	struct rmi_sro_state *sro;
 
 	switch (PAGE_SIZE) {
 	case SZ_4K:
@@ -112,6 +610,12 @@ static int rmi_configure(void)
 	if (!config)
 		return -ENOMEM;
 
+	sro = kmalloc_obj(*sro);
+	if (!sro) {
+		ret = -ENOMEM;
+		goto out_free_config;
+	}
+
 	config->rmi_granule_size = granule_size;
 
 	/*
@@ -126,9 +630,18 @@ static int rmi_configure(void)
 	if (rmi_ret) {
 		pr_err("RMM config set failed\n");
 		ret = -EINVAL;
-		goto out_free_config;
+		goto out_free_sro;
+	}
+
+	rmi_ret = rmi_rmm_activate(sro);
+	if (rmi_ret) {
+		pr_err("RMM activate failed\n");
+		ret = rmi_ret < 0 ? rmi_ret : -ENXIO;
+		goto out_free_sro;
 	}
 
+out_free_sro:
+	kfree(sro);
 out_free_config:
 	free_page((unsigned long)config);
 	return ret;
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index c97a70e771a6..8814708536d6 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -12,8 +12,43 @@
 
 #include <asm/page.h>
 
+#define RMI_MAX_ADDR_LIST	256
+
+struct rmi_sro_state {
+	struct arm_smccc_1_2_regs regs;
+	unsigned long addr_count;
+	unsigned long addr_list[RMI_MAX_ADDR_LIST];
+};
+
 unsigned long rmi_feat_reg(unsigned long id);
 
+int rmi_delegate_range(phys_addr_t phys, unsigned long size,
+		       phys_addr_t *out_phys);
+int rmi_undelegate_range(phys_addr_t phys, unsigned long size);
+int free_delegated_page(phys_addr_t phys);
+
+static inline int rmi_delegate_page(phys_addr_t phys)
+{
+	return rmi_delegate_range(phys, PAGE_SIZE, NULL);
+}
+
+static inline int rmi_undelegate_page(phys_addr_t phys)
+{
+	return rmi_undelegate_range(phys, PAGE_SIZE);
+}
+
+long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp);
+void rmi_sro_free(struct rmi_sro_state *sro);
+long rmi_sro_execute(struct arm_smccc_1_2_regs *regs);
+
+#define rmi_sro_memxfer_cmd(sro, gfp, ...) ({				\
+	struct rmi_sro_state *__sro = (sro);				\
+	*__sro = (struct rmi_sro_state){ .regs = {__VA_ARGS__} };	\
+	long __ret = rmi_sro_memxfer_execute(__sro, gfp);		\
+	rmi_sro_free(__sro);						\
+	__ret;								\
+})
+
 /**
  * rmi_rmm_config_set() - Configure the RMM
  * @cfg_ptr: PA of a struct rmm_config
@@ -31,6 +66,17 @@ static inline int rmi_rmm_config_set(unsigned long cfg_ptr)
 	return res.a0;
 }
 
+/**
+ * rmi_rmm_activate() - Activate the RMM
+ * @sro: Preallocated SRO context to be used
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rmm_activate(struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL, SMC_RMI_RMM_ACTIVATE);
+}
+
 /**
  * rmi_granule_tracking_get() - Get configuration of a Granule tracking region
  * @start: Base PA of the tracking region
@@ -63,6 +109,21 @@ static inline int rmi_granule_tracking_get(unsigned long start,
 	return res.a0;
 }
 
+/**
+ * rmi_gpt_l1_create() - Create a Level 1 GPT
+ * @addr: Base of physical address region described by the L1GPT
+ * @sro: Preallocated SRO context to be used
+ * @gfp: Allocation flags for SRO memory donation requests
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_gpt_l1_create(unsigned long addr,
+				     struct rmi_sro_state *sro,
+				     gfp_t gfp)
+{
+	return rmi_sro_memxfer_cmd(sro, gfp, SMC_RMI_GPT_L1_CREATE, addr);
+}
+
 /**
  * rmi_features() - Read feature register
  * @index: Feature register index
@@ -82,4 +143,57 @@ static inline int rmi_features(unsigned long index, unsigned long *out)
 	return res.a0;
 }
 
+/**
+ * rmi_granule_range_delegate() - Delegate granules
+ * @base: PA of the first granule of the range
+ * @top: PA of the first granule after the range
+ * @out_top: PA of the first granule not delegated
+ *
+ * Delegate a range of granule for use by the realm world. If the entire range
+ * was delegated then @out_top == @top, otherwise the function should be called
+ * again with @base == @out_top.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_granule_range_delegate(unsigned long base,
+					      unsigned long top,
+					      unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_GRANULE_RANGE_DELEGATE, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_granule_range_undelegate() - Undelegate a range of granules
+ * @base: Base PA of the target range
+ * @top: Top PA of the target range
+ * @out_top: Returns the top PA of range whose state is undelegated
+ *
+ * Undelegate a range of granules to allow use by the normal world. Will fail if
+ * the granules are in use.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_granule_range_undelegate(unsigned long base,
+						unsigned long top,
+						unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_GRANULE_RANGE_UNDELEGATE, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
 #endif
-- 
2.43.0

[PATCH v16 06/45] firmware: arm_rmm: Ensure the RMM has GPT entries for memory

[Steven Price]

The RMM maintains the state of all the granules in the system to make
sure that the host is abiding by the rules. This state can be maintained
at different granularity, per page (TRACKING_FINE) or per region
(TRACKING_COARSE). The region size depends on the underlying
"RMI_GRANULE_SIZE". For a "coarse" region all pages in the region must
be of the same state, this implies we need to have "fine" tracking for
DRAM, so that we can delegate individual pages.

For now we only support a statically carved out memory for tracking
granules for the "fine" regions. This can be extended in the future to
allow modifying the tracking granularity and remove the need for a
static allocation.

Similarly, the firmware may create L0 GPT entries describing the total
address space. But if we change the "PAS" (Physical Address Space) of a
granule then the firmware may need to create L1 tables to track the PAS
at a finer granularity.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Skip firmware-reserved NOMAP memory in rmi_init_metadata()
 * Handle negative error codes from wrappers.
Changes since v14:
 * Move the implementation into drivers/firmware/arm_rmm.
Changes since v13:
 * Moved out of KVM
---
 drivers/firmware/arm_rmm/rmi.c | 101 +++++++++++++++++++++++++++++++++
 include/linux/arm-rmi-cmds.h   |   2 +
 2 files changed, 103 insertions(+)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index 51ea661cecf9..bce3304bbc1a 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -12,6 +12,8 @@
 #include <asm/memory.h>
 #include <asm/pgtable-hwdef.h>
 
+static bool arm64_rmi_is_available;
+
 /* Currently only the first 2 registers are used by Linux */
 #define RMI_FEAT_REG_COUNT	2
 static __ro_after_init unsigned long rmi_feat_reg_cache[RMI_FEAT_REG_COUNT];
@@ -647,6 +649,98 @@ static int rmi_configure(void)
 	return ret;
 }
 
+/*
+ * Make sure the area is tracked by RMM at FINE granularity.
+ * We do not support changing the tracking yet.
+ */
+static int rmi_verify_memory_tracking(phys_addr_t start, phys_addr_t end)
+{
+	while (start < end) {
+		unsigned long ret, category, state, next;
+
+		ret = rmi_granule_tracking_get(start, end, &category, &state, &next);
+		if (ret != RMI_SUCCESS ||
+		    state != RMI_TRACKING_FINE ||
+		    category != RMI_MEM_CATEGORY_CONVENTIONAL) {
+			/* TODO: Set granule tracking in this case */
+			pr_err("Granule tracking for region isn't fine/conventional: %llx\n",
+			       start);
+			return -ENODEV;
+		}
+		start = next;
+	}
+
+	return 0;
+}
+
+static int rmi_create_gpts(phys_addr_t start, phys_addr_t end)
+{
+	struct rmi_sro_state *sro;
+	unsigned long l0gpt_sz;
+
+	sro = kmalloc_obj(*sro, GFP_KERNEL);
+	if (!sro)
+		return -ENOMEM;
+
+	l0gpt_sz = 1UL << (30 + FIELD_GET(RMI_FEATURE_REGISTER_1_L0GPTSZ,
+					  rmi_feat_reg(1)));
+	start = ALIGN_DOWN(start, l0gpt_sz);
+	end = ALIGN(end, l0gpt_sz);
+
+	while (start < end) {
+		long ret = rmi_gpt_l1_create(start, sro, GFP_KERNEL);
+
+		/*
+		 * Make sure the L1 GPT tables are created for the region.
+		 * RMI_ERROR_GPT indicates the L1 table already exists.
+		 */
+		if (ret < 0) {
+			kfree(sro);
+			return ret;
+		}
+
+		if (ret != RMI_SUCCESS && RMI_RETURN_STATUS(ret) != RMI_ERROR_GPT) {
+			pr_err("GPT Level1 table missing for %llx\n", start);
+			kfree(sro);
+			return -ENOMEM;
+		}
+		start += l0gpt_sz;
+	}
+
+	kfree(sro);
+	return 0;
+}
+
+static int rmi_init_metadata(void)
+{
+	phys_addr_t start, end;
+	struct memblock_region *r;
+
+	for_each_mem_region(r) {
+		int ret;
+
+		/* Firmware-reserved NOMAP regions are not usable system RAM */
+		if (memblock_is_nomap(r))
+			continue;
+
+		start = memblock_region_memory_base_pfn(r) << PAGE_SHIFT;
+		end = memblock_region_memory_end_pfn(r) << PAGE_SHIFT;
+		ret = rmi_verify_memory_tracking(start, end);
+		if (ret)
+			return ret;
+		ret = rmi_create_gpts(start, end);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+bool is_rmi_available(void)
+{
+	return arm64_rmi_is_available;
+}
+
 static int __init arm64_init_rmi(void)
 {
 	int ret;
@@ -664,6 +758,13 @@ static int __init arm64_init_rmi(void)
 	if (ret)
 		return ret;
 
+	ret = rmi_init_metadata();
+	if (ret)
+		return ret;
+
+	arm64_rmi_is_available = true;
+	pr_info("RMI configured\n");
+
 	return 0;
 }
 
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index 8814708536d6..805a7ed9fc00 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -37,6 +37,8 @@ static inline int rmi_undelegate_page(phys_addr_t phys)
 	return rmi_undelegate_range(phys, PAGE_SIZE);
 }
 
+bool is_rmi_available(void);
+
 long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp);
 void rmi_sro_free(struct rmi_sro_state *sro);
 long rmi_sro_execute(struct arm_smccc_1_2_regs *regs);
-- 
2.43.0

[PATCH v16 07/45] arm64: mm: Handle Granule Protection Faults (GPFs)

[Steven Price]

If the host attempts to access granules that have been delegated for use
in a realm these accesses will be caught and will trigger a Granule
Protection Fault (GPF).

A fault during a page walk signals a bug in the kernel and is handled by
oopsing the kernel. A non-page walk fault could be caused by user space
having access to a page which has been delegated to the kernel and will
trigger a SIGBUS to allow debugging why user space is trying to access a
delegated page.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v10:
 * Don't call arm64_notify_die() in do_gpf() but simply return 1.
Changes since v2:
 * Include missing "Granule Protection Fault at level -1"
---
 arch/arm64/mm/fault.c | 28 ++++++++++++++++++++++------
 1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 85e23388f9bb..ea3ae0ca7dba 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -909,6 +909,22 @@ static int do_tag_check_fault(unsigned long far, unsigned long esr,
 	return 0;
 }
 
+static int do_gpf_ptw(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+	const struct fault_info *inf = esr_to_fault_info(esr);
+
+	die_kernel_fault(inf->name, far, esr, regs);
+	return 0;
+}
+
+static int do_gpf(unsigned long far, unsigned long esr, struct pt_regs *regs)
+{
+	if (!is_el1_instruction_abort(esr) && fixup_exception(regs, esr))
+		return 0;
+
+	return 1;
+}
+
 static const struct fault_info fault_info[] = {
 	{ do_bad,		SIGKILL, SI_KERNEL,	"ttbr address size fault"	},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"level 1 address size fault"	},
@@ -945,12 +961,12 @@ static const struct fault_info fault_info[] = {
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 32"			},
 	{ do_alignment_fault,	SIGBUS,  BUS_ADRALN,	"alignment fault"		},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 34"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 35"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 36"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 37"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 38"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 39"			},
-	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 40"			},
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"level -1 granule protection fault (translation table walk)" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"level 0 granule protection fault (translation table walk)" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"level 1 granule protection fault (translation table walk)" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"level 2 granule protection fault (translation table walk)" },
+	{ do_gpf_ptw,		SIGKILL, SI_KERNEL,	"level 3 granule protection fault (translation table walk)" },
+	{ do_gpf,		SIGBUS,  SI_KERNEL,	"granule protection fault" },
 	{ do_bad,		SIGKILL, SI_KERNEL,	"level -1 address size fault"	},
 	{ do_bad,		SIGKILL, SI_KERNEL,	"unknown 42"			},
 	{ do_translation_fault,	SIGSEGV, SEGV_MAPERR,	"level -1 translation fault"	},
-- 
2.43.0

[PATCH v16 08/45] KVM: arm64: Include kvm_emulate.h in kvm/arm_psci.h

[Steven Price]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

Fix a potential build error (like below, when asm/kvm_emulate.h gets
included after the kvm/arm_psci.h) by including the missing header file
in kvm/arm_psci.h:

./include/kvm/arm_psci.h: In function ‘kvm_psci_version’:
./include/kvm/arm_psci.h:29:13: error: implicit declaration of function
   ‘vcpu_has_feature’; did you mean ‘cpu_have_feature’? [-Werror=implicit-function-declaration]
   29 |         if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PSCI_0_2)) {
	         |             ^~~~~~~~~~~~~~~~
			       |             cpu_have_feature

Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
 include/kvm/arm_psci.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h
index cbaec804eb83..38dab7add79b 100644
--- a/include/kvm/arm_psci.h
+++ b/include/kvm/arm_psci.h
@@ -10,6 +10,8 @@
 #include <linux/kvm_host.h>
 #include <uapi/linux/psci.h>
 
+#include <asm/kvm_emulate.h>
+
 #define KVM_ARM_PSCI_0_1	PSCI_VERSION(0, 1)
 #define KVM_ARM_PSCI_0_2	PSCI_VERSION(0, 2)
 #define KVM_ARM_PSCI_1_0	PSCI_VERSION(1, 0)
-- 
2.43.0

[PATCH v16 09/45] KVM: arm64: Avoid including linux/kvm_host.h in kvm_pgtable.h

[Steven Price]

To avoid future include cycles, drop the linux/kvm_host.h include in
kvm_pgtable.h and include the lightweight headers required for the types
and inline helpers used there. Additionally provide a forward
declaration for struct kvm_s2_mmu as it's only used as a pointer in this
file.

Both pgtable.c and kvm_pkvm.h relied on the indirect inclusion of
kvm_host.h, so make that explicit.

Signed-off-by: Steven Price <steven.price@arm.com>
---
New patch in v13
---
 arch/arm64/include/asm/kvm_pgtable.h | 6 +++++-
 arch/arm64/include/asm/kvm_pkvm.h    | 2 +-
 arch/arm64/kvm/hyp/pgtable.c         | 1 +
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 41a8687938eb..c2e4b29e605f 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -8,9 +8,13 @@
 #define __ARM64_KVM_PGTABLE_H__
 
 #include <linux/bits.h>
-#include <linux/kvm_host.h>
+#include <linux/kvm_types.h>
+#include <linux/rbtree_types.h>
+#include <linux/rcupdate.h>
 #include <linux/types.h>
 
+struct kvm_s2_mmu;
+
 #define KVM_PGTABLE_FIRST_LEVEL		-1
 #define KVM_PGTABLE_LAST_LEVEL		3
 
diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h
index 74fedd9c5ff0..0afe742d1f3f 100644
--- a/arch/arm64/include/asm/kvm_pkvm.h
+++ b/arch/arm64/include/asm/kvm_pkvm.h
@@ -7,9 +7,9 @@
 #define __ARM64_KVM_PKVM_H__
 
 #include <linux/arm_ffa.h>
+#include <linux/kvm_host.h>
 #include <linux/memblock.h>
 #include <linux/scatterlist.h>
-#include <asm/kvm_host.h>
 #include <asm/kvm_pgtable.h>
 
 /* Maximum number of VMs that can co-exist under pKVM. */
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 91a7dfad6686..3d608b7e0cf0 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/kvm_host.h>
 #include <asm/kvm_pgtable.h>
 #include <asm/stage2_pgtable.h>
 
-- 
2.43.0

[PATCH v16 10/45] KVM: arm64: CCA: Add wrappers for realm related RMIs

[Steven Price]

Introduce wrappers for the RMI functions needed for creating and
managing realm guests.

Signed-off-by: Steven Price <steven.price@arm.com>
---
v16: Split into new patch
---
 arch/arm64/include/asm/rmi_cmds.h | 465 ++++++++++++++++++++++++++++++
 1 file changed, 465 insertions(+)
 create mode 100644 arch/arm64/include/asm/rmi_cmds.h

diff --git a/arch/arm64/include/asm/rmi_cmds.h b/arch/arm64/include/asm/rmi_cmds.h
new file mode 100644
index 000000000000..25185935bf3c
--- /dev/null
+++ b/arch/arm64/include/asm/rmi_cmds.h
@@ -0,0 +1,465 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ */
+
+#ifndef __ASM_RMI_CMDS_H
+#define __ASM_RMI_CMDS_H
+
+#include <linux/arm-rmi-cmds.h>
+#include <linux/arm-smccc-rmi.h>
+
+/**
+ * rmi_rtt_data_map_init() - Create a protected mapping with data contents
+ * @rd: PA of the RD
+ * @data: PA of the target granule
+ * @ipa: IPA at which the granule will be mapped in the guest
+ * @src: PA of the source granule
+ * @flags: RMI_MEASURE_CONTENT if the contents should be measured
+ *
+ * Create a mapping from Protected IPA space to conventional memory, copying
+ * contents from a Non-secure Granule provided by the caller.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_data_map_init(unsigned long rd, unsigned long data,
+					 unsigned long ipa, unsigned long src,
+					 unsigned long flags)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DATA_MAP_INIT, rd, data, ipa, src, flags
+	};
+
+	return rmi_sro_execute(&regs);
+}
+
+/**
+ * rmi_rtt_data_map() - Create mappings in protected IPA with unknown contents
+ * @rd: PA of the RD
+ * @base: Base of the target IPA range
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Top address of range which was processed.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_data_map(unsigned long rd,
+				    unsigned long base,
+				    unsigned long top,
+				    unsigned long flags,
+				    unsigned long oaddr,
+				    unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DATA_MAP, rd, base, top, flags, oaddr
+	};
+	long ret;
+
+	ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_data_unmap() - Remove mappings to conventional memory
+ * @rd: PA of the RD for the target Realm
+ * @base: Base of the target IPA range
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Returns top IPA of range which has been unmapped
+ * @out_range: Output address range
+ * @out_count: Number of entries in output address list
+ *
+ * Removes mappings to convention memory with a target Protected IPA range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_data_unmap(unsigned long rd,
+				      unsigned long base,
+				      unsigned long top,
+				      unsigned long flags,
+				      unsigned long oaddr,
+				      unsigned long *out_top,
+				      unsigned long *out_range,
+				      unsigned long *out_count)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DATA_UNMAP, rd, base, top, flags, oaddr
+	};
+	long ret;
+
+	ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS) {
+		if (out_top)
+			*out_top = regs.a1;
+		if (out_range)
+			*out_range = regs.a2;
+		if (out_count)
+			*out_count = regs.a3;
+	}
+
+	return ret;
+}
+
+/**
+ * rmi_psci_complete() - Complete pending PSCI command
+ * @calling_rec: PA of the calling REC
+ * @status: Status of the PSCI request
+ *
+ * Completes a pending PSCI command.
+ *
+ * Return: RMI return code
+ */
+static inline long rmi_psci_complete(unsigned long calling_rec,
+				     unsigned long status)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_PSCI_COMPLETE, calling_rec, status, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_realm_activate() - Active a realm
+ * @rd: PA of the RD
+ *
+ * Mark a realm as Active signalling that creation is complete and allowing
+ * execution of the realm.
+ *
+ * Return: RMI return code
+ */
+static inline long rmi_realm_activate(unsigned long rd)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REALM_ACTIVATE, rd, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_realm_create() - Create a realm
+ * @rd: PA of the RD
+ * @params: PA of realm parameters
+ * @sro: Preallocated SRO context to be used
+ *
+ * Create a new realm using the given parameters.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_realm_create(unsigned long rd, unsigned long params,
+				    struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL,
+				   SMC_RMI_REALM_CREATE, rd, params);
+}
+
+/**
+ * rmi_realm_terminate() - Terminate a realm
+ * @rd: PA of the RD
+ * @sro: Preallocated SRO context to be used
+ *
+ * Terminates a realm, moving it into a ZOMBIE state
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_realm_terminate(unsigned long rd,
+				       struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL,
+				   SMC_RMI_REALM_TERMINATE, rd);
+}
+
+/**
+ * rmi_realm_destroy() - Destroy a realm
+ * @rd: PA of the RD
+ * @sro: Preallocated SRO context to be used
+ *
+ * Destroys a realm, all objects belonging to the realm must be destroyed first.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_realm_destroy(unsigned long rd,
+				     struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL,
+				   SMC_RMI_REALM_DESTROY, rd);
+}
+
+/**
+ * rmi_rec_create() - Create a REC
+ * @rd: PA of the RD
+ * @rec: PA of the target REC
+ * @params: PA of REC parameters
+ * @sro: Allocated SRO context to be used
+ *
+ * Create a REC using the parameters specified in the struct rec_params pointed
+ * to by @params.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rec_create(unsigned long rd,
+				  unsigned long rec,
+				  unsigned long params,
+				  struct rmi_sro_state *sro)
+{
+	long ret;
+
+	*sro = (struct rmi_sro_state){.regs = {
+		SMC_RMI_REC_CREATE, rd, rec, params
+	}};
+	ret = rmi_sro_memxfer_execute(sro, GFP_KERNEL);
+	rmi_sro_free(sro);
+
+	return ret;
+}
+
+/**
+ * rmi_rec_destroy() - Destroy a REC
+ * @rec: PA of the target REC
+ * @sro: Allocated SRO context to be used
+ *
+ * Destroys a REC. The REC must not be running.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rec_destroy(unsigned long rec,
+				   struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL, SMC_RMI_REC_DESTROY, rec);
+}
+
+/**
+ * rmi_rec_enter() - Enter a REC
+ * @rec: PA of the target REC
+ * @run_ptr: PA of RecRun structure
+ *
+ * Starts (or continues) execution within a REC.
+ *
+ * Return: RMI return code
+ */
+static inline long rmi_rec_enter(unsigned long rec, unsigned long run_ptr)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RMI_REC_ENTER, rec, run_ptr, &res);
+
+	return res.a0;
+}
+
+/**
+ * rmi_rtt_create() - Creates an RTT
+ * @rd: PA of the RD
+ * @rtt: PA of the target RTT
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ *
+ * Creates an RTT (Realm Translation Table) at the specified level for the
+ * translation of the specified address within the realm.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_create(unsigned long rd, unsigned long rtt,
+				  unsigned long ipa, long level)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_CREATE, rd, rtt, ipa, level
+	};
+
+	return rmi_sro_execute(&regs);
+}
+
+/**
+ * rmi_rtt_destroy() - Destroy an RTT
+ * @rd: PA of the RD for the target realm
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: RTT level
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ * @out_top: Pointer to write the top IPA of non-live RTT entries, from entry
+ * at which the RTT walk terminated.
+ *
+ * Destroys an RTT. The RTT must be non-live, i.e. none of the entries in the
+ * table are in ASSIGNED or TABLE state.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code.
+ */
+static inline long rmi_rtt_destroy(unsigned long rd,
+				   unsigned long ipa,
+				   long level,
+				   unsigned long *out_rtt,
+				   unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DESTROY, rd, ipa, level
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS) {
+		if (out_rtt)
+			*out_rtt = regs.a1;
+		if (out_top)
+			*out_top = regs.a2;
+	}
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_fold() - Fold an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ *
+ * Folds an RTT. If all entries with the RTT are 'homogeneous' the RTT can be
+ * folded into the parent and the RTT destroyed.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_fold(unsigned long rd, unsigned long ipa,
+				long level, unsigned long *out_rtt)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_FOLD, rd, ipa, level
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_rtt)
+		*out_rtt = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_init_ripas() - Set RIPAS for new realm
+ * @rd: PA of the RD
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Top IPA of range whose RIPAS was modified
+ *
+ * Sets the RIPAS of a target IPA range to RAM, for a realm in the NEW state.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_init_ripas(unsigned long rd, unsigned long base,
+				      unsigned long top, unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_INIT_RIPAS, rd, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_unprot_map() - Map unprotected granules into a realm
+ * @rd: PA of the RD
+ * @base: Base IPA of the mapping
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Top IPA of range which has been mapped
+ *
+ * Create mappings to memory within a target unprotected IPA range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_unprot_map(unsigned long rd,
+				      unsigned long base,
+				      unsigned long top,
+				      unsigned long flags,
+				      unsigned long oaddr,
+				      unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_UNPROT_MAP, rd, base, top, flags, oaddr
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_set_ripas() - Set RIPAS for an running realm
+ * @rd: PA of the RD
+ * @rec: PA of the REC making the request
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Pointer to write top IPA of range whose RIPAS was modified
+ *
+ * Completes a request made by the realm to change the RIPAS of a target IPA
+ * range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_set_ripas(unsigned long rd, unsigned long rec,
+				     unsigned long base, unsigned long top,
+				     unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_SET_RIPAS, rd, rec, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_unprot_unmap() - Remove mappings within an unprotected IPA range
+ * @rd: PA of the RD
+ * @base: Base IPA of the mapping
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Top IPA which has been unmapped
+ * @out_range: Output address range
+ * @out_count: Number of entries in output address list
+ *
+ * Removes mappings to memory within a target unprotected IPA range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_unprot_unmap(unsigned long rd,
+					unsigned long base,
+					unsigned long top,
+					unsigned long flags,
+					unsigned long oaddr,
+					unsigned long *out_top,
+					unsigned long *out_range,
+					unsigned long *out_count)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_UNPROT_UNMAP, rd, base, top, flags, oaddr
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS) {
+		if (out_top)
+			*out_top = regs.a1;
+		if (out_range)
+			*out_range = regs.a2;
+		if (out_count)
+			*out_count = regs.a3;
+	}
+
+	return ret;
+}
+
+#endif /* __ASM_RMI_CMDS_H */
-- 
2.43.0

[PATCH v16 11/45] KVM: arm64: CCA: Check for RMI support at KVM init

[Steven Price]

Check if the RMI support is sufficient for using in KVM. Specifically, we
currently only support creating realm VMs when KVM is running in VHE mode.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v13:
 * Most of the init has been moved out of the 'kvm' directory so this is
   much more basic now.
Changes since v12:
 * Drop check for 4k page size.
Changes since v11:
 * Reword slightly the comments on the realm states.
Changes since v10:
 * kvm_is_realm() no longer has a NULL check.
 * Rename from "rme" to "rmi" when referring to the RMM interface.
 * Check for RME (hardware) support before probing for RMI support.
Changes since v8:
 * No need to guard kvm_init_rme() behind 'in_hyp_mode'.
Changes since v6:
 * Improved message for an unsupported RMI ABI version.
Changes since v5:
 * Reword "unsupported" message from "host supports" to "we want" to
   clarify that 'we' are the 'host'.
Changes since v2:
 * Drop return value from kvm_init_rme(), it was always 0.
 * Rely on the RMM return value to identify whether the RSI ABI is
   compatible.
---
 arch/arm64/include/asm/kvm_host.h |  4 ++++
 arch/arm64/include/asm/kvm_rmi.h  | 17 +++++++++++++++++
 arch/arm64/include/asm/virt.h     |  1 +
 arch/arm64/kvm/Kconfig            |  1 +
 arch/arm64/kvm/Makefile           |  2 +-
 arch/arm64/kvm/arm.c              |  5 +++++
 arch/arm64/kvm/rmi.c              | 24 ++++++++++++++++++++++++
 7 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/include/asm/kvm_rmi.h
 create mode 100644 arch/arm64/kvm/rmi.c

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index bae2c4f92ef5..1a5e15040111 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -27,6 +27,7 @@
 #include <asm/fpsimd.h>
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
+#include <asm/kvm_rmi.h>
 #include <asm/vncr_mapping.h>
 
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED
@@ -424,6 +425,9 @@ struct kvm_arch {
 	/* Nested virtualization info */
 	struct dentry *debugfs_nv_dentry;
 #endif
+
+	bool is_realm;
+	struct realm realm;
 };
 
 struct kvm_vcpu_fault_info {
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
new file mode 100644
index 000000000000..57d24b244c95
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ */
+
+#ifndef __ASM_KVM_RMI_H
+#define __ASM_KVM_RMI_H
+
+/**
+ * struct realm - Additional per VM data for a Realm
+ */
+struct realm {
+};
+
+void kvm_init_rmi(void);
+
+#endif /* __ASM_KVM_RMI_H */
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index b546703c3ab9..92cec42952f4 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -87,6 +87,7 @@ void __hyp_reset_vectors(void);
 bool is_kvm_arm_initialised(void);
 
 DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
+DECLARE_STATIC_KEY_FALSE(kvm_rmi_is_available);
 
 static inline bool is_pkvm_initialized(void)
 {
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 449154f9a485..189e8ad78b22 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -37,6 +37,7 @@ menuconfig KVM
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
 	select KVM_GUEST_MEMFD
+	select ARM_RMM
 	help
 	  Support hosting virtualized guest machines.
 
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 59612d2f277c..ed3cf30eb06e 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -16,7 +16,7 @@ CFLAGS_handle_exit.o += -Wno-override-init
 kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
 	 inject_fault.o va_layout.o handle_exit.o config.o \
 	 guest.o debug.o reset.o sys_regs.o stacktrace.o \
-	 vgic-sys-reg-v3.o fpsimd.o pkvm.o \
+	 vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o \
 	 arch_timer.o trng.o vmid.o emulate-nested.o nested.o at.o \
 	 vgic/vgic.o vgic/vgic-init.o \
 	 vgic/vgic-irqfd.o vgic/vgic-v2.o \
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 50adfff75be8..b961c22fce3d 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -42,6 +42,7 @@
 #include <asm/kvm_nested.h>
 #include <asm/kvm_pkvm.h>
 #include <asm/kvm_ptrauth.h>
+#include <asm/kvm_rmi.h>
 #include <asm/sections.h>
 #include <asm/stacktrace/nvhe.h>
 
@@ -111,6 +112,8 @@ long kvm_get_cap_for_kvm_ioctl(unsigned int ioctl, long *ext)
 	return -EINVAL;
 }
 
+DEFINE_STATIC_KEY_FALSE(kvm_rmi_is_available);
+
 DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
 
 DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base);
@@ -3019,6 +3022,8 @@ static __init int kvm_arm_init(void)
 
 	in_hyp_mode = is_kernel_in_hyp_mode();
 
+	kvm_init_rmi();
+
 	if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
 	    cpus_have_final_cap(ARM64_WORKAROUND_1508412))
 		kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
new file mode 100644
index 000000000000..384991d69f78
--- /dev/null
+++ b/arch/arm64/kvm/rmi.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/rmi_cmds.h>
+#include <asm/virt.h>
+
+void kvm_init_rmi(void)
+{
+	/*
+	 * TODO: Support Realm guests in nVHE mode, this will require adding
+	 * EL2 stub(s) for REC entry and possibly other things.
+	 */
+	if (!is_kernel_in_hyp_mode())
+		return;
+
+	if (!is_rmi_available())
+		return;
+
+	/* Future patch will enable static branch kvm_rmi_is_available */
+}
-- 
2.43.0

[PATCH v16 12/45] KVM: arm64: CCA: Check for LPA2 support

[Steven Price]

If KVM has enabled LPA2 support then check that the RMM also supports
it. If there is a mismatch then disable support for realm guests as the
VMM may attempt to create a guest which is incompatible with the RMM.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
v15:
 * Extend rmi_has_feature() to take the register number and check the
   presence of SHA-256 support which is default.
v13:
 * New patch
---
 arch/arm64/kvm/rmi.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 384991d69f78..247c4f033945 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -5,9 +5,31 @@
 
 #include <linux/kvm_host.h>
 
+#include <asm/kvm_pgtable.h>
 #include <asm/rmi_cmds.h>
 #include <asm/virt.h>
 
+static bool rmi_has_feature(int reg, unsigned long feature)
+{
+	return !!u64_get_bits(rmi_feat_reg(reg), feature);
+}
+
+static int rmm_check_features(void)
+{
+	if (kvm_lpa2_is_enabled() &&
+	    !rmi_has_feature(0, RMI_FEATURE_REGISTER_0_LPA2)) {
+		kvm_err("RMM doesn't support LPA2\n");
+		return -ENXIO;
+	}
+
+	if (!rmi_has_feature(1, RMI_FEATURE_REGISTER_1_HASH_SHA_256)) {
+		kvm_err("RMM doesn't support SHA-256 measurements\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
 void kvm_init_rmi(void)
 {
 	/*
@@ -20,5 +42,8 @@ void kvm_init_rmi(void)
 	if (!is_rmi_available())
 		return;
 
+	if (rmm_check_features())
+		return;
+
 	/* Future patch will enable static branch kvm_rmi_is_available */
 }
-- 
2.43.0

[PATCH v16 13/45] KVM: arm64: CCA: Define the user ABI

[Steven Price]

There is one CAP (KVM_CAP_ARM_RMI) which identifies the presence of CCA,
and one ioctl.  The ioctl (KVM_ARM_RMI_POPULATE) is used to populate
memory during creation of the realm as this requires the RMM to copy
data from an unprotected address to the protected memory - CCA does not
support shared <-> private memory conversion where the memory contents
is preserved as this is incompatible with memory encryption.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Expand KVM_ARM_RMI_POPULATE documentation to be explicit that
   in-place shared-to-private conversion isn't supported.
Changes since v13:
 * KVM_ARM_VCPU_RMI_PSCI_COMPLETE removed.
 * KVM_ARM_RMI_POPULATE documentation updated to reflect that the
   structure is written by the kernel.
 * CAP number bumped.
Changes since v12:
 * Change KVM_ARM_RMI_POPULATE to update the structure with the amount
   that has been progressed rather than return the number of bytes
   populated.
 * Describe the flag KVM_ARM_RMI_POPULATE_FLAGS_MEASURE.
 * CAP number is bumped.
 * NOTE: The PSCI ioctl may be removed in a future spec release.
Changes since v11:
 * Completely reworked to be more implicit. Rather than having explicit
   CAP operations to progress the realm construction these operations
   are done when needed (on populating and on first vCPU run).
 * Populate and PSCI complete are promoted to proper ioctls.
Changes since v10:
 * Rename symbols from RME to RMI.
Changes since v9:
 * Improvements to documentation.
 * Bump the magic number for KVM_CAP_ARM_RME to avoid conflicts.
Changes since v8:
 * Minor improvements to documentation following review.
 * Bump the magic numbers to avoid conflicts.
Changes since v7:
 * Add documentation of new ioctls
 * Bump the magic numbers to avoid conflicts
Changes since v6:
 * Rename some of the symbols to make their usage clearer and avoid
   repetition.
Changes from v5:
 * Actually expose the new VCPU capability (KVM_ARM_VCPU_REC) by bumping
   KVM_VCPU_MAX_FEATURES - note this also exposes KVM_ARM_VCPU_HAS_EL2!
---
 Documentation/virt/kvm/api.rst | 47 ++++++++++++++++++++++++++++++++++
 include/uapi/linux/kvm.h       | 13 ++++++++++
 2 files changed, 60 insertions(+)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 1de6fd5fc88c..ce588c05b26a 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -6642,6 +6642,44 @@ if the guest_memfd memory was pinned in IOMMU page tables.
 
 See also: :ref: `KVM_SET_MEMORY_ATTRIBUTES`.
 
+4.146 KVM_ARM_RMI_POPULATE
+--------------------------
+
+:Capability: KVM_CAP_ARM_RMI
+:Architectures: arm64
+:Type: vm ioctl
+:Parameters: struct kvm_arm_rmi_populate (in/out)
+:Returns: 0 on success, < 0 on error
+
+::
+
+  struct kvm_arm_rmi_populate {
+	__u64 base;
+	__u64 size;
+	__u64 source_uaddr;
+	__u32 flags;
+	__u32 reserved;
+  };
+
+Populate the guest address range described by `base` and `size` with data from
+the userspace buffer at `source_uaddr`. The guest_memfd range backing the
+memory must have `KVM_MEMORY_ATTRIBUTE_PRIVATE` set.
+
+Arm CCA cannot perform an in-place shared-to-private conversion while
+preserving memory contents. Therefore, `source_uaddr` must be a valid,
+page-aligned userspace pointer. The operation uses `RMI_RTT_DATA_MAP_INIT`,
+which also sets the region to `RIPAS_RAM`.
+
+This is only valid before any VCPUs have been run. The ioctl might not populate
+the entire region and in this case the kernel updates the fields `base`, `size`
+and `source_uaddr`. User space may have to repeatedly call it until `size` is 0
+to populate the entire region.
+
+`flags` can be set to `KVM_ARM_RMI_POPULATE_FLAGS_MEASURE` to request that the
+populated data is hashed and added to the guest's Realm Initial Measurement
+(RIM) stored by the RMM. This can then be retrieved by the guest (using the RSI
+interface) to present to an attestation server.
+
 .. _kvm_run:
 
 5. The kvm_run structure
@@ -9025,6 +9063,15 @@ enabled, cmma can't be enabled anymore and pfmfi and the storage key
 interpretation are disabled. If cmma has already been enabled or the
 hpage_2g module parameter is not set to 1, -EINVAL is returned.
 
+7.48 KVM_CAP_ARM_RMI
+--------------------
+
+:Architectures: arm64
+:Target: VM
+:Parameters: None
+
+This capability indicates that support for CCA realms is available.
+
 8. Other capabilities.
 ======================
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 129d6f630325..0231ff174a50 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -998,6 +998,7 @@ struct kvm_enable_cap {
 #define KVM_CAP_S390_VSIE_ESAMODE 248
 #define KVM_CAP_S390_HPAGE_2G 249
 #define KVM_CAP_GUEST_MEMFD_MEMORY_ATTRIBUTES 250
+#define KVM_CAP_ARM_RMI 251
 
 struct kvm_irq_routing_irqchip {
 	__u32 irqchip;
@@ -1686,4 +1687,16 @@ struct kvm_pre_fault_memory {
 	__u64 padding[5];
 };
 
+/* Available with KVM_CAP_ARM_RMI, only for VMs with KVM_VM_TYPE_ARM_REALM */
+#define KVM_ARM_RMI_POPULATE	_IOWR(KVMIO, 0xd7, struct kvm_arm_rmi_populate)
+#define KVM_ARM_RMI_POPULATE_FLAGS_MEASURE	(1 << 0)
+
+struct kvm_arm_rmi_populate {
+	__u64 base;
+	__u64 size;
+	__u64 source_uaddr;
+	__u32 flags;
+	__u32 reserved;
+};
+
 #endif /* __LINUX_KVM_H */
-- 
2.43.0

[PATCH v16 14/45] KVM: arm64: CCA: Add basic infrastructure for creating a realm

[Steven Price]

Introduce the skeleton functions for creating and destroying a realm.
The IPA size requested is checked against what the RMM supports.

The actual work of constructing the realm will be added in future
patches.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Remove realm->params and only temporarily allocate the page when the
   realm is being created.
Changes since v14:
 * Adapt to the RMM v2.0-bet2 realm parameter layout and SRO-based realm
   creation.
Changes since v13:
 * Rebased and updated to RMM-v2.0-bet1.
 * Auxiliary granules have been removed in RMM-v2.0-bet1
Changes since v12:
 * Drop the RMM_PAGE_{SHIFT,SIZE} defines - the RMM is now configured to
   be the same as the host's page size.
 * Rework delegate/undelegate functions to use the new RMI range based
   operations.
Changes since v11:
 * Major rework to drop the realm configuration and make the
   construction of realms implicit rather than driven by the VMM
   directly.
 * The code to create RDs, handle VMIDs etc is moved to later patches.
Changes since v10:
 * Rename from RME to RMI.
 * Move the stage2 cleanup to a later patch.
Changes since v9:
 * Avoid walking the stage 2 page tables when destroying the realm -
   the real ones are not accessible to the non-secure world, and the RMM
   may leave junk in the physical pages when returning them.
 * Fix an error path in realm_create_rd() to actually return an error value.
Changes since v8:
 * Fix free_delegated_granule() to not call kvm_account_pgtable_pages();
   a separate wrapper will be introduced in a later patch to deal with
   RTTs.
 * Minor code cleanups following review.
Changes since v7:
 * Minor code cleanup following Gavin's review.
Changes since v6:
 * Separate RMM RTT calculations from host PAGE_SIZE. This allows the
   host page size to be larger than 4k while still communicating with an
   RMM which uses 4k granules.
Changes since v5:
 * Introduce free_delegated_granule() to replace many
   undelegate/free_page() instances and centralise the comment on
   leaking when the undelegate fails.
 * Several other minor improvements suggested by reviews - thanks for
   the feedback!
Changes since v2:
 * Improved commit description.
 * Improved return failures for rmi_check_version().
 * Clear contents of PGD after it has been undelegated in case the RMM
   left stale data.
 * Minor changes to reflect changes in previous patches.
---
 arch/arm64/include/asm/kvm_emulate.h | 24 +++++++++++
 arch/arm64/include/asm/kvm_rmi.h     | 63 ++++++++++++++++++++++++++++
 arch/arm64/kvm/arm.c                 | 12 ++++++
 arch/arm64/kvm/mmu.c                 | 18 +++++++-
 arch/arm64/kvm/rmi.c                 | 56 +++++++++++++++++++++++++
 5 files changed, 171 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 5bf3d7e1d92c..e26d6755279f 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -688,4 +688,28 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu *vcpu)
 			vcpu->arch.hcrx_el2 |= HCRX_EL2_EnASR;
 	}
 }
+
+static inline bool kvm_is_realm(struct kvm *kvm)
+{
+	if (static_branch_unlikely(&kvm_rmi_is_available))
+		return kvm->arch.is_realm;
+	return false;
+}
+
+static inline enum realm_state kvm_realm_state(struct kvm *kvm)
+{
+	return READ_ONCE(kvm->arch.realm.state);
+}
+
+static inline void kvm_set_realm_state(struct kvm *kvm,
+				       enum realm_state new_state)
+{
+	WRITE_ONCE(kvm->arch.realm.state, new_state);
+}
+
+static inline bool kvm_realm_is_created(struct kvm *kvm)
+{
+	return kvm_is_realm(kvm) && kvm_realm_state(kvm) != REALM_STATE_NONE;
+}
+
 #endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 57d24b244c95..cefd00b76806 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -6,12 +6,75 @@
 #ifndef __ASM_KVM_RMI_H
 #define __ASM_KVM_RMI_H
 
+#include <linux/arm-smccc-rmi.h>
+
+/**
+ * enum realm_state - State of a Realm
+ *
+ * Mirrors the RMM's Realm lifecycle states where they are meaningful to KVM,
+ * with REALM_STATE_DYING being a KVM-internal state used to prevent further
+ * requests while teardown is in progress. KVM does not track REALM_SYSTEM_OFF
+ * or REALM_ZOMBIE separately as they naturally lead to teardown.
+ */
+enum realm_state {
+	/**
+	 * @REALM_STATE_NONE:
+	 *      Realm has not yet been created. rmi_realm_create() has not
+	 *      yet been called.
+	 */
+	REALM_STATE_NONE,
+	/**
+	 * @REALM_STATE_NEW:
+	 *      Realm is under construction, rmi_realm_create() has been
+	 *      called, but it is not yet activated. Pages may be populated.
+	 */
+	REALM_STATE_NEW,
+	/**
+	 * @REALM_STATE_ACTIVE:
+	 *      Realm has been created and is eligible for execution with
+	 *      rmi_rec_enter(). Pages may no longer be populated with
+	 *      rmi_data_create().
+	 */
+	REALM_STATE_ACTIVE,
+	/**
+	 * @REALM_STATE_DYING:
+	 *      Realm is in the process of being destroyed or has already been
+	 *      destroyed.
+	 */
+	REALM_STATE_DYING,
+	/**
+	 * @REALM_STATE_DEAD:
+	 *      Realm has been destroyed.
+	 */
+	REALM_STATE_DEAD
+};
+
 /**
  * struct realm - Additional per VM data for a Realm
+ *
+ * @rd: Kernel mapping of the RMM-managed Realm Descriptor (RD) granule
+ * @sro: Preallocated SRO state context for Realm MMU operations
+ * @state: The lifetime state machine for the realm
+ * @ia_bits: Number of valid Input Address bits in the IPA
  */
 struct realm {
+	void *rd;
+	/*
+	 * Reused by RTT map/unmap SRO commands. Those commands are only
+	 * issued from Realm stage-2 map/unmap paths while kvm->mmu_lock is
+	 * held for write, including Realm fault handling where
+	 * kvm_fault_lock() takes the write side, so concurrent use is
+	 * serialized.
+	 */
+	struct rmi_sro_state *sro;
+	enum realm_state state;
+	unsigned int ia_bits;
 };
 
 void kvm_init_rmi(void);
+u32 kvm_rmm_ipa_limit(void);
+
+int kvm_init_realm(struct kvm *kvm);
+void kvm_destroy_realm(struct kvm *kvm);
 
 #endif /* __ASM_KVM_RMI_H */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index b961c22fce3d..c4d906861736 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -266,6 +266,13 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 
 	bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES);
 
+	/* Initialise the realm bits after the generic bits are enabled */
+	if (kvm_is_realm(kvm)) {
+		ret = kvm_init_realm(kvm);
+		if (ret)
+			goto err_uninit_mmu;
+	}
+
 	return 0;
 
 err_uninit_mmu:
@@ -328,6 +335,8 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_unshare_hyp(kvm, kvm + 1);
 
 	kvm_arm_teardown_hypercalls(kvm);
+	if (kvm_is_realm(kvm))
+		kvm_destroy_realm(kvm);
 }
 
 static bool kvm_has_full_ptr_auth(void)
@@ -488,6 +497,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 		else
 			r = kvm_supports_cacheable_pfnmap();
 		break;
+	case KVM_CAP_ARM_RMI:
+		r = static_key_enabled(&kvm_rmi_is_available);
+		break;
 
 	default:
 		r = 0;
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 6c941aaa10c6..8b9efa8a3539 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -904,10 +904,14 @@ static struct kvm_pgtable_mm_ops kvm_s2_mm_ops = {
 
 static int kvm_init_ipa_range(struct kvm_s2_mmu *mmu, unsigned long type)
 {
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
 	u32 kvm_ipa_limit = get_kvm_ipa_limit();
 	u64 mmfr0, mmfr1;
 	u32 phys_shift;
 
+	if (kvm_is_realm(kvm))
+		kvm_ipa_limit = kvm_rmm_ipa_limit();
+
 	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
 	if (is_protected_kvm_enabled()) {
 		phys_shift = kvm_ipa_limit;
@@ -957,9 +961,18 @@ static void stage2_destroy_range(struct kvm_pgtable *pgt, phys_addr_t addr,
 
 static void kvm_stage2_destroy(struct kvm_pgtable *pgt)
 {
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(pgt->mmu);
 	unsigned int ia_bits = VTCR_EL2_IPA(pgt->mmu->vtcr);
 
-	stage2_destroy_range(pgt, 0, BIT(ia_bits));
+	/*
+	 * Realm RTTs are inaccessible to the host and may contain stale data
+	 * after the RMM has released them. The non-root RTTs are explicitly
+	 * destroyed through RMI before the RD is destroyed; only the root PGD
+	 * pages remain to be freed here.
+	 */
+	if (!kvm_is_realm(kvm))
+		stage2_destroy_range(pgt, 0, BIT(ia_bits));
+
 	KVM_PGT_FN(kvm_pgtable_stage2_destroy_pgd)(pgt);
 }
 
@@ -1001,6 +1014,8 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 		return -EINVAL;
 	}
 
+	mmu->arch = &kvm->arch;
+
 	err = kvm_init_ipa_range(mmu, type);
 	if (err)
 		return err;
@@ -1009,7 +1024,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 	if (!pgt)
 		return -ENOMEM;
 
-	mmu->arch = &kvm->arch;
 	err = KVM_PGT_FN(kvm_pgtable_stage2_init)(pgt, mmu, &kvm_s2_mm_ops);
 	if (err)
 		goto out_free_pgtable;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 247c4f033945..528b01d5d71d 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -5,6 +5,8 @@
 
 #include <linux/kvm_host.h>
 
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_mmu.h>
 #include <asm/kvm_pgtable.h>
 #include <asm/rmi_cmds.h>
 #include <asm/virt.h>
@@ -14,6 +16,60 @@ static bool rmi_has_feature(int reg, unsigned long feature)
 	return !!u64_get_bits(rmi_feat_reg(reg), feature);
 }
 
+u32 kvm_rmm_ipa_limit(void)
+{
+	return u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_S2SZ);
+}
+
+void kvm_destroy_realm(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+	size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr);
+
+	if (!kvm_realm_is_created(kvm)) {
+		kfree(realm->sro);
+		realm->sro = NULL;
+		return;
+	}
+
+	kvm_set_realm_state(kvm, REALM_STATE_DYING);
+
+	if (realm->rd) {
+		phys_addr_t rd_phys = virt_to_phys(realm->rd);
+
+		if (WARN_ON(rmi_realm_terminate(rd_phys, realm->sro)))
+			return;
+
+		if (WARN_ON(rmi_realm_destroy(rd_phys, realm->sro)))
+			return;
+		free_delegated_page(rd_phys);
+		realm->rd = NULL;
+	}
+
+	if (WARN_ON(rmi_undelegate_range(kvm->arch.mmu.pgd_phys,
+					 pgd_size)))
+		return;
+
+	kvm_set_realm_state(kvm, REALM_STATE_DEAD);
+
+	/* Now that the realm is destroyed, free the entry-level RTTs. */
+	kvm_free_stage2_pgd(&kvm->arch.mmu);
+
+	kfree(realm->sro);
+	realm->sro = NULL;
+}
+
+int kvm_init_realm(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+
+	realm->sro = kmalloc_obj(*realm->sro);
+	if (!realm->sro)
+		return -ENOMEM;
+
+	return 0;
+}
+
 static int rmm_check_features(void)
 {
 	if (kvm_lpa2_is_enabled() &&
-- 
2.43.0

[PATCH v16 15/45] KVM: arm64: CCA: Don't expose unsupported capabilities for realm guests

[Steven Price]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

RMM v2.0 provides no mechanism for the host to perform debug operations
on the guest. So limit the extensions that are visible to an allowlist
so that only those capabilities we can support are advertised.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v13:
 * Add missing check in kvm_vm_ioctl_enable_cap().
Changes since v10:
 * Add a kvm_realm_ext_allowed() function which limits which extensions
   are exposed to an allowlist. This removes the need for special casing
   various extensions.
Changes since v7:
 * Remove the helper functions and inline the kvm_is_realm() check with
   a ternary operator.
 * Rewrite the commit message to explain this patch.
---
 arch/arm64/kvm/arm.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index c4d906861736..6f39831dcf5d 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -135,6 +135,26 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
+static bool kvm_realm_ext_allowed(long ext)
+{
+	switch (ext) {
+	case KVM_CAP_IRQCHIP:
+	case KVM_CAP_ARM_PSCI:
+	case KVM_CAP_ARM_PSCI_0_2:
+	case KVM_CAP_NR_VCPUS:
+	case KVM_CAP_MAX_VCPUS:
+	case KVM_CAP_MAX_VCPU_ID:
+	case KVM_CAP_MSI_DEVID:
+	case KVM_CAP_ARM_VM_IPA_SIZE:
+	case KVM_CAP_ARM_PTRAUTH_ADDRESS:
+	case KVM_CAP_ARM_PTRAUTH_GENERIC:
+	case KVM_CAP_ARM_RMI:
+	case KVM_CAP_SYNC_MMU:
+		return true;
+	}
+	return false;
+}
+
 int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 			    struct kvm_enable_cap *cap)
 {
@@ -146,6 +166,9 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 	if (is_protected_kvm_enabled() && !kvm_pkvm_ext_allowed(kvm, cap->cap))
 		return -EINVAL;
 
+	if (kvm && kvm_is_realm(kvm) && !kvm_realm_ext_allowed(cap->cap))
+		return -EINVAL;
+
 	switch (cap->cap) {
 	case KVM_CAP_ARM_NISV_TO_USER:
 		r = 0;
@@ -380,6 +403,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	if (is_protected_kvm_enabled() && !kvm_pkvm_ext_allowed(kvm, ext))
 		return 0;
 
+	if (kvm && kvm_is_realm(kvm) && !kvm_realm_ext_allowed(ext))
+		return 0;
+
 	switch (ext) {
 	case KVM_CAP_IRQCHIP:
 		r = vgic_present;
-- 
2.43.0

[PATCH v16 16/45] KVM: arm64: CCA: Allow passing the machine type in KVM creation

[Steven Price]

Previously machine type was used purely for specifying the physical
address size of the guest. Reserve the higher bits to specify an ARM
specific machine type and declare a new type 'KVM_VM_TYPE_ARM_REALM'
used to create a realm guest.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Specify the encoding for each VM type in the documentation.
Changes since v13:
 * Rework to use the two top bits for the machine type now that pKVM has
   merged and used the top bit for KVM_VM_TYPE_ARM_PROTECTED.
 * Update the documentation to include KVM_VM_TYPE_ARM_PROTECTED as
   well.
Changes since v9:
 * Explictly set realm.state to REALM_STATE_NONE rather than rely on the
   zeroing of the structure.
Changes since v7:
 * Add some documentation explaining the new machine type.
Changes since v6:
 * Make the check for kvm_rme_is_available more visible and report an
   error code of -EPERM (instead of -EINVAL) to make it explicit that
   the kernel supports RME, but the platform doesn't.
---
 Documentation/virt/kvm/api.rst | 21 +++++++++++++++++++--
 arch/arm64/kvm/arm.c           | 11 +++++++++++
 include/uapi/linux/kvm.h       |  7 ++++++-
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index ce588c05b26a..802601eaf560 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -181,8 +181,25 @@ flag KVM_VM_MIPS_VZ.
 ARM64:
 ^^^^^^
 
-On arm64, the physical address size for a VM (IPA Size limit) is limited
-to 40bits by default. The limit can be configured if the host supports the
+On arm64, the machine type identifier is used to encode a type and the
+physical address size for the VM. The lower byte (bits[7:0]) encodes the
+address size and the upper bits[31:30] encode a machine type. The machine
+types that might be available are:
+
+ =========================   =======   ========================================
+ Type                        [31:30]   Description
+ =========================   =======   ========================================
+ KVM_VM_TYPE_ARM_NORMAL      0b00      A standard VM
+ KVM_VM_TYPE_ARM_REALM       0b01      A "realm" VM using the Arm Confidential
+                                       Compute extensions, the VM's memory is
+                                       protected from the host.
+ KVM_VM_TYPE_ARM_PROTECTED   0b10      A "protected" VM using pKVM to
+                                       isolate the VM from the host.
+ Reserved                    0b11      Reserved for future use
+ =========================   =======   ========================================
+
+The physical address size for a VM (IPA Size limit) is limited to 40bits
+by default. The limit can be configured if the host supports the
 extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use
 KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type
 identifier, where IPA_Bits is the maximum width of any physical
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6f39831dcf5d..9881fd6c511c 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -249,6 +249,17 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 	mutex_unlock(&kvm->lock);
 #endif
 
+	if ((type & KVM_VM_TYPE_ARM_PROTECTED) &&
+	    (type & KVM_VM_TYPE_ARM_REALM))
+		return -EINVAL;
+
+	if (type & KVM_VM_TYPE_ARM_REALM) {
+		if (!static_branch_unlikely(&kvm_rmi_is_available))
+			return -EINVAL;
+		kvm_set_realm_state(kvm, REALM_STATE_NONE);
+		kvm->arch.is_realm = true;
+	}
+
 	kvm_init_nested(kvm);
 
 	ret = kvm_share_hyp(kvm, kvm + 1);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 0231ff174a50..adee3936d6ae 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -700,14 +700,19 @@ struct kvm_enable_cap {
  * address size for the VM. Bits[7-0] are reserved for the guest
  * PA size shift (i.e, log2(PA_Size)). For backward compatibility,
  * value 0 implies the default IPA size, 40bits.
+ *
+ * Bits[30-31] are reserved for the VM type
  */
 #define KVM_VM_TYPE_ARM_IPA_SIZE_MASK	0xffULL
 #define KVM_VM_TYPE_ARM_IPA_SIZE(x)		\
 	((x) & KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
 
+#define KVM_VM_TYPE_ARM_NORMAL		0
+#define KVM_VM_TYPE_ARM_REALM		(1UL << 30)
 #define KVM_VM_TYPE_ARM_PROTECTED	(1UL << 31)
 #define KVM_VM_TYPE_ARM_MASK		(KVM_VM_TYPE_ARM_IPA_SIZE_MASK | \
-					 KVM_VM_TYPE_ARM_PROTECTED)
+					 KVM_VM_TYPE_ARM_PROTECTED | \
+					 KVM_VM_TYPE_ARM_REALM)
 
 /*
  * ioctls for /dev/kvm fds:
-- 
2.43.0

[PATCH v16 17/45] KVM: arm64: CCA: Tear down RTTs

[Steven Price]

The RMM owns the stage 2 page tables for a realm, and KVM must request
that the RMM creates/destroys entries as necessary. The physical pages
to store the page tables are delegated to the realm as required, and can
be undelegated when no longer used.

Creating new RTTs is the easy part, tearing down is a little more
tricky. The result of realm_rtt_destroy() can be used to effectively
walk the tree and destroy the entries (undelegating pages that were
given to the realm).

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Propagate negative error codes.
Changes since v14:
 * Teardown is now serialized under config_lock and idempotent.
Changes since v13:
 * Avoid the double call of kvm_free_stage2_pgd() by splitting the work
   across that and a new function kvm_realm_uninit_stage2() which is
   only called for realm guests.
Changes since v12:
 * Simplify some functions now we know RMM page size is the same as the
   host's.
Changes since v11:
 * Moved some code from earlier in the series to this one so that it's
   added when it's first used.
Changes since v10:
 * RME->RMI rename.
 * Some code to handle freeing stage 2 PGD moved into this patch where
   it belongs.
Changes since v9:
 * Add a comment clarifying that root level RTTs are not destroyed until
   after the RD is destroyed.
Changes since v8:
 * Introduce free_rtt() wrapper which calls free_delegated_granule()
   followed by kvm_account_pgtable_pages(). This makes it clear where an
   RTT is being freed rather than just a delegated granule.
Changes since v6:
 * Move rme_rtt_level_mapsize() and supporting defines from kvm_rme.h
   into rme.c as they are only used in that file.
Changes since v5:
 * Rename some RME_xxx defines to do with page sizes as RMM_xxx - they are
   a property of the RMM specification not the RME architecture.
Changes since v2:
 * Moved {alloc,free}_delegated_page() and ensure_spare_page() to a
   later patch when they are actually used.
 * Some simplifications now rmi_xxx() functions allow NULL as an output
   parameter.
 * Improved comments and code layout.
---
 arch/arm64/include/asm/kvm_rmi.h |  11 ++
 arch/arm64/kvm/mmu.c             |  17 ++-
 arch/arm64/kvm/rmi.c             | 198 +++++++++++++++++++++++++++++++
 3 files changed, 225 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index cefd00b76806..339a9f8c4408 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -56,6 +56,8 @@ enum realm_state {
  * @sro: Preallocated SRO state context for Realm MMU operations
  * @state: The lifetime state machine for the realm
  * @ia_bits: Number of valid Input Address bits in the IPA
+ * @stage2_unmapped: The Realm stage-2 mappings have been removed
+ * @rtts_destroyed: The non-root RTTs have been torn down
  */
 struct realm {
 	void *rd;
@@ -69,6 +71,8 @@ struct realm {
 	struct rmi_sro_state *sro;
 	enum realm_state state;
 	unsigned int ia_bits;
+	bool stage2_unmapped;
+	bool rtts_destroyed;
 };
 
 void kvm_init_rmi(void);
@@ -76,5 +80,12 @@ u32 kvm_rmm_ipa_limit(void);
 
 int kvm_init_realm(struct kvm *kvm);
 void kvm_destroy_realm(struct kvm *kvm);
+int kvm_realm_teardown_stage2(struct kvm *kvm);
+
+static inline bool kvm_realm_is_private_address(struct realm *realm,
+						unsigned long addr)
+{
+	return !(addr & BIT(realm->ia_bits - 1));
+}
 
 #endif /* __ASM_KVM_RMI_H */
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 8b9efa8a3539..cd06881c1497 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1060,9 +1060,24 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long t
 	return err;
 }
 
+static void kvm_realm_uninit_stage2(struct kvm_s2_mmu *mmu)
+{
+	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
+
+	mutex_lock(&kvm->arch.config_lock);
+	if (kvm_realm_state(kvm) == REALM_STATE_ACTIVE) {
+		kvm_set_realm_state(kvm, REALM_STATE_DYING);
+		WARN_ON(kvm_realm_teardown_stage2(kvm));
+	}
+	mutex_unlock(&kvm->arch.config_lock);
+}
+
 void kvm_uninit_stage2_mmu(struct kvm *kvm)
 {
-	kvm_free_stage2_pgd(&kvm->arch.mmu);
+	if (kvm_is_realm(kvm))
+		kvm_realm_uninit_stage2(&kvm->arch.mmu);
+	else
+		kvm_free_stage2_pgd(&kvm->arch.mmu);
 	kvm_mmu_free_memory_cache(&kvm->arch.mmu.split_page_cache);
 }
 
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 528b01d5d71d..4154c6cc1112 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -11,6 +11,14 @@
 #include <asm/rmi_cmds.h>
 #include <asm/virt.h>
 
+static inline unsigned long rmi_rtt_level_mapsize(int level)
+{
+	if (WARN_ON(level > KVM_PGTABLE_LAST_LEVEL))
+		return PAGE_SIZE;
+
+	return (1UL << ARM64_HW_PGTABLE_LEVEL_SHIFT(level));
+}
+
 static bool rmi_has_feature(int reg, unsigned long feature)
 {
 	return !!u64_get_bits(rmi_feat_reg(reg), feature);
@@ -21,11 +29,189 @@ u32 kvm_rmm_ipa_limit(void)
 	return u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_S2SZ);
 }
 
+static int get_start_level(struct realm *realm)
+{
+	return 4 - stage2_pgtable_levels(realm->ia_bits);
+}
+
+static void free_rtt(phys_addr_t phys)
+{
+	if (free_delegated_page(phys))
+		return;
+
+	kvm_account_pgtable_pages(phys_to_virt(phys), -1);
+}
+
+/*
+ * realm_rtt_destroy - Destroy an RTT at @level for @addr.
+ *
+ * Returns - Result of the RMI_RTT_DESTROY call, and:
+ * @rtt_granule:	RTT granule, if the RTT was destroyed.
+ * @next_addr:		IPA corresponding to the next possible valid entry we
+ *			can target
+ */
+static long realm_rtt_destroy(struct realm *realm, unsigned long addr,
+			      int level, phys_addr_t *rtt_granule,
+			      unsigned long *next_addr)
+{
+	unsigned long out_rtt;
+	long ret;
+
+	ret = rmi_rtt_destroy(virt_to_phys(realm->rd), addr, level,
+			      &out_rtt, next_addr);
+
+	*rtt_granule = out_rtt;
+
+	return ret;
+}
+
+static int realm_tear_down_rtt_level(struct realm *realm, int level,
+				     unsigned long start, unsigned long end)
+{
+	ssize_t map_size;
+	unsigned long addr, next_addr;
+
+	if (WARN_ON(level > KVM_PGTABLE_LAST_LEVEL))
+		return -EINVAL;
+
+	map_size = rmi_rtt_level_mapsize(level - 1);
+
+	for (addr = start; addr < end; addr = next_addr) {
+		phys_addr_t rtt_granule;
+		long ret;
+		unsigned long align_addr = ALIGN(addr, map_size);
+
+		next_addr = ALIGN(addr + 1, map_size);
+
+		if (next_addr > end || align_addr != addr) {
+			/*
+			 * The target range is smaller than what this level
+			 * covers, recurse deeper.
+			 */
+			ret = realm_tear_down_rtt_level(realm,
+							level + 1,
+							addr,
+							min(next_addr, end));
+			if (ret)
+				return ret;
+			continue;
+		}
+
+		ret = realm_rtt_destroy(realm, addr, level,
+					&rtt_granule, &next_addr);
+		if (ret < 0)
+			return ret;
+
+		switch (RMI_RETURN_STATUS(ret)) {
+		case RMI_SUCCESS:
+			free_rtt(rtt_granule);
+			break;
+		case RMI_ERROR_RTT:
+			if (next_addr > addr) {
+				/* Missing RTT, skip */
+				break;
+			}
+			/*
+			 * We tear down the RTT range for the full IPA
+			 * space, after everything is unmapped. Also we
+			 * descend down only if we cannot tear down a
+			 * top level RTT. Thus RMM must be able to walk
+			 * to the requested level. e.g., a block mapping
+			 * exists at L1 or L2.
+			 */
+			if (WARN_ON(RMI_RETURN_INDEX(ret) != level))
+				return -EBUSY;
+			if (WARN_ON(level == KVM_PGTABLE_LAST_LEVEL))
+				return -EBUSY;
+
+			/*
+			 * The table has active entries in it, recurse deeper
+			 * and tear down the RTTs.
+			 */
+			next_addr = ALIGN(addr + 1, map_size);
+			ret = realm_tear_down_rtt_level(realm,
+							level + 1,
+							addr,
+							next_addr);
+			if (ret)
+				return ret;
+			/*
+			 * Now that the child RTTs are destroyed,
+			 * retry at this level.
+			 */
+			next_addr = addr;
+			break;
+		default:
+			WARN_ON(1);
+			return -ENXIO;
+		}
+	}
+
+	return 0;
+}
+
+static int realm_tear_down_rtt_range(struct realm *realm,
+				     unsigned long start, unsigned long end)
+{
+	/*
+	 * Root level RTTs can only be destroyed after the RD is destroyed. So
+	 * tear down everything below the root level
+	 */
+	return realm_tear_down_rtt_level(realm, get_start_level(realm) + 1,
+					 start, end);
+}
+
+static int realm_destroy_rtts(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+	unsigned int ia_bits = realm->ia_bits;
+	int ret;
+
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	if (realm->rtts_destroyed)
+		return 0;
+
+	ret = realm_tear_down_rtt_range(realm, 0, (1UL << ia_bits));
+	if (ret)
+		return ret;
+
+	realm->rtts_destroyed = true;
+	return 0;
+}
+
+static void realm_unmap_stage2(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	if (realm->stage2_unmapped)
+		return;
+
+	write_lock(&kvm->mmu_lock);
+	kvm_stage2_unmap_range(&kvm->arch.mmu, 0,
+			       BIT(realm->ia_bits - 1), true);
+	write_unlock(&kvm->mmu_lock);
+
+	realm->stage2_unmapped = true;
+}
+
+int kvm_realm_teardown_stage2(struct kvm *kvm)
+{
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	realm_unmap_stage2(kvm);
+	return realm_destroy_rtts(kvm);
+}
+
 void kvm_destroy_realm(struct kvm *kvm)
 {
 	struct realm *realm = &kvm->arch.realm;
 	size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr);
 
+	guard(mutex)(&kvm->arch.config_lock);
+
 	if (!kvm_realm_is_created(kvm)) {
 		kfree(realm->sro);
 		realm->sro = NULL;
@@ -34,12 +220,24 @@ void kvm_destroy_realm(struct kvm *kvm)
 
 	kvm_set_realm_state(kvm, REALM_STATE_DYING);
 
+	/*
+	 * REALM_DESTROY requires the realm to be non-live: all RECs must have
+	 * been destroyed and the root RTTs must be empty. Unmap the IPA space
+	 * and destroy any non-root RTTs before tearing down the RD. The root
+	 * RTT pages are still owned by the RMM at this point, so keep the KVM
+	 * pgtable alive until after REALM_DESTROY and undelegation.
+	 */
+	realm_unmap_stage2(kvm);
+
 	if (realm->rd) {
 		phys_addr_t rd_phys = virt_to_phys(realm->rd);
 
 		if (WARN_ON(rmi_realm_terminate(rd_phys, realm->sro)))
 			return;
 
+		if (WARN_ON(realm_destroy_rtts(kvm)))
+			return;
+
 		if (WARN_ON(rmi_realm_destroy(rd_phys, realm->sro)))
 			return;
 		free_delegated_page(rd_phys);
-- 
2.43.0

[PATCH v16 18/45] KVM: arm64: CCA: Allocate and free RECs to match vCPUs

[Steven Price]

The RMM maintains a data structure known as the Realm Execution Context
(or REC). It is similar to struct kvm_vcpu and tracks the state of the
virtual CPUs. KVM must delegate memory and request the structures are
created when vCPUs are created, and suitably tear down on destruction.

RECs may require additional pages (e.g. for storing larger register
state for SVE). The RMM can request extra pages for this purpose using
the Stateful RMI Operations (SRO) functionality to request pages during
REC creation. These pages are then passed back to the host from the RMM
('reclaimed') when the REC is destroyed. The kernel tracking object
(struct rmi_sro_state) is stored in the realm_rec structure to avoid
memory allocation during the destruction path.

Note that only some of register state for the REC can be set by KVM, the
rest is defined by the RMM (zeroed). The register state then cannot be
changed by KVM after the REC is created (except when the guest
explicitly requests this e.g. by performing a PSCI call).

Note that the function kvm_create_rec() is unused at this point, a
future patch will add the call and remove the __maybe_unused attribute.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Propagate negative error code in kvm_create_rec().
Changes since v14:
 * Handle partial REC creation better by NULLing rec->run, rec->rec_page
   and rec->sro when freeing.
Changes since v13:
 * Support SRO for REC creation/destruction instead of auxiliary
   granules.
Changes since v12:
 * Use the new range-based delegation RMI.
Changes since v11:
 * Remove the KVM_ARM_VCPU_REC feature. User space no longer needs to
   configure each VCPU separately, RECs are created on the first VCPU
   run of the guest.
Changes since v9:
 * Size the aux_pages array according to the PAGE_SIZE of the host.
Changes since v7:
 * Add comment explaining the aux_pages array.
 * Rename "undeleted_failed" variable to "should_free" to avoid a
   confusing double negative.
Changes since v6:
 * Avoid reporting the KVM_ARM_VCPU_REC feature if the guest isn't a
   realm guest.
 * Support host page size being larger than RMM's granule size when
   allocating/freeing aux granules.
Changes since v5:
 * Separate the concept of vcpu_is_rec() and
   kvm_arm_vcpu_rec_finalized() by using the KVM_ARM_VCPU_REC feature as
   the indication that the VCPU is a REC.
Changes since v2:
 * Free rec->run earlier in kvm_destroy_realm() and adapt to previous patches.
---
 arch/arm64/include/asm/kvm_emulate.h |   5 ++
 arch/arm64/include/asm/kvm_host.h    |   3 +
 arch/arm64/include/asm/kvm_rmi.h     |  20 ++++++
 arch/arm64/kvm/arm.c                 |   6 ++
 arch/arm64/kvm/reset.c               |   1 +
 arch/arm64/kvm/rmi.c                 | 103 +++++++++++++++++++++++++++
 6 files changed, 138 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index e26d6755279f..2e69fe494716 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -712,4 +712,9 @@ static inline bool kvm_realm_is_created(struct kvm *kvm)
 	return kvm_is_realm(kvm) && kvm_realm_state(kvm) != REALM_STATE_NONE;
 }
 
+static inline bool vcpu_is_rec(const struct kvm_vcpu *vcpu)
+{
+	return kvm_is_realm(vcpu->kvm);
+}
+
 #endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 1a5e15040111..9b46b39ed11e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -949,6 +949,9 @@ struct kvm_vcpu_arch {
 
 	/* Hyp-readable copy of kvm_vcpu::pid */
 	pid_t pid;
+
+	/* Realm meta data */
+	struct realm_rec rec;
 };
 
 /*
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 339a9f8c4408..3bffd021ca26 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -75,12 +75,32 @@ struct realm {
 	bool rtts_destroyed;
 };
 
+/**
+ * struct realm_rec - Additional per VCPU data for a Realm
+ *
+ * @mpidr: MPIDR (Multiprocessor Affinity Register) value to identify this VCPU
+ * @rec_page: Kernel VA of the RMM's private page for this REC
+ * @rec_phys: Physical address of @rec_page
+ * @run: Kernel VA of the RmiRecRun structure shared with the RMM
+ * @run_phys: Physical address of @run
+ * @sro: A preallocated SRO state context
+ */
+struct realm_rec {
+	unsigned long mpidr;
+	void *rec_page;
+	phys_addr_t rec_phys;
+	struct rec_run *run;
+	phys_addr_t run_phys;
+	struct rmi_sro_state *sro;
+};
+
 void kvm_init_rmi(void);
 u32 kvm_rmm_ipa_limit(void);
 
 int kvm_init_realm(struct kvm *kvm);
 void kvm_destroy_realm(struct kvm *kvm);
 int kvm_realm_teardown_stage2(struct kvm *kvm);
+void kvm_destroy_rec(struct kvm_vcpu *vcpu);
 
 static inline bool kvm_realm_is_private_address(struct realm *realm,
 						unsigned long addr)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9881fd6c511c..38fac98cd6a4 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -589,6 +589,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 	/* Force users to call KVM_ARM_VCPU_INIT */
 	vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
 
+	vcpu->arch.rec.mpidr = INVALID_HWID;
+
 	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
 
 	/* Set up the timer */
@@ -1668,6 +1670,10 @@ static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
 	if (test_bit(KVM_ARM_VCPU_HAS_EL2, &features))
 		return -EINVAL;
 
+	/* Realms are incompatible with AArch32 */
+	if (vcpu_is_rec(vcpu))
+		return -EINVAL;
+
 	return 0;
 }
 
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index b963fd975aac..c18cdca7d125 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -161,6 +161,7 @@ void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
 	free_page((unsigned long)vcpu->arch.ctxt.vncr_array);
 	kfree(vcpu->arch.vncr_tlb);
 	kfree(vcpu->arch.ccsidr);
+	kvm_destroy_rec(vcpu);
 }
 
 static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 4154c6cc1112..f6686287119d 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -205,6 +205,109 @@ int kvm_realm_teardown_stage2(struct kvm *kvm)
 	return realm_destroy_rtts(kvm);
 }
 
+static int __maybe_unused kvm_create_rec(struct kvm_vcpu *vcpu)
+{
+	struct user_pt_regs *vcpu_regs = vcpu_gp_regs(vcpu);
+	unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
+	struct realm *realm = &vcpu->kvm->arch.realm;
+	struct realm_rec *rec = &vcpu->arch.rec;
+	struct rec_params *params;
+	long rmi_ret;
+	int r, i;
+
+	if (rec->run)
+		return -EBUSY;
+
+	/*
+	 * The RMM will report PSCI v1.0 to Realms and the KVM_ARM_VCPU_PSCI_0_2
+	 * flag covers v0.2 and onwards.
+	 */
+	if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_PSCI_0_2))
+		return -EINVAL;
+
+	BUILD_BUG_ON(sizeof(*params) > PAGE_SIZE);
+	BUILD_BUG_ON(sizeof(*rec->run) > PAGE_SIZE);
+
+	params = (struct rec_params *)get_zeroed_page(GFP_KERNEL);
+	rec->rec_page = (void *)__get_free_page(GFP_KERNEL);
+	rec->run = (struct rec_run *)get_zeroed_page(GFP_KERNEL);
+	rec->sro = kmalloc_obj(*rec->sro);
+	if (!params || !rec->rec_page || !rec->run || !rec->sro) {
+		r = -ENOMEM;
+		goto out_free_pages;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(params->gprs); i++)
+		params->gprs[i] = vcpu_regs->regs[i];
+
+	params->pc = vcpu_regs->pc;
+
+	if (vcpu->vcpu_id == 0)
+		params->flags |= REC_PARAMS_FLAG_RUNNABLE;
+
+	rec->rec_phys = virt_to_phys(rec->rec_page);
+	rec->run_phys = virt_to_phys(rec->run);
+
+	if (rmi_delegate_page(rec->rec_phys)) {
+		r = -ENXIO;
+		goto out_free_pages;
+	}
+
+	params->mpidr = mpidr;
+
+	rmi_ret = rmi_rec_create(virt_to_phys(realm->rd), rec->rec_phys,
+				 virt_to_phys(params), rec->sro);
+	if (rmi_ret) {
+		r = rmi_ret < 0 ? rmi_ret : -ENXIO;
+		goto out_undelegate_rmm_rec;
+	}
+
+	rec->mpidr = mpidr;
+
+	free_page((unsigned long)params);
+	return 0;
+
+out_undelegate_rmm_rec:
+	if (WARN_ON(rmi_undelegate_page(rec->rec_phys)))
+		rec->rec_page = NULL;
+out_free_pages:
+	free_page((unsigned long)rec->run);
+	free_page((unsigned long)rec->rec_page);
+	free_page((unsigned long)params);
+	kfree(rec->sro);
+	rec->run = NULL;
+	rec->rec_page = NULL;
+	rec->rec_phys = 0;
+	rec->run_phys = 0;
+	rec->sro = NULL;
+	return r;
+}
+
+void kvm_destroy_rec(struct kvm_vcpu *vcpu)
+{
+	struct realm_rec *rec = &vcpu->arch.rec;
+
+	if (!vcpu_is_rec(vcpu))
+		return;
+
+	if (!rec->run) {
+		/* Nothing to do if the VCPU hasn't been finalized */
+		return;
+	}
+
+	if (WARN_ON(rmi_rec_destroy(rec->rec_phys, rec->sro)))
+		return;
+
+	free_page((unsigned long)rec->run);
+	kfree(rec->sro);
+	free_delegated_page(rec->rec_phys);
+	rec->run = NULL;
+	rec->sro = NULL;
+	rec->rec_page = NULL;
+	rec->rec_phys = 0;
+	rec->run_phys = 0;
+}
+
 void kvm_destroy_realm(struct kvm *kvm)
 {
 	struct realm *realm = &kvm->arch.realm;
-- 
2.43.0

[PATCH v16 19/45] KVM: arm64: CCA: Support the VGIC in realms

[Steven Price]

The RMM provides emulation of a VGIC to the realm guest. With RMM v2.0
the registers are passed in the system registers so this works similar
to a normal guest, but kvm_arch_vcpu_put() need reordering to early out,
and realm guests don't support GICv2 even if the host does.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes from v12:
 * GIC registers are now passed in the system registers rather than via
   rec_entry/rec_exit which removes most of the changes.
Changes from v11:
 * Minor changes to align with the previous patches. Note that the VGIC
   handling will change with RMM v2.0.
Changes from v10:
 * Make sure we sync the VGIC v4 state, and only populate valid lrs from
   the list.
Changes from v9:
 * Copy gicv3_vmcr from the RMM at the same time as gicv3_hcr rather
   than having to handle that as a special case.
Changes from v8:
 * Propagate gicv3_hcr to from the RMM.
Changes from v5:
 * Handle RMM providing fewer GIC LRs than the hardware supports.
---
 arch/arm64/kvm/arm.c            | 11 ++++++++---
 arch/arm64/kvm/vgic/vgic-init.c |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 38fac98cd6a4..2959a1451232 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -791,19 +791,24 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 		kvm_call_hyp_nvhe(__pkvm_vcpu_put);
 	}
 
+	kvm_timer_vcpu_put(vcpu);
+	kvm_vgic_put(vcpu);
 	kvm_vcpu_put_debug(vcpu);
+
+	vcpu->cpu = -1;
+
+	if (vcpu_is_rec(vcpu))
+		return;
+
 	kvm_arch_vcpu_put_fp(vcpu);
 	if (has_vhe())
 		kvm_vcpu_put_vhe(vcpu);
-	kvm_timer_vcpu_put(vcpu);
-	kvm_vgic_put(vcpu);
 	kvm_vcpu_pmu_restore_host(vcpu);
 	if (vcpu_has_nv(vcpu))
 		kvm_vcpu_put_hw_mmu(vcpu);
 	kvm_arm_vmid_clear_active();
 
 	vcpu_clear_on_unsupported_cpu(vcpu);
-	vcpu->cpu = -1;
 }
 
 static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 907057881b26..fd77db35ef02 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -81,7 +81,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	 * the proper checks already.
 	 */
 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
-		!kvm_vgic_global_state.can_emulate_gicv2)
+	    (!kvm_vgic_global_state.can_emulate_gicv2 || kvm_is_realm(kvm)))
 		return -ENODEV;
 
 	/*
-- 
2.43.0

[PATCH v16 20/45] KVM: arm64: CCA: Support timers in realm RECs

[Steven Price]

The RMM keeps track of the timer while the realm REC is running, but on
exit to the normal world KVM is responsible for handling the timers.

A later patch adds the support for propagating the timer values from the
exit data structure and calling kvm_realm_timers_update().

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Major rewrite to make better use of the KVM infrastructure.
Changes since v14:
 * Special case in kvm_timer_vcpu_load()/kvm_timer_vcpu_put() the timer
   handling.
Changes since v12:
 * Adapt to upstream changes.
Changes since v11:
 * Drop the kvm_is_realm() check from timer_set_offset(). We already
   ensure that the offset is 0 when calling the function.
Changes since v10:
 * KVM_CAP_COUNTER_OFFSET is now already hidden by a previous patch.
Changes since v9:
 * No need to move the call to kvm_timer_unblocking() in
   kvm_timer_vcpu_load().
Changes since v7:
 * Hide KVM_CAP_COUNTER_OFFSET for realm guests.
---
 arch/arm64/kvm/arch_timer.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 4155fe89b58a..00ff182ae288 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -56,11 +56,22 @@ static unsigned long kvm_arch_timer_get_irq_flags(void)
 	return kvm_vgic_global_state.no_hw_deactivation ? VGIC_IRQ_SW_RESAMPLE : 0;
 }
 
+static unsigned long kvm_realm_timer_get_irq_flags(void)
+{
+	/* RMI_REC_ENTER rejects LRs which have the HW bit set. */
+	return VGIC_IRQ_SW_RESAMPLE;
+}
+
 static const struct irq_ops arch_timer_irq_ops = {
 	.get_flags	 = kvm_arch_timer_get_irq_flags,
 	.get_input_level = kvm_arch_timer_get_input_level,
 };
 
+static const struct irq_ops realm_timer_irq_ops = {
+	.get_flags	 = kvm_realm_timer_get_irq_flags,
+	.get_input_level = kvm_arch_timer_get_input_level,
+};
+
 static const struct irq_ops arch_timer_irq_ops_vgic_v5 = {
 	.get_input_level = kvm_arch_timer_get_input_level,
 	.queue_irq_unlock = vgic_v5_ppi_queue_irq_unlock,
@@ -1073,7 +1084,8 @@ static void timer_context_init(struct kvm_vcpu *vcpu, int timerid)
 
 	ctxt->timer_id = timerid;
 
-	if (!kvm_vm_is_protected(vcpu->kvm)) {
+	/* The RMM architecture fixes both Realm counter offsets at zero. */
+	if (!kvm_vm_is_protected(vcpu->kvm) && !vcpu_is_rec(vcpu)) {
 		if (timerid == TIMER_VTIMER)
 			ctxt->offset.vm_offset = &kvm->arch.timer_data.voffset;
 		else
@@ -1103,8 +1115,11 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
 	for (int i = 0; i < NR_KVM_TIMERS; i++)
 		timer_context_init(vcpu, i);
 
-	/* Synchronize offsets across timers of a VM if not already provided */
-	if (!vcpu_is_protected(vcpu) &&
+	/*
+	 * Synchronize offsets across timers of a VM if not already provided.
+	 * Realm counter offsets are fixed at zero by the RMM architecture.
+	 */
+	if (!vcpu_is_protected(vcpu) && !vcpu_is_rec(vcpu) &&
 	    !test_bit(KVM_ARCH_FLAG_VM_COUNTER_OFFSET, &vcpu->kvm->arch.flags)) {
 		timer_set_offset(vcpu_vtimer(vcpu), kvm_phys_timer_read());
 		timer_set_offset(vcpu_ptimer(vcpu), 0);
@@ -1602,8 +1617,15 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu)
 
 	get_timer_map(vcpu, &map);
 
-	ops = vgic_is_v5(vcpu->kvm) ? &arch_timer_irq_ops_vgic_v5 :
-				      &arch_timer_irq_ops;
+	/*
+	 * RMI_REC_ENTER rejects LRs with the HW bit set, so use the existing
+	 * software resampling mechanism for Realm timer interrupts.
+	 */
+	if (vcpu_is_rec(vcpu))
+		ops = &realm_timer_irq_ops;
+	else
+		ops = vgic_is_v5(vcpu->kvm) ? &arch_timer_irq_ops_vgic_v5 :
+					      &arch_timer_irq_ops;
 
 	for (int i = 0; i < nr_timers(vcpu); i++)
 		kvm_vgic_set_irq_ops(vcpu, timer_irq(vcpu_get_timer(vcpu, i)), ops);
@@ -1729,7 +1751,7 @@ int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,
 	if (offset->reserved)
 		return -EINVAL;
 
-	if (kvm_vm_is_protected(kvm))
+	if (kvm_vm_is_protected(kvm) || kvm_is_realm(kvm))
 		return -EINVAL;
 
 	mutex_lock(&kvm->lock);
-- 
2.43.0

[PATCH v16 21/45] KVM: arm64: CCA: Handle realm enter/exit

[Steven Price]

Entering a realm is done using a SMC call to the RMM. On exit the
exit-codes need to be handled slightly differently to the normal KVM
path so define our own functions for realm enter/exit and hook them
in if the guest is a realm guest.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Major rewrite to use KVM requests and fit in better with the existing
   KVM code.
Changes since v13:
 * The RMM is now required to provide an ESR value with the correct
   information to emulate MMIO, so we no longer need to hardcode 0s in
   rec_exit_sys_reg().
 * The PSCI changes mean that there is a potential race when turning on
   a VCPU which can cause a RMI_ERROR_REC return. Exit to user space
   with -EAGAIN in this case.
Changes since v12:
 * Call guest_state_{enter,exit}_irqoff() around rmi_rec_enter().
 * Add handling of the IRQ exception case where IRQs need to be briefly
   enabled before exiting guest timing.
Changes since v8:
 * Introduce kvm_rec_pre_enter() called before entering an atomic
   section to handle operations that might require memory allocation
   (specifically completing a RIPAS change introduced in a later patch).
 * Updates to align with upstream changes to hpfar_el2 which now (ab)uses
   HPFAR_EL2_NS as a valid flag.
 * Fix exit reason when racing with PSCI shutdown to return
   KVM_EXIT_SHUTDOWN rather than KVM_EXIT_UNKNOWN.
Changes since v7:
 * A return of 0 from kvm_handle_sys_reg() doesn't mean the register has
   been read (although that can never happen in the current code). Tidy
   up the condition to handle any future refactoring.
Changes since v6:
 * Use vcpu_err() rather than pr_err/kvm_err when there is an associated
   vcpu to the error.
 * Return -EFAULT for KVM_EXIT_MEMORY_FAULT as per the documentation for
   this exit type.
 * Split code handling a RIPAS change triggered by the guest to the
   following patch.
Changes since v5:
 * For a RIPAS_CHANGE request from the guest perform the actual RIPAS
   change on next entry rather than immediately on the exit. This allows
   the VMM to 'reject' a RIPAS change by refusing to continue
   scheduling.
Changes since v4:
 * Rename handle_rme_exit() to handle_rec_exit()
 * Move the loop to copy registers into the REC enter structure from the
   to rec_exit_handlers callbacks to kvm_rec_enter(). This fixes a bug
   where the handler exits to user space and user space wants to modify
   the GPRS.
 * Some code rearrangement in rec_exit_ripas_change().
Changes since v2:
 * realm_set_ipa_state() now provides an output parameter for the
   top_iap that was changed. Use this to signal the VMM with the correct
   range that has been transitioned.
 * Adapt to previous patch changes.
---
 arch/arm64/include/asm/kvm_asm.h  |   2 +
 arch/arm64/include/asm/kvm_host.h |   1 +
 arch/arm64/include/asm/kvm_rmi.h  |   5 +
 arch/arm64/kvm/Makefile           |   2 +-
 arch/arm64/kvm/arm.c              |  18 +++-
 arch/arm64/kvm/handle_exit.c      |  14 +++
 arch/arm64/kvm/rmi-exit.c         | 167 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/rmi.c              |  56 ++++++++++
 8 files changed, 263 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm64/kvm/rmi-exit.c

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 043495f7fc78..0629851e1114 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -21,6 +21,7 @@
 #define ARM_EXCEPTION_EL1_SERROR  1
 #define ARM_EXCEPTION_TRAP	  2
 #define ARM_EXCEPTION_IL	  3
+#define ARM_EXCEPTION_EXIT	  4
 /* The hyp-stub will return this for any kvm_call_hyp() call */
 #define ARM_EXCEPTION_HYP_GONE	  HVC_STUB_ERR
 
@@ -28,6 +29,7 @@
 	{ARM_EXCEPTION_IRQ,		"IRQ"		},	\
 	{ARM_EXCEPTION_EL1_SERROR, 	"SERROR"	},	\
 	{ARM_EXCEPTION_TRAP, 		"TRAP"		},	\
+	{ARM_EXCEPTION_EXIT,		"EXIT"		},	\
 	{ARM_EXCEPTION_HYP_GONE,	"HYP_GONE"	}
 
 /*
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 9b46b39ed11e..15d42d1993bb 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -56,6 +56,7 @@
 #define KVM_REQ_GUEST_HYP_IRQ_PENDING	KVM_ARCH_REQ(9)
 #define KVM_REQ_MAP_L1_VNCR_EL2		KVM_ARCH_REQ(10)
 #define KVM_REQ_VGIC_PROCESS_UPDATE	KVM_ARCH_REQ(11)
+#define KVM_REQ_RMI			KVM_ARCH_REQ(12)
 
 #define KVM_DIRTY_LOG_MANUAL_CAPS   (KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE | \
 				     KVM_DIRTY_LOG_INITIALLY_SET)
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 3bffd021ca26..1e5026039458 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -102,6 +102,11 @@ void kvm_destroy_realm(struct kvm *kvm);
 int kvm_realm_teardown_stage2(struct kvm *kvm);
 void kvm_destroy_rec(struct kvm_vcpu *vcpu);
 
+int kvm_rec_enter(struct kvm_vcpu *vcpu);
+int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
+int kvm_rec_handle_request(struct kvm_vcpu *vcpu);
+bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret);
+
 static inline bool kvm_realm_is_private_address(struct realm *realm,
 						unsigned long addr)
 {
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index ed3cf30eb06e..4a2d52fdb6a2 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -16,7 +16,7 @@ CFLAGS_handle_exit.o += -Wno-override-init
 kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
 	 inject_fault.o va_layout.o handle_exit.o config.o \
 	 guest.o debug.o reset.o sys_regs.o stacktrace.o \
-	 vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o \
+	 vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o rmi-exit.o \
 	 arch_timer.o trng.o vmid.o emulate-nested.o nested.o at.o \
 	 vgic/vgic.o vgic/vgic-init.o \
 	 vgic/vgic-irqfd.o vgic/vgic-v2.o \
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 2959a1451232..3ad2f1d5b9e2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1206,6 +1206,13 @@ static int check_vcpu_requests(struct kvm_vcpu *vcpu)
 		if (kvm_check_request(KVM_REQ_SUSPEND, vcpu))
 			return kvm_vcpu_suspend(vcpu);
 
+		if (kvm_check_request(KVM_REQ_RMI, vcpu)) {
+			int ret = kvm_rec_handle_request(vcpu);
+
+			if (ret <= 0)
+				return ret;
+		}
+
 		if (kvm_dirty_ring_check_request(vcpu))
 			return 0;
 
@@ -1291,9 +1298,18 @@ static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
 	int ret;
 
 	guest_state_enter_irqoff();
-	ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu);
+	if (vcpu_is_rec(vcpu))
+		ret = kvm_rec_enter(vcpu);
+	else
+		ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu);
 	guest_state_exit_irqoff();
 
+	if (vcpu_is_rec(vcpu)) {
+		instrumentation_begin();
+		ret = kvm_rec_exit(vcpu, ret);
+		instrumentation_end();
+	}
+
 	return ret;
 }
 
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 54aedf93c78b..6950188efc68 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -18,6 +18,7 @@
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_mmu.h>
 #include <asm/kvm_nested.h>
+#include <asm/kvm_rmi.h>
 #include <asm/debug-monitors.h>
 #include <asm/stacktrace/nvhe.h>
 #include <asm/traps.h>
@@ -37,10 +38,15 @@ static void kvm_handle_guest_serror(struct kvm_vcpu *vcpu, u64 esr)
 
 static int handle_hvc(struct kvm_vcpu *vcpu)
 {
+	int ret;
+
 	trace_kvm_hvc_arm64(*vcpu_pc(vcpu), vcpu_get_reg(vcpu, 0),
 			    kvm_vcpu_hvc_get_imm(vcpu));
 	vcpu->stat.hvc_exit_stat++;
 
+	if (kvm_rec_handle_hvc(vcpu, &ret))
+		return ret;
+
 	/* Forward hvc instructions to the virtual EL2 if the guest has EL2. */
 	if (vcpu_has_nv(vcpu)) {
 		if (vcpu_read_sys_reg(vcpu, HCR_EL2) & HCR_HCD)
@@ -447,6 +453,9 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index)
 {
 	struct kvm_run *run = vcpu->run;
 
+	if (exception_index < 0)
+		return exception_index;
+
 	if (ARM_SERROR_PENDING(exception_index)) {
 		/*
 		 * The SError is handled by handle_exit_early(). If the guest
@@ -478,6 +487,8 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index)
 		 */
 		run->exit_reason = KVM_EXIT_FAIL_ENTRY;
 		return -EINVAL;
+	case ARM_EXCEPTION_EXIT:
+		return 0;
 	default:
 		kvm_pr_unimpl("Unsupported exception type: %d",
 			      exception_index);
@@ -489,6 +500,9 @@ int handle_exit(struct kvm_vcpu *vcpu, int exception_index)
 /* For exit types that need handling before we can be preempted */
 void handle_exit_early(struct kvm_vcpu *vcpu, int exception_index)
 {
+	if (exception_index < 0 || exception_index == ARM_EXCEPTION_EXIT)
+		return;
+
 	if (ARM_SERROR_PENDING(exception_index)) {
 		if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN)) {
 			u64 disr = kvm_vcpu_get_disr(vcpu);
diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c
new file mode 100644
index 000000000000..04e6535552cb
--- /dev/null
+++ b/arch/arm64/kvm/rmi-exit.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <linux/arm-smccc-rmi.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_rmi.h>
+#include <asm/kvm_mmu.h>
+
+static int rec_exit_fatal(struct kvm_vcpu *vcpu, const char *reason,
+			  unsigned long value)
+{
+	vcpu_err(vcpu, "%s: %#lx\n", reason, value);
+	vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+	kvm_vm_dead(vcpu->kvm);
+	return ARM_EXCEPTION_EXIT;
+}
+
+static void rec_exit_sync(struct kvm_vcpu *vcpu)
+{
+	struct realm_rec *rec = &vcpu->arch.rec;
+	u64 esr = rec->run->exit.esr;
+	u8 ec = ESR_ELx_EC(esr);
+
+	switch (ec) {
+	case ESR_ELx_EC_SYS64: {
+		int rt = ESR_ELx_SYS64_ISS_RT(esr);
+		bool is_write = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) ==
+				ESR_ELx_SYS64_ISS_DIR_WRITE;
+
+		if (is_write && rt < REC_RUN_GPRS)
+			vcpu_set_reg(vcpu, rt, rec->run->exit.gprs[rt]);
+		else if (!is_write)
+			kvm_make_request(KVM_REQ_RMI, vcpu);
+		break;
+	}
+	}
+}
+
+static void rec_exit_hvc(struct kvm_vcpu *vcpu)
+{
+	struct realm_rec *rec = &vcpu->arch.rec;
+	int i;
+
+	for (i = 0; i < REC_RUN_GPRS; i++)
+		vcpu_set_reg(vcpu, i, rec->run->exit.gprs[i]);
+
+	vcpu->arch.fault.esr_el2 = (ESR_ELx_EC_HVC64 << ESR_ELx_EC_SHIFT) |
+				     ESR_ELx_IL;
+}
+
+bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret)
+{
+	struct realm_rec *rec;
+	struct realm *realm;
+	unsigned long base;
+	unsigned long ripas;
+	unsigned long top;
+
+	if (!vcpu_is_rec(vcpu))
+		return false;
+
+	rec = &vcpu->arch.rec;
+	if (rec->run->exit.exit_reason != RMI_EXIT_RIPAS_CHANGE)
+		return false;
+
+	realm = &vcpu->kvm->arch.realm;
+	base = rec->run->exit.ripas_base;
+	top = rec->run->exit.ripas_top;
+	ripas = rec->run->exit.ripas_value;
+
+	if (top <= base ||
+	    !kvm_realm_is_private_address(realm, base) ||
+	    !kvm_realm_is_private_address(realm, top - 1)) {
+		vcpu_err(vcpu, "Invalid RIPAS_CHANGE for %#lx - %#lx, ripas: %#lx\n",
+			 base, top, ripas);
+		/* Set RMI_REJECT bit */
+		rec->run->enter.flags = REC_ENTER_FLAG_RIPAS_RESPONSE;
+		*ret = -EINVAL;
+		return true;
+	}
+
+	/* Exit to VMM, the actual RIPAS change is done on next entry */
+	kvm_prepare_memory_fault_exit(vcpu, base, top - base, false, false,
+				      ripas == RMI_RAM);
+	kvm_make_request(KVM_REQ_RMI, vcpu);
+
+	/*
+	 * KVM_EXIT_MEMORY_FAULT requires a return code of -EFAULT, see the
+	 * API documentation
+	 */
+	*ret = -EFAULT;
+	return true;
+}
+
+int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
+{
+	struct realm_rec *rec = &vcpu->arch.rec;
+	unsigned long status;
+
+	if (rec_run_ret < 0)
+		return rec_exit_fatal(vcpu, "REC_ENTER failed", rec_run_ret);
+
+	status = RMI_RETURN_STATUS(rec_run_ret);
+
+	/*
+	 * If a PSCI_SYSTEM_OFF request raced with a vcpu executing, we might
+	 * see the following status code indicating an attempt to run
+	 * a REC when the RD state is SYSTEM_OFF.  In this case, we just need to
+	 * return to user space which can deal with the system event or will try
+	 * to run the KVM VCPU again, at which point we will no longer attempt
+	 * to enter the Realm because we will have a sleep request pending on
+	 * the VCPU as a result of KVM's PSCI handling.
+	 */
+	if (status == RMI_ERROR_REALM) {
+		vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
+		return ARM_EXCEPTION_EXIT;
+	}
+
+	/*
+	 * If a VCPU has been turned on, but the REC state hasn't been updated
+	 * we may experience RMI_ERROR_REC. Exit to the userspace with -EAGAIN
+	 * for a retry.
+	 */
+	if (status == RMI_ERROR_REC)
+		return -EAGAIN;
+	if (rec_run_ret)
+		return rec_exit_fatal(vcpu, "Unexpected REC_ENTER status",
+				      rec_run_ret);
+
+	vcpu->arch.fault.esr_el2 = rec->run->exit.esr;
+	vcpu->arch.fault.far_el2 = rec->run->exit.far;
+	/* HPFAR_EL2 is only valid for RMI_EXIT_SYNC */
+	vcpu->arch.fault.hpfar_el2 = 0;
+
+	/* Reset the emulation flags for the next run of the REC */
+	rec->run->enter.flags = 0;
+
+	switch (rec->run->exit.exit_reason) {
+	case RMI_EXIT_SYNC:
+		/*
+		 * HPFAR_EL2_NS is hijacked to indicate a valid HPFAR value,
+		 * see __get_fault_info()
+		 */
+		vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar | HPFAR_EL2_NS;
+		rec_exit_sync(vcpu);
+		return ARM_EXCEPTION_TRAP;
+	case RMI_EXIT_IRQ:
+	case RMI_EXIT_FIQ:
+		return ARM_EXCEPTION_IRQ;
+	case RMI_EXIT_SERROR:
+		return ARM_EXCEPTION_EL1_SERROR;
+	case RMI_EXIT_PSCI:
+		rec_exit_hvc(vcpu);
+		kvm_make_request(KVM_REQ_RMI, vcpu);
+		return ARM_EXCEPTION_TRAP;
+	case RMI_EXIT_RIPAS_CHANGE:
+		rec_exit_hvc(vcpu);
+		return ARM_EXCEPTION_TRAP;
+	}
+
+	return rec_exit_fatal(vcpu, "Unsupported Realm exit reason",
+			      rec->run->exit.exit_reason);
+}
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index f6686287119d..92085b88f427 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -6,6 +6,7 @@
 #include <linux/kvm_host.h>
 
 #include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 #include <asm/kvm_pgtable.h>
 #include <asm/rmi_cmds.h>
@@ -205,6 +206,61 @@ int kvm_realm_teardown_stage2(struct kvm *kvm)
 	return realm_destroy_rtts(kvm);
 }
 
+int kvm_rec_handle_request(struct kvm_vcpu *vcpu)
+{
+	struct realm_rec *rec = &vcpu->arch.rec;
+	u64 esr;
+
+	switch (rec->run->exit.exit_reason) {
+	case RMI_EXIT_SYNC:
+		esr = rec->run->exit.esr;
+		if (ESR_ELx_EC(esr) == ESR_ELx_EC_SYS64 &&
+		    (esr & ESR_ELx_SYS64_ISS_DIR_MASK) ==
+				ESR_ELx_SYS64_ISS_DIR_READ) {
+			int rt = ESR_ELx_SYS64_ISS_RT(esr);
+
+			if (rt < REC_RUN_GPRS)
+				rec->run->enter.gprs[rt] =
+					vcpu_get_reg(vcpu, rt);
+		}
+		break;
+	default:
+		KVM_BUG(1, vcpu->kvm, "Unhandled realm exit_reason");
+		return -ENXIO;
+	}
+
+	return 1;
+}
+
+static void noinstr load_realm_timer_state(struct kvm_vcpu *vcpu)
+{
+	struct rec_exit *rec_exit = &vcpu->arch.rec.run->exit;
+
+	/*
+	 * The RMM reports the EL1 timer state on every REC exit. Install that
+	 * state before returning to the generic KVM run loop, which expects
+	 * the loaded vCPU's timers to be live.
+	 */
+	write_sysreg_el0(rec_exit->cntv_cval, SYS_CNTV_CVAL);
+	write_sysreg_el0(rec_exit->cntp_cval, SYS_CNTP_CVAL);
+	isb();
+
+	write_sysreg_el0(rec_exit->cntv_ctl, SYS_CNTV_CTL);
+	write_sysreg_el0(rec_exit->cntp_ctl, SYS_CNTP_CTL);
+}
+
+int noinstr kvm_rec_enter(struct kvm_vcpu *vcpu)
+{
+	struct realm_rec *rec = &vcpu->arch.rec;
+	int ret;
+
+	ret = rmi_rec_enter(rec->rec_phys, rec->run_phys);
+	if (!ret)
+		load_realm_timer_state(vcpu);
+
+	return ret;
+}
+
 static int __maybe_unused kvm_create_rec(struct kvm_vcpu *vcpu)
 {
 	struct user_pt_regs *vcpu_regs = vcpu_gp_regs(vcpu);
-- 
2.43.0

[PATCH v16 22/45] KVM: arm64: CCA: Handle RMI_EXIT_RIPAS_CHANGE

[Steven Price]

The guest can request that a region of its protected address space is
switched between RIPAS_RAM and RIPAS_EMPTY (and back) using
RSI_IPA_STATE_SET. This causes a guest exit with the
RMI_EXIT_RIPAS_CHANGE code. We treat this as a request to convert a
protected region to unprotected (or back), exiting to the VMM to make
the necessary changes to the guest_memfd and memslot mappings. On the
next entry the RIPAS changes are committed by making RMI_RTT_SET_RIPAS
calls.

The VMM may wish to reject the RIPAS change requested by the guest. For
now it can only do this by no longer scheduling the VCPU as we don't
currently have a usecase for returning that rejection to the guest, but
by postponing the RMI_RTT_SET_RIPAS changes to entry we leave the door
open for adding a new ioctl in the future for this purpose.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Propagate negative error returns.
Changes since v14:
 * Use addition rather than bitwise OR for adding the shared_bit in
   realm_unmap_shared_range(), this handles the case where the region
   includes the last address (which means 'end' already has the bit
   set).
Changes since v13:
 * Switch to the new RMI_RTT_UNPROT_UNMAP range-based API.
 * Drop ugly hack for RMM bug which errored when the RIPAS was already
   set to the desired value.
Changes since v12:
 * Switch to the new RMM v2.0 RMI_RTT_DATA_UNMAP which can unmap an
   address range.
Changes since v11:
 * Combine the "Allow VMM to set RIPAS" patch into this one to avoid
   adding functions before they are used.
 * Drop the CAP for setting RIPAS and adapt to changes from previous
   patches.
Changes since v10:
 * Add comment explaining the assignment of rec->run->exit.ripas_base in
   kvm_complete_ripas_change().
Changes since v8:
 * Make use of ripas_change() from a previous patch to implement
   realm_set_ipa_state().
 * Update exit.ripas_base after a RIPAS change so that, if instead of
   entering the guest we exit to user space, we don't attempt to repeat
   the RIPAS change (triggering an error from the RMM).
Changes since v7:
 * Rework the loop in realm_set_ipa_state() to make it clear when the
   'next' output value of rmi_rtt_set_ripas() is used.
New patch for v7: The code was previously split awkwardly between two
other patches.
---
 arch/arm64/include/asm/kvm_rmi.h |   6 +
 arch/arm64/kvm/mmu.c             |   8 +-
 arch/arm64/kvm/rmi.c             | 473 +++++++++++++++++++++++++++++++
 3 files changed, 484 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 1e5026039458..751659a48be3 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -107,6 +107,12 @@ int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
 int kvm_rec_handle_request(struct kvm_vcpu *vcpu);
 bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret);
 
+void kvm_realm_unmap_range(struct kvm *kvm,
+			   unsigned long ipa,
+			   unsigned long size,
+			   bool unmap_private,
+			   bool may_block);
+
 static inline bool kvm_realm_is_private_address(struct realm *realm,
 						unsigned long addr)
 {
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index cd06881c1497..dcc2ab08d0e4 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -319,6 +319,7 @@ static void invalidate_icache_guest_page(void *va, size_t size)
  * @start: The intermediate physical base address of the range to unmap
  * @size:  The size of the area to unmap
  * @may_block: Whether or not we are permitted to block
+ * @only_shared: If true then protected mappings should not be unmapped
  *
  * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
  * be called while holding mmu_lock (unless for freeing the stage2 pgd before
@@ -326,7 +327,7 @@ static void invalidate_icache_guest_page(void *va, size_t size)
  * with things behind our backs.
  */
 static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64 size,
-				 bool may_block)
+				 bool may_block, bool only_shared)
 {
 	struct kvm *kvm = kvm_s2_mmu_to_kvm(mmu);
 	phys_addr_t end = start + size;
@@ -343,7 +344,7 @@ void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start,
 	if (kvm_vm_is_protected(kvm_s2_mmu_to_kvm(mmu)))
 		return;
 
-	__unmap_stage2_range(mmu, start, size, may_block);
+	__unmap_stage2_range(mmu, start, size, may_block, false);
 }
 
 void kvm_stage2_flush_range(struct kvm_s2_mmu *mmu, phys_addr_t addr, phys_addr_t end)
@@ -2467,7 +2468,8 @@ bool kvm_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range)
 
 	__unmap_stage2_range(&kvm->arch.mmu, range->start << PAGE_SHIFT,
 			     (range->end - range->start) << PAGE_SHIFT,
-			     range->may_block);
+			     range->may_block,
+			     !(range->attr_filter & KVM_FILTER_PRIVATE));
 
 	kvm_nested_s2_unmap(kvm, range->may_block);
 	return false;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 92085b88f427..a7202054c8e6 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -35,6 +35,83 @@ static int get_start_level(struct realm *realm)
 	return 4 - stage2_pgtable_levels(realm->ia_bits);
 }
 
+static int find_map_level(struct realm *realm,
+			  unsigned long start,
+			  unsigned long end)
+{
+	int level = KVM_PGTABLE_LAST_LEVEL;
+
+	while (level > get_start_level(realm)) {
+		unsigned long map_size = rmi_rtt_level_mapsize(level - 1);
+
+		if (!IS_ALIGNED(start, map_size) ||
+		    (start + map_size) > end)
+			break;
+
+		level--;
+	}
+
+	return level;
+}
+
+static unsigned long rmi_range_entry_size(int rmi_size)
+{
+	if (WARN_ON(rmi_size > KVM_PGTABLE_LAST_LEVEL))
+		return 0;
+
+	return kvm_granule_size(KVM_PGTABLE_LAST_LEVEL - rmi_size);
+}
+
+static int undelegate_range_desc(unsigned long desc)
+{
+	unsigned long size = rmi_range_entry_size(RMI_ADDR_RANGE_SIZE(desc));
+	unsigned long count = RMI_ADDR_RANGE_COUNT(desc);
+	unsigned long addr = RMI_ADDR_RANGE_ADDR(desc);
+	unsigned long state = RMI_ADDR_RANGE_STATE(desc);
+
+	if (state == RMI_OP_MEM_UNDELEGATED)
+		return 0;
+
+	if (size * count == 0)
+		return 0;
+
+	return rmi_undelegate_range(addr, size * count);
+}
+
+static phys_addr_t alloc_delegated_granule(struct kvm_mmu_memory_cache *mc)
+{
+	phys_addr_t phys;
+	void *virt;
+
+	if (mc) {
+		virt = kvm_mmu_memory_cache_alloc(mc);
+	} else {
+		virt = (void *)__get_free_page(GFP_ATOMIC | __GFP_ZERO |
+					       __GFP_ACCOUNT);
+	}
+
+	if (!virt)
+		return PHYS_ADDR_MAX;
+
+	phys = virt_to_phys(virt);
+	if (rmi_delegate_page(phys)) {
+		free_page((unsigned long)virt);
+		return PHYS_ADDR_MAX;
+	}
+
+	return phys;
+}
+
+static phys_addr_t alloc_rtt(struct kvm_mmu_memory_cache *mc)
+{
+	phys_addr_t phys = alloc_delegated_granule(mc);
+
+	if (phys != PHYS_ADDR_MAX)
+		kvm_account_pgtable_pages(phys_to_virt(phys), 1);
+
+	return phys;
+}
+
 static void free_rtt(phys_addr_t phys)
 {
 	if (free_delegated_page(phys))
@@ -43,6 +120,32 @@ static void free_rtt(phys_addr_t phys)
 	kvm_account_pgtable_pages(phys_to_virt(phys), -1);
 }
 
+static long realm_rtt_create(struct realm *realm,
+			     unsigned long addr,
+			     int level,
+			     phys_addr_t phys)
+{
+	addr = ALIGN_DOWN(addr, rmi_rtt_level_mapsize(level - 1));
+	return rmi_rtt_create(virt_to_phys(realm->rd), phys, addr, level);
+}
+
+static long realm_rtt_fold(struct realm *realm,
+			   unsigned long addr,
+			   int level,
+			   phys_addr_t *rtt_granule)
+{
+	unsigned long out_rtt;
+	long ret;
+
+	addr = ALIGN_DOWN(addr, rmi_rtt_level_mapsize(level - 1));
+	ret = rmi_rtt_fold(virt_to_phys(realm->rd), addr, level, &out_rtt);
+
+	if (rtt_granule)
+		*rtt_granule = out_rtt;
+
+	return ret;
+}
+
 /*
  * realm_rtt_destroy - Destroy an RTT at @level for @addr.
  *
@@ -66,6 +169,43 @@ static long realm_rtt_destroy(struct realm *realm, unsigned long addr,
 	return ret;
 }
 
+static int realm_create_rtt_levels(struct realm *realm,
+				   unsigned long ipa,
+				   int level,
+				   int max_level,
+				   struct kvm_mmu_memory_cache *mc)
+{
+	while (level++ < max_level) {
+		phys_addr_t rtt = alloc_rtt(mc);
+		long ret;
+
+		if (rtt == PHYS_ADDR_MAX)
+			return -ENOMEM;
+
+		ret = realm_rtt_create(realm, ipa, level, rtt);
+		if (ret < 0) {
+			free_rtt(rtt);
+			return ret;
+		}
+
+		if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT &&
+		    RMI_RETURN_INDEX(ret) == level - 1) {
+			/* The RTT already exists, continue */
+			free_rtt(rtt);
+			continue;
+		}
+
+		if (ret) {
+			WARN(1, "Failed to create RTT at level %d: %ld\n",
+			     level, ret);
+			free_rtt(rtt);
+			return -ENXIO;
+		}
+	}
+
+	return 0;
+}
+
 static int realm_tear_down_rtt_level(struct realm *realm, int level,
 				     unsigned long start, unsigned long end)
 {
@@ -162,6 +302,64 @@ static int realm_tear_down_rtt_range(struct realm *realm,
 					 start, end);
 }
 
+/*
+ * Returns 0 on successful fold, a negative value on error, a positive value if
+ * we were not able to fold all tables at this level.
+ */
+static int realm_fold_rtt_level(struct realm *realm, int level,
+				unsigned long start, unsigned long end)
+{
+	int not_folded = 0;
+	ssize_t map_size;
+	unsigned long addr, next_addr;
+
+	if (WARN_ON(level > KVM_PGTABLE_LAST_LEVEL))
+		return -EINVAL;
+
+	map_size = rmi_rtt_level_mapsize(level - 1);
+
+	for (addr = start; addr < end; addr = next_addr) {
+		phys_addr_t rtt_granule;
+		long ret;
+		unsigned long align_addr = ALIGN(addr, map_size);
+
+		next_addr = ALIGN(addr + 1, map_size);
+
+		ret = realm_rtt_fold(realm, align_addr, level, &rtt_granule);
+		if (ret < 0)
+			return ret;
+
+		switch (RMI_RETURN_STATUS(ret)) {
+		case RMI_SUCCESS:
+			free_rtt(rtt_granule);
+			break;
+		case RMI_ERROR_RTT:
+			if (level == KVM_PGTABLE_LAST_LEVEL ||
+			    RMI_RETURN_INDEX(ret) < level) {
+				not_folded++;
+				break;
+			}
+			/* Recurse a level deeper */
+			ret = realm_fold_rtt_level(realm,
+						   level + 1,
+						   addr,
+						   next_addr);
+			if (ret < 0) {
+				return ret;
+			} else if (ret == 0) {
+				/* Try again at this level */
+				next_addr = addr;
+			}
+			break;
+		default:
+			WARN_ON(1);
+			return -ENXIO;
+		}
+	}
+
+	return not_folded;
+}
+
 static int realm_destroy_rtts(struct kvm *kvm)
 {
 	struct realm *realm = &kvm->arch.realm;
@@ -206,6 +404,279 @@ int kvm_realm_teardown_stage2(struct kvm *kvm)
 	return realm_destroy_rtts(kvm);
 }
 
+static void realm_unmap_shared_range(struct kvm *kvm,
+				     unsigned long start,
+				     unsigned long end,
+				     bool may_block)
+{
+	struct realm *realm = &kvm->arch.realm;
+	unsigned long rd = virt_to_phys(realm->rd);
+	unsigned long next_addr, addr;
+	unsigned long shared_bit = BIT(realm->ia_bits - 1);
+
+	if (start >= end)
+		return;
+
+	start += shared_bit;
+	end += shared_bit;
+
+	for (addr = start; addr < end; addr = next_addr) {
+		long ret;
+
+		ret = rmi_rtt_unprot_unmap(rd, addr, end, RMI_ADDR_TYPE_NONE,
+					   0, &next_addr, NULL, NULL);
+		if (WARN_ON(ret < 0))
+			return;
+
+		switch (RMI_RETURN_STATUS(ret)) {
+		case RMI_SUCCESS:
+			break;
+		case RMI_ERROR_RTT: {
+			int err_level = RMI_RETURN_INDEX(ret);
+			int level = find_map_level(realm, addr, end);
+
+			if (err_level >= level) {
+				/* Nothing present, so skip */
+				next_addr = addr + rmi_rtt_level_mapsize(err_level);
+				break;
+			}
+
+			ret = realm_create_rtt_levels(realm, addr, err_level,
+						      level, NULL);
+			if (WARN_ON(ret))
+				return;
+			/* Retry with the RTT levels in place */
+			next_addr = addr;
+			break;
+		}
+		default:
+			WARN_ON(1);
+			return;
+		}
+
+		if (may_block)
+			cond_resched_rwlock_write(&kvm->mmu_lock);
+	}
+
+	realm_fold_rtt_level(realm, get_start_level(realm) + 1,
+			     start, end);
+}
+
+static void realm_unmap_private_range(struct kvm *kvm,
+				      unsigned long start,
+				      unsigned long end,
+				      bool may_block)
+{
+	struct realm *realm = &kvm->arch.realm;
+	unsigned long rd = virt_to_phys(realm->rd);
+	unsigned long next_addr, addr;
+	long ret;
+
+	for (addr = start; addr < end; addr = next_addr) {
+		unsigned long out_range;
+		unsigned long flags = RMI_ADDR_TYPE_SINGLE;
+		/* TODO: Optimise using RMI_ADDR_TYPE_LIST */
+
+retry:
+		ret = rmi_rtt_data_unmap(rd, addr, end, flags, 0,
+					 &next_addr, &out_range, NULL);
+		if (WARN_ON(ret < 0))
+			return;
+
+		if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+			phys_addr_t rtt;
+
+			if (next_addr > addr)
+				continue; /* UNASSIGNED */
+
+			rtt = alloc_rtt(NULL);
+			if (WARN_ON(rtt == PHYS_ADDR_MAX))
+				return;
+			ret = realm_rtt_create(realm, addr,
+					       RMI_RETURN_INDEX(ret) + 1, rtt);
+			if (WARN_ON(ret)) {
+				free_rtt(rtt);
+				return;
+			}
+			goto retry;
+		} else if (WARN_ON(ret)) {
+			continue;
+		}
+
+		ret = undelegate_range_desc(out_range);
+		if (WARN_ON(ret))
+			break;
+
+		if (may_block)
+			cond_resched_rwlock_write(&kvm->mmu_lock);
+	}
+
+	realm_fold_rtt_level(realm, get_start_level(realm) + 1,
+			     start, end);
+}
+
+void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start,
+			   unsigned long size, bool unmap_private,
+			   bool may_block)
+{
+	unsigned long end = start + size;
+	struct realm *realm = &kvm->arch.realm;
+
+	if (!kvm_realm_is_created(kvm))
+		return;
+
+	end = min(BIT(realm->ia_bits - 1), end);
+
+	realm_unmap_shared_range(kvm, start, end, may_block);
+	if (unmap_private)
+		realm_unmap_private_range(kvm, start, end, may_block);
+}
+
+enum ripas_action {
+	RIPAS_INIT,
+	RIPAS_SET,
+};
+
+static int ripas_change(struct kvm *kvm,
+			struct kvm_vcpu *vcpu,
+			unsigned long ipa,
+			unsigned long end,
+			enum ripas_action action,
+			unsigned long *top_ipa)
+{
+	struct realm *realm = &kvm->arch.realm;
+	phys_addr_t rd_phys = virt_to_phys(realm->rd);
+	phys_addr_t rec_phys;
+	struct kvm_mmu_memory_cache *memcache = NULL;
+	long ret = 0;
+
+	if (vcpu) {
+		rec_phys = vcpu->arch.rec.rec_phys;
+		memcache = &vcpu->arch.mmu_page_cache;
+
+		WARN_ON(action != RIPAS_SET);
+	} else {
+		WARN_ON(action != RIPAS_INIT);
+	}
+
+	while (ipa < end) {
+		unsigned long next = ~0;
+
+		switch (action) {
+		case RIPAS_INIT:
+			ret = rmi_rtt_init_ripas(rd_phys, ipa, end, &next);
+			break;
+		case RIPAS_SET:
+			ret = rmi_rtt_set_ripas(rd_phys, rec_phys, ipa, end,
+						&next);
+			break;
+		}
+
+		if (ret < 0)
+			goto out;
+
+		switch (RMI_RETURN_STATUS(ret)) {
+		case RMI_SUCCESS:
+			ipa = next;
+			break;
+		case RMI_ERROR_RTT: {
+			int err_level = RMI_RETURN_INDEX(ret);
+			int level = find_map_level(realm, ipa, end);
+
+			/*
+			 * If the operation failed at deeper level than
+			 * what is required for the address range, this
+			 * implies encountering an unexpected entry,
+			 * (e.g., RIPAS_DESTROYED), which the RMM prevents
+			 * us from modifying. This is only applicable for
+			 * RMI_RTT_INIT_RIPAS. All the other requests
+			 * are generated by the Realm and thus RMM should
+			 * be able to allow the transition.
+			 */
+			if (action == RIPAS_INIT && WARN_ON_ONCE(err_level >= level))
+				return -ENXIO;
+
+			ret = realm_create_rtt_levels(realm, ipa, err_level,
+						      level, memcache);
+			if (ret)
+				goto out;
+			/* Retry with the RTT levels in place */
+			break;
+		}
+		default:
+			WARN_ON(1);
+			ret = -ENXIO;
+			goto out;
+		}
+	}
+
+out:
+	if (top_ipa)
+		*top_ipa = ipa;
+
+	return ret;
+}
+
+static int realm_set_ipa_state(struct kvm_vcpu *vcpu,
+			       unsigned long start,
+			       unsigned long end,
+			       unsigned long ripas,
+			       unsigned long *top_ipa)
+{
+	struct kvm *kvm = vcpu->kvm;
+	int ret = ripas_change(kvm, vcpu, start, end, RIPAS_SET, top_ipa);
+
+	if (!ret && ripas == RMI_EMPTY && *top_ipa != start)
+		realm_unmap_private_range(kvm, start, *top_ipa, false);
+
+	return ret;
+}
+
+static int kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	struct realm_rec *rec = &vcpu->arch.rec;
+	unsigned long base = rec->run->exit.ripas_base;
+	unsigned long top = rec->run->exit.ripas_top;
+	unsigned long ripas = rec->run->exit.ripas_value;
+	unsigned long top_ipa = base;
+	int ret;
+
+	do {
+		kvm_mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache,
+					   kvm_mmu_cache_min_pages(vcpu->arch.hw_mmu));
+		write_lock(&kvm->mmu_lock);
+		ret = realm_set_ipa_state(vcpu, base, top, ripas, &top_ipa);
+		write_unlock(&kvm->mmu_lock);
+
+		if (ret == -ENOMEM) {
+			/* If no progress, then stop */
+			if (top_ipa == base)
+				break;
+			base = top_ipa;
+			continue;
+		}
+
+		if (WARN_RATELIMIT(ret,
+				   "Unable to satisfy RIPAS_CHANGE for %#lx - %#lx, ripas: %#lx\n",
+				   base, top, ripas))
+			break;
+
+		base = top_ipa;
+	} while (base < top);
+
+	/*
+	 * If this function is called again before the REC_ENTER call then
+	 * avoid calling realm_set_ipa_state() again by changing to the value
+	 * of ripas_base for the part that has already been covered. The RMM
+	 * ignores the contains of the rec_exit structure so this doesn't
+	 * affect the RMM.
+	 */
+	rec->run->exit.ripas_base = base;
+
+	return 1;
+}
+
 int kvm_rec_handle_request(struct kvm_vcpu *vcpu)
 {
 	struct realm_rec *rec = &vcpu->arch.rec;
@@ -224,6 +695,8 @@ int kvm_rec_handle_request(struct kvm_vcpu *vcpu)
 					vcpu_get_reg(vcpu, rt);
 		}
 		break;
+	case RMI_EXIT_RIPAS_CHANGE:
+		return kvm_complete_ripas_change(vcpu);
 	default:
 		KVM_BUG(1, vcpu->kvm, "Unhandled realm exit_reason");
 		return -ENXIO;
-- 
2.43.0

[PATCH v16 23/45] KVM: arm64: CCA: Handle realm MMIO emulation

[Steven Price]

MMIO emulation for a realm cannot be done directly with the VM's
registers as they are protected from the host. However, for emulatable
data aborts, the RMM uses GPRS[0] to provide the read/written value.
We can transfer this from/to the equivalent VCPU's register entry and
then depend on the generic MMIO handling code in KVM.

For a MMIO read, the value is placed in the shared RecExit structure
during kvm_handle_mmio_return() rather than in the VCPU's register
entry.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Adapt to the new exit flow.
Changes since v7:
 * New comment for rec_exit_sync_dabt() explaining the call to
   vcpu_set_reg().
Changes since v5:
 * Inject SEA to the guest is an emulatable MMIO access triggers a data
   abort.
 * kvm_handle_mmio_return() - disable kvm_incr_pc() for a REC (as the PC
   isn't under the host's control) and move the REC_ENTER_EMULATED_MMIO
   flag setting to this location (as that tells the RMM to skip the
   instruction).
---
 arch/arm64/kvm/inject_fault.c |  4 +++-
 arch/arm64/kvm/mmio.c         | 16 ++++++++++++----
 arch/arm64/kvm/rmi-exit.c     | 10 ++++++++++
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index 89982bd3345f..6492397b73d7 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -228,7 +228,9 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
 
 static void __kvm_inject_sea(struct kvm_vcpu *vcpu, bool iabt, u64 addr)
 {
-	if (vcpu_el1_is_32bit(vcpu))
+	if (unlikely(vcpu_is_rec(vcpu)))
+		vcpu->arch.rec.run->enter.flags |= REC_ENTER_FLAG_INJECT_SEA;
+	else if (vcpu_el1_is_32bit(vcpu))
 		inject_abt32(vcpu, iabt, addr);
 	else
 		inject_abt64(vcpu, iabt, addr);
diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
index e2285ed8c91d..a8c125205695 100644
--- a/arch/arm64/kvm/mmio.c
+++ b/arch/arm64/kvm/mmio.c
@@ -6,6 +6,7 @@
 
 #include <linux/kvm_host.h>
 #include <asm/kvm_emulate.h>
+#include <linux/arm-smccc-rmi.h>
 #include <trace/events/kvm.h>
 
 #include "trace.h"
@@ -138,14 +139,21 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
 		trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
 			       &data);
 		data = vcpu_data_host_to_guest(vcpu, data, len);
-		vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data);
+
+		if (vcpu_is_rec(vcpu))
+			vcpu->arch.rec.run->enter.gprs[0] = data;
+		else
+			vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu), data);
 	}
 
 	/*
 	 * The MMIO instruction is emulated and should not be re-executed
 	 * in the guest.
 	 */
-	kvm_incr_pc(vcpu);
+	if (vcpu_is_rec(vcpu))
+		vcpu->arch.rec.run->enter.flags |= REC_ENTER_FLAG_EMULATED_MMIO;
+	else
+		kvm_incr_pc(vcpu);
 
 	return 1;
 }
@@ -167,14 +175,14 @@ int io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
 	 * No valid syndrome? Ask userspace for help if it has
 	 * volunteered to do so, and bail out otherwise.
 	 *
-	 * In the protected VM case, there isn't much userspace can do
+	 * In the protected/realm VM case, there isn't much userspace can do
 	 * though, so directly deliver an exception to the guest.
 	 */
 	if (!kvm_vcpu_dabt_isvalid(vcpu)) {
 		trace_kvm_mmio_nisv(*vcpu_pc(vcpu), esr,
 				    kvm_vcpu_get_hfar(vcpu), fault_ipa);
 
-		if (vcpu_is_protected(vcpu))
+		if (vcpu_is_protected(vcpu) || vcpu_is_rec(vcpu))
 			return kvm_inject_sea_dabt(vcpu, kvm_vcpu_get_hfar(vcpu));
 
 		if (test_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER,
diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c
index 04e6535552cb..1749cde2edff 100644
--- a/arch/arm64/kvm/rmi-exit.c
+++ b/arch/arm64/kvm/rmi-exit.c
@@ -37,6 +37,16 @@ static void rec_exit_sync(struct kvm_vcpu *vcpu)
 			kvm_make_request(KVM_REQ_RMI, vcpu);
 		break;
 	}
+	case ESR_ELx_EC_DABT_LOW:
+		/*
+		 * The RMM reports the value of an MMIO write in gprs[0],
+		 * irrespective of the register named by the instruction.
+		 */
+		if (kvm_vcpu_dabt_iswrite(vcpu) &&
+		    kvm_vcpu_dabt_isvalid(vcpu))
+			vcpu_set_reg(vcpu, kvm_vcpu_dabt_get_rd(vcpu),
+				     rec->run->exit.gprs[0]);
+		break;
 	}
 }
 
-- 
2.43.0

[PATCH v16 24/45] KVM: arm64: Expose support for private memory

[Steven Price]

Select KVM_GENERIC_MEMORY_ATTRIBUTES and provide the necessary support
functions.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v14:
 * Switch to guest_memfd in-place memory conversion and drop support
   for KVM_VM_MEMORY_ATTRIBUTES.
Changes since v13:
 * Also update documentation to show that KVM_CAP_MEMORY_ATTRIBUTES is
   used on arm64.
Changes since v12:
 * Only define kvm_arch_has_private_mem() when
   CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES is set to avoid build issues
   when KVM is disabled.
Changes since v10:
 * KVM_GENERIC_PRIVATE_MEM replacd with KVM_GENERIC_MEMORY_ATTRIBUTES.
Changes since v9:
 * Drop the #ifdef CONFIG_KVM_PRIVATE_MEM guard from the definition of
   kvm_arch_has_private_mem()
Changes since v2:
 * Switch kvm_arch_has_private_mem() to a macro to avoid overhead of a
   function call.
 * Guard definitions of kvm_arch_{pre,post}_set_memory_attributes() with
   #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES.
 * Early out in kvm_arch_post_set_memory_attributes() if the WARN_ON
   should trigger.
---
 arch/arm64/include/asm/kvm_host.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 15d42d1993bb..146c52f867c0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1510,6 +1510,8 @@ struct kvm *kvm_arch_alloc_vm(void);
 
 #define vcpu_is_protected(vcpu)		kvm_vm_is_protected((vcpu)->kvm)
 
+#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.is_realm)
+
 int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
 bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
 
-- 
2.43.0

[PATCH v16 25/45] KVM: arm64: CCA: Create the realm descriptor

[Steven Price]

Creating a realm involves first creating a realm descriptor (RD). This
involves passing the configuration information to the RMM. Do this as
part of realm_ensure_created() so that the realm is created when it is
first needed. The call to realm_ensure_created() will be added in a
later patch.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * The page for realm parameters is now only temporarily allocated in
   realm_create_rd().
 * Deal with negative error codes.
Changes since v14:
 * Explicitly set hash_algo = RMI_HASH_SHA_256 (which is the default).
 * Support SRO flow during realm creation.
Changes since v13:
 * The RMM no longer uses AUX granules, so no need to ask it how many it
   needs.
 * Adapted to other changes.
Changes since v12:
 * Since RMM page size is now equal to the host's page size various
   calculations are simplified.
 * Switch to using range based APIs to delegate/undelegate.
 * VMID handling is now handled entirely by the RMM.
---
 arch/arm64/kvm/rmi.c | 95 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index a7202054c8e6..31eedf78a752 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -462,6 +462,83 @@ static void realm_unmap_shared_range(struct kvm *kvm,
 			     start, end);
 }
 
+static int realm_create_rd(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+	struct realm_params *params __free(free_page) = NULL;
+	void *rd = NULL;
+	phys_addr_t rd_phys, params_phys, top_delegated;
+	size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr);
+	long rmi_ret;
+	int r;
+
+	realm->ia_bits = VTCR_EL2_IPA(kvm->arch.mmu.vtcr);
+
+	if (WARN_ON(realm->rd))
+		return -EEXIST;
+
+	params = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
+	if (!params)
+		return -ENOMEM;
+
+	rd = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
+	if (!rd)
+		return -ENOMEM;
+
+	rd_phys = virt_to_phys(rd);
+	if (rmi_delegate_page(rd_phys)) {
+		r = -ENXIO;
+		goto free_rd;
+	}
+
+	if (rmi_delegate_range(kvm->arch.mmu.pgd_phys, pgd_size,
+			       &top_delegated)) {
+		r = -ENXIO;
+		goto out_undelegate_tables;
+	}
+
+	params->s2sz = VTCR_EL2_IPA(kvm->arch.mmu.vtcr);
+	params->rtt_level_start = get_start_level(realm);
+	params->rtt_num_start = pgd_size / PAGE_SIZE;
+	params->rtt_base = kvm->arch.mmu.pgd_phys;
+	params->hash_algo = RMI_HASH_SHA_256;
+
+	if (kvm->arch.arm_pmu) {
+		params->pmu_num_ctrs = kvm->arch.nr_pmu_counters;
+		params->flags0 |= RMI_REALM_PARAM_FLAG_PMU;
+	}
+
+	if (kvm_lpa2_is_enabled())
+		params->flags0 |= RMI_REALM_PARAM_FLAG_LPA2;
+
+	params_phys = virt_to_phys(params);
+
+	rmi_ret = rmi_realm_create(rd_phys, params_phys, realm->sro);
+	if (rmi_ret) {
+		r = rmi_ret < 0 ? rmi_ret : -ENXIO;
+		goto out_undelegate_tables;
+	}
+
+	realm->rd = rd;
+	kvm_set_realm_state(kvm, REALM_STATE_NEW);
+
+	return 0;
+
+out_undelegate_tables:
+	if (WARN_ON(rmi_undelegate_range(kvm->arch.mmu.pgd_phys,
+					 top_delegated - kvm->arch.mmu.pgd_phys))) {
+		/* Leak the pages if they cannot be returned */
+		kvm->arch.mmu.pgt = NULL;
+	}
+	if (WARN_ON(rmi_undelegate_page(rd_phys))) {
+		/* Leak the page if it isn't returned */
+		return r;
+	}
+free_rd:
+	free_page((unsigned long)rd);
+	return r;
+}
+
 static void realm_unmap_private_range(struct kvm *kvm,
 				      unsigned long start,
 				      unsigned long end,
@@ -632,6 +709,24 @@ static int realm_set_ipa_state(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
+static int __maybe_unused realm_ensure_created(struct kvm *kvm)
+{
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	switch (kvm_realm_state(kvm)) {
+	case REALM_STATE_NONE:
+		break;
+	case REALM_STATE_NEW:
+		return 0;
+	case REALM_STATE_DEAD:
+		return -ENXIO;
+	default:
+		return -EBUSY;
+	}
+
+	return realm_create_rd(kvm);
+}
+
 static int kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
-- 
2.43.0

[PATCH v16 26/45] KVM: arm64: CCA: Activate realms on first vCPU run

[Steven Price]

Use kvm_arch_vcpu_run_pid_change() to check if this is the first time
the realm guest has run. If this is the first run then activate the
realm.

Signed-off-by: Steven Price <steven.price@arm.com>

---
Changes since v12:
 * Fix commit message
 * Change realm_state checks to be >= REALM_STATE_ACTIVE to avoid a dead
   guest being revived by kvm_activate_realm().
---
 arch/arm64/include/asm/kvm_rmi.h |  1 +
 arch/arm64/kvm/arm.c             |  6 +++++
 arch/arm64/kvm/rmi.c             | 45 ++++++++++++++++++++++++++++++--
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 751659a48be3..90563183a717 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -98,6 +98,7 @@ void kvm_init_rmi(void);
 u32 kvm_rmm_ipa_limit(void);
 
 int kvm_init_realm(struct kvm *kvm);
+int kvm_activate_realm(struct kvm *kvm);
 void kvm_destroy_realm(struct kvm *kvm);
 int kvm_realm_teardown_stage2(struct kvm *kvm);
 void kvm_destroy_rec(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3ad2f1d5b9e2..b7c308817d45 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1034,6 +1034,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 			return ret;
 	}
 
+	if (kvm_is_realm(vcpu->kvm)) {
+		ret = kvm_activate_realm(kvm);
+		if (ret)
+			return ret;
+	}
+
 	mutex_lock(&kvm->arch.config_lock);
 	set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
 	mutex_unlock(&kvm->arch.config_lock);
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 31eedf78a752..c8ec766d3dc0 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -709,7 +709,7 @@ static int realm_set_ipa_state(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
-static int __maybe_unused realm_ensure_created(struct kvm *kvm)
+static int realm_ensure_created(struct kvm *kvm)
 {
 	lockdep_assert_held(&kvm->arch.config_lock);
 
@@ -829,7 +829,7 @@ int noinstr kvm_rec_enter(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
-static int __maybe_unused kvm_create_rec(struct kvm_vcpu *vcpu)
+static int kvm_create_rec(struct kvm_vcpu *vcpu)
 {
 	struct user_pt_regs *vcpu_regs = vcpu_gp_regs(vcpu);
 	unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
@@ -932,6 +932,47 @@ void kvm_destroy_rec(struct kvm_vcpu *vcpu)
 	rec->run_phys = 0;
 }
 
+int kvm_activate_realm(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+	struct kvm_vcpu *vcpu;
+	unsigned long i;
+	int ret;
+
+	if (kvm_realm_state(kvm) >= REALM_STATE_ACTIVE)
+		return 0;
+
+	if (!irqchip_in_kernel(kvm)) {
+		/* Userspace irqchip not yet supported with realms */
+		return -EOPNOTSUPP;
+	}
+
+	guard(mutex)(&kvm->arch.config_lock);
+	/* Check again with the lock held */
+	if (kvm_realm_state(kvm) >= REALM_STATE_ACTIVE)
+		return 0;
+
+	ret = realm_ensure_created(kvm);
+	if (ret)
+		return ret;
+
+	/* Mark state as dead in case we fail */
+	kvm_set_realm_state(kvm, REALM_STATE_DEAD);
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		ret = kvm_create_rec(vcpu);
+		if (ret)
+			return ret;
+	}
+
+	ret = rmi_realm_activate(virt_to_phys(realm->rd));
+	if (ret)
+		return -ENXIO;
+
+	kvm_set_realm_state(kvm, REALM_STATE_ACTIVE);
+	return 0;
+}
+
 void kvm_destroy_realm(struct kvm *kvm)
 {
 	struct realm *realm = &kvm->arch.realm;
-- 
2.43.0

[PATCH v16 27/45] KVM: arm64: CCA: Allow populating initial contents

[Steven Price]

The VMM needs to populate the realm with some data before starting (e.g.
a kernel and initrd). This is measured by the RMM and used as part of
the attestation later on.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Handle negative error codes
Changes since v14:
 * Holding of locks slots_lock and config_lock have been moved up the
   callstack with lockdesp assertions placed in the lower functions.
 * Add overflow check into kvm_arm_rmi_populate().
Changes since v13:
 * Rename realm_create_protected_data_page() to realm_data_map_init().
Changes since v12:
 * The ioctl now updates the structure with the amount populated rather
   than returning this through the ioctl return code.
 * Use the new RMM v2.0 range based RMI calls.
 * Adapt to upstream changes in kvm_gmem_populate().
Changes since v11:
 * The multiplex CAP is gone and there's a new ioctl which makes use of
   the generic kvm_gmem_populate() functionality.
Changes since v7:
 * Improve the error codes.
 * Other minor changes from review.
Changes since v6:
 * Handle host potentially having a larger page size than the RMM
   granule.
 * Drop historic "par" (protected address range) from
   populate_par_region() - it doesn't exist within the current
   architecture.
 * Add a cond_resched() call in kvm_populate_realm().
Changes since v5:
 * Refactor to use PFNs rather than tracking struct page in
   realm_create_protected_data_page().
 * Pull changes from a later patch (in the v5 series) for accessing
   pages from a guest memfd.
 * Do the populate in chunks to avoid holding locks for too long and
   triggering RCU stall warnings.
---
 arch/arm64/include/asm/kvm_rmi.h |   4 ++
 arch/arm64/kvm/Kconfig           |   1 +
 arch/arm64/kvm/arm.c             |  13 ++++
 arch/arm64/kvm/rmi.c             | 119 +++++++++++++++++++++++++++++++
 4 files changed, 137 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 90563183a717..03f8bd2d13a2 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -108,6 +108,10 @@ int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
 int kvm_rec_handle_request(struct kvm_vcpu *vcpu);
 bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret);
 
+struct kvm_arm_rmi_populate;
+
+int kvm_arm_rmi_populate(struct kvm *kvm,
+			 struct kvm_arm_rmi_populate *arg);
 void kvm_realm_unmap_range(struct kvm *kvm,
 			   unsigned long ipa,
 			   unsigned long size,
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 189e8ad78b22..83b95e836b4d 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -37,6 +37,7 @@ menuconfig KVM
 	select SCHED_INFO
 	select GUEST_PERF_EVENTS if PERF_EVENTS
 	select KVM_GUEST_MEMFD
+	select HAVE_KVM_ARCH_GMEM_POPULATE
 	select ARM_RMM
 	help
 	  Support hosting virtualized guest machines.
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index b7c308817d45..f1b26b263bf0 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2154,6 +2154,19 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 			return -EFAULT;
 		return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range);
 	}
+	case KVM_ARM_RMI_POPULATE: {
+		struct kvm_arm_rmi_populate req;
+		int ret;
+
+		if (!kvm_is_realm(kvm))
+			return -ENXIO;
+		if (copy_from_user(&req, argp, sizeof(req)))
+			return -EFAULT;
+		ret = kvm_arm_rmi_populate(kvm, &req);
+		if (copy_to_user(argp, &req, sizeof(req)))
+			return -EFAULT;
+		return ret;
+	}
 	default:
 		return -EINVAL;
 	}
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index c8ec766d3dc0..d18c241f7eb2 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -609,6 +609,76 @@ void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start,
 		realm_unmap_private_range(kvm, start, end, may_block);
 }
 
+static int realm_data_map_init(struct kvm *kvm, unsigned long ipa,
+			       kvm_pfn_t dst_pfn, kvm_pfn_t src_pfn,
+			       unsigned long flags)
+{
+	struct realm *realm = &kvm->arch.realm;
+	phys_addr_t rd = virt_to_phys(realm->rd);
+	phys_addr_t dst_phys, src_phys;
+	long ret;
+
+	lockdep_assert_held(&kvm->slots_lock);
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	dst_phys = __pfn_to_phys(dst_pfn);
+	src_phys = __pfn_to_phys(src_pfn);
+
+	if (rmi_delegate_page(dst_phys))
+		return -ENXIO;
+
+retry:
+	ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, flags);
+	if (ret >= 0 && RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+		/* Create missing RTTs and retry */
+		int level = RMI_RETURN_INDEX(ret);
+
+		KVM_BUG_ON(level >= KVM_PGTABLE_LAST_LEVEL, kvm);
+
+		ret = realm_create_rtt_levels(realm, ipa, level,
+					      level + 1, NULL);
+		if (!ret)
+			goto retry;
+	}
+
+	if (ret && WARN_ON(rmi_undelegate_page(dst_phys))) {
+		/* Leak the page if the undelegate fails */
+		get_page(pfn_to_page(dst_pfn));
+	}
+
+	return ret <= 0 ? ret : -ENXIO;
+}
+
+static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
+			      struct page *src_page, void *opaque)
+{
+	unsigned long data_flags = *(unsigned long *)opaque;
+	phys_addr_t ipa = gfn_to_gpa(gfn);
+
+	return realm_data_map_init(kvm, ipa, pfn, page_to_pfn(src_page),
+				   data_flags);
+}
+
+static long populate_region(struct kvm *kvm,
+			    gfn_t base_gfn,
+			    unsigned long pages,
+			    u64 uaddr,
+			    unsigned long data_flags)
+{
+	long ret = 0;
+
+	lockdep_assert_held(&kvm->slots_lock);
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	if (!uaddr)
+		return -EINVAL;
+
+	ret = kvm_gmem_populate(kvm, base_gfn, u64_to_user_ptr(uaddr), pages,
+				false, populate_region_cb, &data_flags);
+
+	return ret;
+}
+
 enum ripas_action {
 	RIPAS_INIT,
 	RIPAS_SET,
@@ -727,6 +797,55 @@ static int realm_ensure_created(struct kvm *kvm)
 	return realm_create_rd(kvm);
 }
 
+int kvm_arm_rmi_populate(struct kvm *kvm,
+			 struct kvm_arm_rmi_populate *args)
+{
+	unsigned long data_flags = 0;
+	unsigned long ipa_start = args->base;
+	unsigned long ipa_end = ipa_start + args->size;
+	long pages_populated;
+	int ret;
+
+	if (args->reserved ||
+	    (args->flags & ~KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) ||
+	    args->base + args->size < args->base ||
+	    !IS_ALIGNED(ipa_start, PAGE_SIZE) ||
+	    !IS_ALIGNED(ipa_end, PAGE_SIZE) ||
+	    !IS_ALIGNED(args->source_uaddr, PAGE_SIZE))
+		return -EINVAL;
+
+	if (args->flags & KVM_ARM_RMI_POPULATE_FLAGS_MEASURE)
+		data_flags |= RMI_MEASURE_CONTENT;
+
+	mutex_lock(&kvm->slots_lock);
+	mutex_lock(&kvm->arch.config_lock);
+
+	ret = realm_ensure_created(kvm);
+	if (ret)
+		goto out_unlock;
+
+	if (args->size == 0)
+		goto out_unlock;
+
+	pages_populated = populate_region(kvm, gpa_to_gfn(ipa_start),
+					  args->size >> PAGE_SHIFT,
+					  args->source_uaddr, data_flags);
+
+	if (pages_populated < 0) {
+		ret = pages_populated;
+		goto out_unlock;
+	}
+
+	args->size -= pages_populated << PAGE_SHIFT;
+	args->source_uaddr += pages_populated << PAGE_SHIFT;
+	args->base += pages_populated << PAGE_SHIFT;
+
+out_unlock:
+	mutex_unlock(&kvm->arch.config_lock);
+	mutex_unlock(&kvm->slots_lock);
+	return ret;
+}
+
 static int kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
 {
 	struct kvm *kvm = vcpu->kvm;
-- 
2.43.0

[PATCH v16 28/45] KVM: arm64: CCA: Set RIPAS of initial memslots

[Steven Price]

The memory which the realm guest accesses must be set to RIPAS_RAM.
Iterate over the memslots and set all gmem memslots to RIPAS_RAM.

Signed-off-by: Steven Price <steven.price@arm.com>
---
New patch for v12.
---
 arch/arm64/kvm/rmi.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index d18c241f7eb2..4f362fd21477 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -779,6 +779,14 @@ static int realm_set_ipa_state(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
+static int realm_init_ipa_state(struct kvm *kvm,
+				unsigned long gfn,
+				unsigned long pages)
+{
+	return ripas_change(kvm, NULL, gfn_to_gpa(gfn), gfn_to_gpa(gfn + pages),
+			    RIPAS_INIT, NULL);
+}
+
 static int realm_ensure_created(struct kvm *kvm)
 {
 	lockdep_assert_held(&kvm->arch.config_lock);
@@ -797,6 +805,32 @@ static int realm_ensure_created(struct kvm *kvm)
 	return realm_create_rd(kvm);
 }
 
+static int set_ripas_of_protected_regions(struct kvm *kvm)
+{
+	struct kvm_memslots *slots;
+	struct kvm_memory_slot *memslot;
+	int idx, bkt;
+	int ret = 0;
+
+	lockdep_assert_held(&kvm->arch.config_lock);
+
+	idx = srcu_read_lock(&kvm->srcu);
+
+	slots = kvm_memslots(kvm);
+	kvm_for_each_memslot(memslot, bkt, slots) {
+		if (!kvm_slot_has_gmem(memslot))
+			continue;
+
+		ret = realm_init_ipa_state(kvm, memslot->base_gfn,
+					   memslot->npages);
+		if (ret)
+			break;
+	}
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	return ret;
+}
+
 int kvm_arm_rmi_populate(struct kvm *kvm,
 			 struct kvm_arm_rmi_populate *args)
 {
@@ -1084,6 +1118,10 @@ int kvm_activate_realm(struct kvm *kvm)
 			return ret;
 	}
 
+	ret = set_ripas_of_protected_regions(kvm);
+	if (ret)
+		return ret;
+
 	ret = rmi_realm_activate(virt_to_phys(realm->rd));
 	if (ret)
 		return -ENXIO;
-- 
2.43.0

[PATCH v16 29/45] KVM: arm64: CCA: Support runtime faulting of memory

[Steven Price]

At runtime if the realm guest accesses memory which hasn't yet been
mapped then KVM needs to either populate the region or fault the guest.

For memory in the lower (protected) region of IPA a fresh page is
provided to the RMM which will zero the contents. For memory in the
upper (shared) region of IPA, the memory from the memslot is mapped
into the realm VM non secure.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Handle negative error codes.
Changes since v13:
 * Numerous changes due to rebasing.
 * Fix addr_range_desc() to encode the correct block size.
Changes since v12:
 * Switch to RMM v2.0 range based APIs.
Changes since v11:
 * Adapt to upstream changes.
Changes since v10:
 * RME->RMI renaming.
 * Adapt to upstream gmem changes.
Changes since v9:
 * Fix call to kvm_stage2_unmap_range() in kvm_free_stage2_pgd() to set
   may_block to avoid stall warnings.
 * Minor coding style fixes.
Changes since v8:
 * Propagate the may_block flag.
 * Minor comments and coding style changes.
Changes since v7:
 * Remove redundant WARN_ONs for realm_create_rtt_levels() - it will
   internally WARN when necessary.
Changes since v6:
 * Handle PAGE_SIZE being larger than RMM granule size.
 * Some minor renaming following review comments.
Changes since v5:
 * Reduce use of struct page in preparation for supporting the RMM
   having a different page size to the host.
 * Handle a race when delegating a page where another CPU has faulted on
   a the same page (and already delegated the physical page) but not yet
   mapped it. In this case simply return to the guest to either use the
   mapping from the other CPU (or refault if the race is lost).
 * The changes to populate_par_region() are moved into the previous
   patch where they belong.
Changes since v4:
 * Code cleanup following review feedback.
 * Drop the PTE_SHARED bit when creating unprotected page table entries.
   This is now set by the RMM and the host has no control of it and the
   spec requires the bit to be set to zero.
Changes since v2:
 * Avoid leaking memory if failing to map it in the realm.
 * Correctly mask RTT based on LPA2 flag (see rtt_get_phys()).
 * Adapt to changes in previous patches.
---
 arch/arm64/include/asm/kvm_emulate.h |   8 +
 arch/arm64/include/asm/kvm_rmi.h     |   5 +
 arch/arm64/kvm/mmu.c                 |  97 ++++++++----
 arch/arm64/kvm/rmi.c                 | 220 +++++++++++++++++++++++++++
 4 files changed, 304 insertions(+), 26 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 2e69fe494716..8b6f9d26b5d8 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -712,6 +712,14 @@ static inline bool kvm_realm_is_created(struct kvm *kvm)
 	return kvm_is_realm(kvm) && kvm_realm_state(kvm) != REALM_STATE_NONE;
 }
 
+static inline gpa_t kvm_gpa_from_fault(struct kvm *kvm, phys_addr_t ipa)
+{
+	if (!kvm_is_realm(kvm))
+		return ipa;
+
+	return ipa & ~BIT(kvm->arch.realm.ia_bits - 1);
+}
+
 static inline bool vcpu_is_rec(const struct kvm_vcpu *vcpu)
 {
 	return kvm_is_realm(vcpu->kvm);
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 03f8bd2d13a2..967c0a6e8e9c 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -6,6 +6,7 @@
 #ifndef __ASM_KVM_RMI_H
 #define __ASM_KVM_RMI_H
 
+#include <asm/kvm_pgtable.h>
 #include <linux/arm-smccc-rmi.h>
 
 /**
@@ -117,6 +118,10 @@ void kvm_realm_unmap_range(struct kvm *kvm,
 			   unsigned long size,
 			   bool unmap_private,
 			   bool may_block);
+int realm_map_ipa(struct kvm *kvm, phys_addr_t ipa,
+		  kvm_pfn_t pfn, unsigned long map_size,
+		  enum kvm_pgtable_prot prot,
+		  struct kvm_mmu_memory_cache *memcache);
 
 static inline bool kvm_realm_is_private_address(struct realm *realm,
 						unsigned long addr)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index dcc2ab08d0e4..79119cb136b0 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -334,8 +334,15 @@ static void __unmap_stage2_range(struct kvm_s2_mmu *mmu, phys_addr_t start, u64
 
 	lockdep_assert_held_write(&kvm->mmu_lock);
 	WARN_ON(size & ~PAGE_MASK);
-	WARN_ON(stage2_apply_range(mmu, start, end, KVM_PGT_FN(kvm_pgtable_stage2_unmap),
-				   may_block));
+
+	if (kvm_is_realm(kvm)) {
+		kvm_realm_unmap_range(kvm, start, size, !only_shared,
+				      may_block);
+	} else {
+		WARN_ON(stage2_apply_range(mmu, start, end,
+					   KVM_PGT_FN(kvm_pgtable_stage2_unmap),
+					   may_block));
+	}
 }
 
 void kvm_stage2_unmap_range(struct kvm_s2_mmu *mmu, phys_addr_t start,
@@ -358,7 +365,10 @@ static void stage2_flush_memslot(struct kvm *kvm,
 	phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
 	phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
 
-	kvm_stage2_flush_range(&kvm->arch.mmu, addr, end);
+	if (kvm_is_realm(kvm))
+		kvm_realm_unmap_range(kvm, addr, end - addr, false, true);
+	else
+		kvm_stage2_flush_range(&kvm->arch.mmu, addr, end);
 }
 
 /**
@@ -1137,6 +1147,10 @@ void stage2_unmap_vm(struct kvm *kvm)
 	struct kvm_memory_slot *memslot;
 	int idx, bkt;
 
+	/* For realms this is handled by the RMM so nothing to do here */
+	if (kvm_is_realm(kvm))
+		return;
+
 	idx = srcu_read_lock(&kvm->srcu);
 	mmap_read_lock(current->mm);
 	write_lock(&kvm->mmu_lock);
@@ -1641,18 +1655,20 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 	bool perm_fault = kvm_vcpu_trap_is_permission_fault(s2fd->vcpu);
 	enum kvm_pgtable_walk_flags flags = KVM_PGTABLE_WALK_SHARED;
 	enum kvm_pgtable_prot prot = KVM_PGTABLE_PROT_R;
-	struct kvm_pgtable *pgt = s2fd->vcpu->arch.hw_mmu->pgt;
+	struct kvm_vcpu *vcpu = s2fd->vcpu;
+	struct kvm_pgtable *pgt = vcpu->arch.hw_mmu->pgt;
+	gpa_t gpa = kvm_gpa_from_fault(vcpu->kvm, s2fd->fault_ipa);
 	unsigned long mmu_seq;
 	struct page *page;
-	struct kvm *kvm = s2fd->vcpu->kvm;
+	struct kvm *kvm = vcpu->kvm;
 	void *memcache = NULL;
 	kvm_pfn_t pfn;
 	gfn_t gfn;
 	int ret;
 
 	if (!perm_fault) {
-		memcache = get_mmu_memcache(s2fd->vcpu);
-		ret = topup_mmu_memcache(s2fd->vcpu, memcache);
+		memcache = get_mmu_memcache(vcpu);
+		ret = topup_mmu_memcache(vcpu, memcache);
 		if (ret)
 			return ret;
 	}
@@ -1660,10 +1676,10 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 	if (s2fd->nested)
 		gfn = kvm_s2_trans_output(s2fd->nested) >> PAGE_SHIFT;
 	else
-		gfn = s2fd->fault_ipa >> PAGE_SHIFT;
+		gfn = gpa >> PAGE_SHIFT;
 
-	write_fault = kvm_is_write_fault(s2fd->vcpu);
-	exec_fault = kvm_vcpu_trap_is_exec_fault(s2fd->vcpu);
+	write_fault = kvm_is_write_fault(vcpu);
+	exec_fault = kvm_vcpu_trap_is_exec_fault(vcpu);
 
 	VM_WARN_ON_ONCE(write_fault && exec_fault);
 
@@ -1673,7 +1689,7 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 
 	ret = kvm_gmem_get_pfn(kvm, s2fd->memslot, gfn, &pfn, &page, NULL);
 	if (ret) {
-		kvm_prepare_memory_fault_exit(s2fd->vcpu, s2fd->fault_ipa, PAGE_SIZE,
+		kvm_prepare_memory_fault_exit(vcpu, gpa, PAGE_SIZE,
 					      write_fault, exec_fault, false);
 		return ret;
 	}
@@ -1693,7 +1709,14 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 	kvm_fault_lock(kvm);
 	if (mmu_invalidate_retry(kvm, mmu_seq)) {
 		ret = -EAGAIN;
-		goto out_unlock;
+		goto out_release_page;
+	}
+
+	if (kvm_is_realm(kvm)) {
+		prot &= ~KVM_PGTABLE_PROT_X;
+		ret = realm_map_ipa(kvm, s2fd->fault_ipa, pfn,
+				    PAGE_SIZE, prot, memcache);
+		goto out_release_page;
 	}
 
 	if (perm_fault) {
@@ -1710,7 +1733,7 @@ static int gmem_abort(const struct kvm_s2_fault_desc *s2fd)
 							 memcache, flags);
 	}
 
-out_unlock:
+out_release_page:
 	kvm_release_faultin_page(kvm, page, !!ret, prot & KVM_PGTABLE_PROT_W);
 	kvm_fault_unlock(kvm);
 
@@ -1896,7 +1919,7 @@ static int kvm_s2_fault_get_vma_info(const struct kvm_s2_fault_desc *s2fd,
 	 * mapping size to ensure we find the right PFN and lay down the
 	 * mapping in the right place.
 	 */
-	s2vi->gfn = ALIGN_DOWN(s2fd->fault_ipa, s2vi->vma_pagesize) >> PAGE_SHIFT;
+	s2vi->gfn = kvm_gpa_from_fault(kvm, ALIGN_DOWN(s2fd->fault_ipa, s2vi->vma_pagesize)) >> PAGE_SHIFT;
 
 	s2vi->mte_allowed = kvm_vma_mte_allowed(vma);
 
@@ -2092,12 +2115,15 @@ static int kvm_s2_fault_map(const struct kvm_s2_fault_desc *s2fd,
 	if (!perm_fault_granule && !s2vi->map_non_cacheable && kvm_has_mte(kvm))
 		sanitise_mte_tags(kvm, pfn, mapping_size);
 
-	/*
-	 * Under the premise of getting a FSC_PERM fault, we just need to relax
-	 * permissions only if mapping_size equals perm_fault_granule. Otherwise,
-	 * kvm_pgtable_stage2_map() should be called to change block size.
-	 */
-	if (mapping_size == perm_fault_granule) {
+	if (kvm_is_realm(kvm)) {
+		ret = realm_map_ipa(kvm, s2fd->fault_ipa, pfn, mapping_size,
+				    prot, memcache);
+	} else if (mapping_size == perm_fault_granule) {
+		/*
+		 * Under the premise of getting a FSC_PERM fault, we just need to relax
+		 * permissions only if mapping_size equals perm_fault_granule. Otherwise,
+		 * kvm_pgtable_stage2_map() should be called to change block size.
+		 */
 		/*
 		 * Drop the SW bits in favour of those stored in the
 		 * PTE, which will be preserved.
@@ -2263,6 +2289,13 @@ int kvm_handle_guest_sea(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static bool shared_ipa_fault(struct kvm *kvm, phys_addr_t fault_ipa)
+{
+	gpa_t gpa = kvm_gpa_from_fault(kvm, fault_ipa);
+
+	return (gpa != fault_ipa);
+}
+
 /**
  * kvm_handle_guest_abort - handles all 2nd stage aborts
  * @vcpu:	the VCPU pointer
@@ -2373,8 +2406,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 		nested = &nested_trans;
 	}
 
-	gfn = ipa >> PAGE_SHIFT;
+	gfn = kvm_gpa_from_fault(vcpu->kvm, ipa) >> PAGE_SHIFT;
 	memslot = gfn_to_memslot(vcpu->kvm, gfn);
+
 	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
 	write_fault = kvm_is_write_fault(vcpu);
 	if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
@@ -2417,7 +2451,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 		 * of the page size.
 		 */
 		ipa |= FAR_TO_FIPA_OFFSET(kvm_vcpu_get_hfar(vcpu));
-		ret = io_mem_abort(vcpu, ipa);
+		ret = io_mem_abort(vcpu, kvm_gpa_from_fault(vcpu->kvm, ipa));
 		goto out_unlock;
 	}
 
@@ -2445,7 +2479,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu)
 				!write_fault &&
 				!kvm_vcpu_trap_is_exec_fault(vcpu));
 
-		if (kvm_slot_has_gmem(memslot))
+		if (kvm_slot_has_gmem(memslot) &&
+		    (kvm_memslot_is_gmem_only(memslot) ||
+		     !shared_ipa_fault(vcpu->kvm, fault_ipa)))
 			ret = gmem_abort(&s2fd);
 		else
 			ret = user_mem_abort(&s2fd);
@@ -2482,6 +2518,10 @@ bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 	if (!kvm->arch.mmu.pgt || kvm_vm_is_protected(kvm))
 		return false;
 
+	/* We don't support aging for Realms */
+	if (kvm_is_realm(kvm))
+		return true;
+
 	return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
 						   range->start << PAGE_SHIFT,
 						   size, true);
@@ -2498,6 +2538,10 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 	if (!kvm->arch.mmu.pgt || kvm_vm_is_protected(kvm))
 		return false;
 
+	/* We don't support aging for Realms */
+	if (kvm_is_realm(kvm))
+		return true;
+
 	return KVM_PGT_FN(kvm_pgtable_stage2_test_clear_young)(kvm->arch.mmu.pgt,
 						   range->start << PAGE_SHIFT,
 						   size, false);
@@ -2677,10 +2721,11 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
 		return -EFAULT;
 
 	/*
-	 * Only support guest_memfd backed memslots with mappable memory, since
-	 * there aren't any CoCo VMs that support only private memory on arm64.
+	 * Only support guest_memfd backed memslots with mappable memory,
+	 * unless the guest is a CCA realm guest.
 	 */
-	if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new))
+	if (kvm_slot_has_gmem(new) && !kvm_memslot_is_gmem_only(new) &&
+	    !kvm_is_realm(kvm))
 		return -EINVAL;
 
 	hva = new->userspace_addr;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 4f362fd21477..3ef185bc8210 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -649,6 +649,226 @@ static int realm_data_map_init(struct kvm *kvm, unsigned long ipa,
 	return ret <= 0 ? ret : -ENXIO;
 }
 
+static unsigned long addr_range_desc(unsigned long phys, unsigned long size,
+				     unsigned long state)
+{
+	unsigned long count = 1;
+	unsigned long out;
+	int rmi_size;
+
+	for (rmi_size = KVM_PGTABLE_LAST_LEVEL; rmi_size >= 0; rmi_size--) {
+		unsigned long entry_size = rmi_range_entry_size(rmi_size);
+
+		if (size == entry_size)
+			break;
+		if (size > entry_size) {
+			rmi_size = -1;
+			break;
+		}
+	}
+
+	if (rmi_size < 0) {
+		/*
+		 * Only support mapping at the page level granularity when
+		 * it's an unusual length. This should get us back onto a larger
+		 * block size for the subsequent mappings.
+		 */
+		rmi_size = 0;
+		count = MIN(size >> PAGE_SHIFT, PTRS_PER_PTE - 1);
+	}
+
+	WARN_ON(phys & ~PAGE_MASK);
+
+	out = FIELD_PREP(RMI_ADDR_RANGE_SIZE_MASK, rmi_size) |
+	      FIELD_PREP(RMI_ADDR_RANGE_COUNT_MASK, count) |
+	      FIELD_PREP(RMI_ADDR_RANGE_STATE_MASK, state);
+	out |= phys & PAGE_MASK;
+
+	return out;
+}
+
+static int realm_map_protected(struct kvm *kvm,
+			       unsigned long ipa,
+			       kvm_pfn_t pfn,
+			       unsigned long map_size,
+			       struct kvm_mmu_memory_cache *memcache)
+{
+	struct realm *realm = &kvm->arch.realm;
+	phys_addr_t phys = __pfn_to_phys(pfn);
+	phys_addr_t base_phys = phys;
+	phys_addr_t rd = virt_to_phys(realm->rd);
+	phys_addr_t delegated_phys;
+	unsigned long base_ipa = ipa;
+	unsigned long ipa_top;
+	long ret = 0;
+
+	if (WARN_ON(!IS_ALIGNED(map_size, PAGE_SIZE) ||
+		    !IS_ALIGNED(ipa, map_size)))
+		return -EINVAL;
+
+	if (rmi_delegate_range(phys, map_size, &delegated_phys)) {
+		if (delegated_phys == phys) {
+			/*
+			 * It's likely we raced with another VCPU on the same
+			 * fault. Assume the other VCPU has handled the fault
+			 * and return to the guest.
+			 */
+			return 0;
+		}
+		/* Partial delegation - map as much as we can */
+		map_size = delegated_phys - phys;
+	}
+
+	ipa_top = ipa + map_size;
+
+	while (ipa < ipa_top) {
+		unsigned long flags = RMI_ADDR_TYPE_SINGLE;
+		unsigned long range_desc = addr_range_desc(phys, ipa_top - ipa,
+							   RMI_OP_MEM_DELEGATED);
+		unsigned long out_top;
+
+		ret = rmi_rtt_data_map(rd, ipa, ipa_top, flags, range_desc,
+				       &out_top);
+		if (ret < 0)
+			goto err_undelegate;
+
+		if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+			/* Create missing RTTs and retry */
+			int level = RMI_RETURN_INDEX(ret);
+
+			if (WARN_ON(level >= KVM_PGTABLE_LAST_LEVEL))
+				goto err_undelegate;
+			ret = realm_create_rtt_levels(realm, ipa, level,
+						      level + 1,
+						      memcache);
+			if (ret)
+				goto err_undelegate;
+
+			continue;
+		}
+
+		if (WARN_ON(ret))
+			goto err_undelegate;
+
+		phys += out_top - ipa;
+		ipa = out_top;
+	}
+
+	return 0;
+
+err_undelegate:
+	realm_unmap_private_range(kvm, base_ipa, ipa, true);
+	if (WARN_ON(rmi_undelegate_range(base_phys, map_size))) {
+		/* Page can't be returned to NS world so is lost */
+		get_page(phys_to_page(base_phys));
+	}
+	return ret < 0 ? ret : -ENXIO;
+}
+
+static int realm_map_non_secure(struct kvm *kvm,
+				unsigned long ipa,
+				kvm_pfn_t pfn,
+				unsigned long size,
+				enum kvm_pgtable_prot prot,
+				struct kvm_mmu_memory_cache *memcache)
+{
+	struct realm *realm = &kvm->arch.realm;
+	unsigned long attr, flags = 0;
+	phys_addr_t rd = virt_to_phys(realm->rd);
+	phys_addr_t phys = __pfn_to_phys(pfn);
+	unsigned long ipa_top = ipa + size;
+	long ret;
+
+	if (WARN_ON(!IS_ALIGNED(size, PAGE_SIZE)))
+		return -EINVAL;
+
+	switch (prot & (KVM_PGTABLE_PROT_DEVICE | KVM_PGTABLE_PROT_NORMAL_NC)) {
+	case KVM_PGTABLE_PROT_DEVICE | KVM_PGTABLE_PROT_NORMAL_NC:
+		return -EINVAL;
+	case KVM_PGTABLE_PROT_DEVICE:
+		attr = MT_S2_FWB_DEVICE_nGnRE;
+		break;
+	case KVM_PGTABLE_PROT_NORMAL_NC:
+		attr = MT_S2_FWB_NORMAL_NC;
+		break;
+	default:
+		attr = MT_S2_FWB_NORMAL;
+	}
+
+	flags |= FIELD_PREP(RMI_RTT_UNPROT_MAP_FLAGS_MEMATTR, attr);
+
+	if (prot & KVM_PGTABLE_PROT_R)
+		flags |= FIELD_PREP(RMI_RTT_UNPROT_MAP_FLAGS_S2AP, RMI_S2AP_DIRECT_READ);
+	if (prot & KVM_PGTABLE_PROT_W)
+		flags |= FIELD_PREP(RMI_RTT_UNPROT_MAP_FLAGS_S2AP, RMI_S2AP_DIRECT_WRITE);
+
+	flags |= RMI_ADDR_TYPE_SINGLE;
+
+	while (ipa < ipa_top) {
+		unsigned long range_desc = addr_range_desc(phys, ipa_top - ipa,
+							   RMI_OP_MEM_UNDELEGATED);
+		unsigned long out_top;
+
+		ret = rmi_rtt_unprot_map(rd, ipa, ipa_top, flags, range_desc,
+					 &out_top);
+		if (ret < 0)
+			return ret;
+
+		if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
+			/* Create missing RTTs and retry */
+			int level = RMI_RETURN_INDEX(ret);
+			int req_level = find_map_level(realm, ipa, ipa_top);
+
+			/*
+			 * There already exists a mapping at the level. May be
+			 * we are relaxing a permission for the given range ?
+			 */
+			if (level >= req_level) {
+				realm_unmap_shared_range(kvm, ipa, ipa_top, true);
+				continue;
+			}
+
+			ret = realm_create_rtt_levels(realm, ipa, level,
+						      req_level,
+						      memcache);
+			if (ret)
+				return ret;
+
+			ret = rmi_rtt_unprot_map(rd, ipa, ipa_top, flags,
+						 range_desc, &out_top);
+			if (ret < 0)
+				return ret;
+		}
+
+		if (ret && RMI_RETURN_STATUS(ret) != RMI_ERROR_RTT)
+			return ret;
+
+		phys += out_top - ipa;
+		ipa = out_top;
+	}
+
+	return 0;
+}
+
+int realm_map_ipa(struct kvm *kvm, phys_addr_t ipa,
+		  kvm_pfn_t pfn, unsigned long map_size,
+		  enum kvm_pgtable_prot prot,
+		  struct kvm_mmu_memory_cache *memcache)
+{
+	struct realm *realm = &kvm->arch.realm;
+
+	ipa = ALIGN_DOWN(ipa, map_size);
+	if (!kvm_realm_is_private_address(realm, ipa)) {
+		return realm_map_non_secure(kvm, ipa, pfn, map_size, prot,
+					    memcache);
+	}
+
+	/* It's impossible to map protected pages read-only. */
+	if (WARN_ON(!(prot & KVM_PGTABLE_PROT_W)))
+		return -EFAULT;
+	return realm_map_protected(kvm, ipa, pfn, map_size, memcache);
+}
+
 static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
 			      struct page *src_page, void *opaque)
 {
-- 
2.43.0

[PATCH v16 30/45] KVM: arm64: CCA: Handle realm vCPU load

[Steven Price]

When loading a realm VCPU much of the work is handled by the RMM so only
some of the actions are required. Rearrange kvm_arch_vcpu_load()
slightly so we can bail out early for a realm guest.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/arm.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index f1b26b263bf0..96e536d2dda8 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -707,7 +707,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	struct kvm_s2_mmu *mmu;
 	int *last_ran;
 
-	if (is_protected_kvm_enabled())
+	if (is_protected_kvm_enabled() || kvm_is_realm(vcpu->kvm))
 		goto nommu;
 
 	if (vcpu_has_nv(vcpu))
@@ -751,12 +751,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	kvm_vgic_load(vcpu);
 	kvm_vcpu_load_debug(vcpu);
 	kvm_vcpu_load_fgt(vcpu);
-	if (has_vhe())
-		kvm_vcpu_load_vhe(vcpu);
-	kvm_arch_vcpu_load_fp(vcpu);
-	kvm_vcpu_pmu_restore_guest(vcpu);
-	if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
-		kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
 
 	if (kvm_vcpu_should_clear_twe(vcpu))
 		vcpu->arch.hcr_el2 &= ~HCR_TWE;
@@ -778,6 +772,17 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 			     &vcpu->arch.vgic_cpu.vgic_v3);
 	}
 
+	/* No additional state needs to be loaded on Realmed VMs */
+	if (vcpu_is_rec(vcpu))
+		return;
+
+	if (has_vhe())
+		kvm_vcpu_load_vhe(vcpu);
+	kvm_arch_vcpu_load_fp(vcpu);
+	kvm_vcpu_pmu_restore_guest(vcpu);
+	if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
+		kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
+
 	if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
 		vcpu_set_on_unsupported_cpu(vcpu);
 
-- 
2.43.0

[PATCH v16 31/45] KVM: arm64: CCA: Validate register access for Realm VMs

[Steven Price]

The RMM only allows setting the GPRS (x0-x30) and PC for a realm
guest. Check this in kvm_arm_set_reg() so that the VMM can receive a
suitable error return if other registers are written to.

The RMM makes similar restrictions for reading of the guest's registers
(this is *confidential* compute after all), however we don't impose the
restriction here. This allows the VMM to read (stale) values from the
registers which might be useful to read back the initial values even if
the RMM doesn't provide the latest version. For migration of a realm VM,
a new interface will be needed so that the VMM can receive an
(encrypted) blob of the VM's state.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v5:
 * Upper GPRS can be set as part of a HOST_CALL return, so fix up the
   test to allow them.
---
 arch/arm64/kvm/guest.c | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index b01d6622b872..3e970c4f6214 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -73,6 +73,25 @@ static u64 core_reg_offset_from_id(u64 id)
 	return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
 }
 
+static bool kvm_realm_validate_core_reg(u64 off)
+{
+	/*
+	 * Note that GPRs can only sometimes be controlled by the VMM.
+	 * For PSCI only X0-X6 are used, higher registers are ignored (restored
+	 * from the REC).
+	 * For HOST_CALL all of X0-X30 are copied to the RsiHostCall structure.
+	 * For emulated MMIO X0 is always used.
+	 * PC can only be set before the realm is activated.
+	 */
+	switch (off) {
+	case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
+	     KVM_REG_ARM_CORE_REG(regs.regs[30]):
+	case KVM_REG_ARM_CORE_REG(regs.pc):
+		return true;
+	}
+	return false;
+}
+
 static int core_reg_size_from_offset(const struct kvm_vcpu *vcpu, u64 off)
 {
 	int size;
@@ -716,12 +735,34 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	return kvm_arm_sys_reg_get_reg(vcpu, reg);
 }
 
+/*
+ * The RMI ABI only enables setting some GPRs and PC. The selection of GPRs
+ * that are available depends on the Realm state and the reason for the last
+ * exit.  All other registers are reset to architectural or otherwise defined
+ * reset values by the RMM, except for a few configuration fields that
+ * correspond to Realm parameters.
+ */
+static bool validate_realm_set_reg(struct kvm_vcpu *vcpu,
+				   const struct kvm_one_reg *reg)
+{
+	if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_CORE) {
+		u64 off = core_reg_offset_from_id(reg->id);
+
+		return kvm_realm_validate_core_reg(off);
+	}
+
+	return false;
+}
+
 int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 {
 	/* We currently use nothing arch-specific in upper 32 bits */
 	if ((reg->id & ~KVM_REG_SIZE_MASK) >> 32 != KVM_REG_ARM64 >> 32)
 		return -EINVAL;
 
+	if (kvm_is_realm(vcpu->kvm) && !validate_realm_set_reg(vcpu, reg))
+		return -EINVAL;
+
 	switch (reg->id & KVM_REG_ARM_COPROC_MASK) {
 	case KVM_REG_ARM_CORE:	return set_core_reg(vcpu, reg);
 	case KVM_REG_ARM_FW:
-- 
2.43.0

[PATCH v16 32/45] KVM: arm64: CCA: Handle Realm PSCI requests

[Steven Price]

Some PSCI commands cause a REC exit and the host has to call
RMI_PSCI_COMPLETE to provide the status value to return to the guest.

Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Adapt to new exit handling.
Changes since v14:
 * Dropped the support for providing the target REC for a PSCI call (as
   per v2.0-bet2 spec).
Changes since v13:
 * The ioctl KVM_ARM_VCPU_RMI_PSCI_COMPLETE has gone. The RMI call is
   made automatically just before entering the REC again.
Changes since v12:
 * Change return code for non-realms to -ENXIO to better represent that
   the ioctl is invalid for non-realms (checkpatch is insistent that
   "ENOSYS means 'invalid syscall nr' and nothing else").
Changes since v11:
 * RMM->RMI renaming.
Changes since v6:
 * Use vcpu_is_rec() rather than kvm_is_realm(vcpu->kvm).
 * Minor renaming/formatting fixes.
---
 arch/arm64/include/asm/kvm_rmi.h |  2 ++
 arch/arm64/kvm/rmi.c             | 38 ++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 967c0a6e8e9c..0fb685004d5c 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -123,6 +123,8 @@ int realm_map_ipa(struct kvm *kvm, phys_addr_t ipa,
 		  enum kvm_pgtable_prot prot,
 		  struct kvm_mmu_memory_cache *memcache);
 
+int realm_psci_complete(struct kvm_vcpu *source, unsigned long status);
+
 static inline bool kvm_realm_is_private_address(struct realm *realm,
 						unsigned long addr)
 {
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 3ef185bc8210..3f31ad25680f 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2023-2026 ARM Ltd.
  */
 
+#include <uapi/linux/psci.h>
 #include <linux/kvm_host.h>
 
 #include <asm/kvm_emulate.h>
@@ -120,6 +121,17 @@ static void free_rtt(phys_addr_t phys)
 	kvm_account_pgtable_pages(phys_to_virt(phys), -1);
 }
 
+int realm_psci_complete(struct kvm_vcpu *source, unsigned long status)
+{
+	long ret;
+
+	ret = rmi_psci_complete(source->arch.rec.rec_phys, status);
+	if (ret)
+		return -ENXIO;
+
+	return 0;
+}
+
 static long realm_rtt_create(struct realm *realm,
 			     unsigned long addr,
 			     int level,
@@ -1145,6 +1157,30 @@ static int kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+static int kvm_rec_complete_psci(struct kvm_vcpu *vcpu)
+{
+	struct rec_run *run = vcpu->arch.rec.run;
+	unsigned long status = PSCI_RET_DENIED;
+	unsigned long ret = vcpu_get_reg(vcpu, 0);
+	int r;
+
+	switch (run->exit.gprs[0]) {
+	case PSCI_0_2_FN64_CPU_ON: {
+		if (ret != PSCI_RET_SUCCESS &&
+		    ret != PSCI_RET_ALREADY_ON)
+			status = PSCI_RET_DENIED;
+		else
+			status = PSCI_RET_SUCCESS;
+		break;
+	}
+	default:
+		return 1;
+	}
+
+	r = realm_psci_complete(vcpu, status);
+	return r ?: 1;
+}
+
 int kvm_rec_handle_request(struct kvm_vcpu *vcpu)
 {
 	struct realm_rec *rec = &vcpu->arch.rec;
@@ -1163,6 +1199,8 @@ int kvm_rec_handle_request(struct kvm_vcpu *vcpu)
 					vcpu_get_reg(vcpu, rt);
 		}
 		break;
+	case RMI_EXIT_PSCI:
+		return kvm_rec_complete_psci(vcpu);
 	case RMI_EXIT_RIPAS_CHANGE:
 		return kvm_complete_ripas_change(vcpu);
 	default:
-- 
2.43.0

[PATCH v16 33/45] KVM: arm64: WARN on injected undef exceptions

[Steven Price]

The RMM doesn't allow injection of a undefined exception into a realm
guest. Add a WARN to catch if this ever happens.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Switch to KVM_BUG() to mark the VM as bugged as well.
Changes since v6:
 * if (x) WARN(1, ...) makes no sense, just WARN(x, ...)!
---
 arch/arm64/kvm/inject_fault.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index 6492397b73d7..718419f40c1d 100644
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -327,6 +327,7 @@ void kvm_inject_size_fault(struct kvm_vcpu *vcpu)
  */
 void kvm_inject_undefined(struct kvm_vcpu *vcpu)
 {
+	KVM_BUG(vcpu_is_rec(vcpu), vcpu->kvm, "Unexpected undefined exception injection to REC");
 	if (vcpu_el1_is_32bit(vcpu))
 		inject_undef32(vcpu);
 	else
-- 
2.43.0

[PATCH v16 34/45] KVM: arm64: CCA: Allow userspace to inject aborts

[Steven Price]

From: Joey Gouly <joey.gouly@arm.com>

Extend KVM_SET_VCPU_EVENTS to support realms, where KVM cannot set the
system registers, and the RMM must perform it on next REC entry.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 Documentation/virt/kvm/api.rst |  2 ++
 arch/arm64/kvm/guest.c         | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 802601eaf560..1c9488df7e06 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -1317,6 +1317,8 @@ User space may need to inject several types of events to the guest.
 Set the pending SError exception state for this VCPU. It is not possible to
 'cancel' an Serror that has been made pending.
 
+User space cannot inject SErrors into Realms.
+
 If the guest performed an access to I/O memory which could not be handled by
 userspace, for example because of missing instruction syndrome decode
 information or because there is no device mapped at the accessed IPA, then
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3e970c4f6214..5469c9a97fad 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -827,6 +827,30 @@ int __kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
 	u64 esr = events->exception.serror_esr;
 	int ret = 0;
 
+	if (vcpu_is_rec(vcpu)) {
+		/* Cannot inject SError into a Realm. */
+		if (serror_pending)
+			return -EINVAL;
+
+		/*
+		 * If a data abort is pending, set the flag and let the RMM
+		 * inject an SEA when the REC is scheduled to be run.
+		 */
+		if (ext_dabt_pending) {
+			/*
+			 * Can only inject SEA into a Realm if the previous exit
+			 * was due to a data abort of an Unprotected IPA.
+			 */
+			if (!(vcpu->arch.rec.run->enter.flags & REC_ENTER_FLAG_EMULATED_MMIO))
+				return -EINVAL;
+
+			vcpu->arch.rec.run->enter.flags &= ~REC_ENTER_FLAG_EMULATED_MMIO;
+			vcpu->arch.rec.run->enter.flags |= REC_ENTER_FLAG_INJECT_SEA;
+		}
+
+		return 0;
+	}
+
 	/*
 	 * Immediately commit the pending SEA to the vCPU's architectural
 	 * state which is necessary since we do not return a pending SEA
-- 
2.43.0

[PATCH v16 35/45] KVM: arm64: CCA: Support RSI_HOST_CALL

[Steven Price]

From: Joey Gouly <joey.gouly@arm.com>

Realm VMs can talk to the hypervisor using the RSI_HOST_CALL SMC. The
RMM forwards this to the host and KVM handles them as regular
hypercalls.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v15:
 * Adapt to new exit handling.
Changes since v7:
 * Avoid turning a negative return from kvm_smccc_call_handler() into a
   error response to the guest. Instead propagate the error back to user
   space.
Changes since v4:
 * Setting GPRS is now done by kvm_rec_enter() rather than
   rec_exit_host_call() (see previous patch - arm64: RME: Handle realm
   enter/exit). This fixes a bug where the registers set by user space
   were being ignored.
---
 arch/arm64/kvm/rmi-exit.c | 1 +
 arch/arm64/kvm/rmi.c      | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c
index 1749cde2edff..7cde820bb77b 100644
--- a/arch/arm64/kvm/rmi-exit.c
+++ b/arch/arm64/kvm/rmi-exit.c
@@ -164,6 +164,7 @@ int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
 	case RMI_EXIT_SERROR:
 		return ARM_EXCEPTION_EL1_SERROR;
 	case RMI_EXIT_PSCI:
+	case RMI_EXIT_HOST_CALL:
 		rec_exit_hvc(vcpu);
 		kvm_make_request(KVM_REQ_RMI, vcpu);
 		return ARM_EXCEPTION_TRAP;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 3f31ad25680f..904df7c7245d 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -1203,6 +1203,10 @@ int kvm_rec_handle_request(struct kvm_vcpu *vcpu)
 		return kvm_rec_complete_psci(vcpu);
 	case RMI_EXIT_RIPAS_CHANGE:
 		return kvm_complete_ripas_change(vcpu);
+	case RMI_EXIT_HOST_CALL:
+		for (int i = 0; i < REC_RUN_GPRS; i++)
+			rec->run->enter.gprs[i] = vcpu_get_reg(vcpu, i);
+		break;
 	default:
 		KVM_BUG(1, vcpu->kvm, "Unhandled realm exit_reason");
 		return -ENXIO;
-- 
2.43.0

[PATCH v16 36/45] KVM: arm64: CCA: Allow checking SVE on VM instance

[Steven Price]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

Given we have different types of VMs supported, check the
support for SVE for the given instance of the VM to accurately
report the status.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
---
Changes since v10:
 * RME->RMI renaming.
 * Adapt to move CAP check to kvm_realm_ext_allowed().
---
 arch/arm64/include/asm/kvm_rmi.h | 2 ++
 arch/arm64/kvm/arm.c             | 2 ++
 arch/arm64/kvm/rmi.c             | 5 +++++
 3 files changed, 9 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 0fb685004d5c..13933f0e555d 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -98,6 +98,8 @@ struct realm_rec {
 void kvm_init_rmi(void);
 u32 kvm_rmm_ipa_limit(void);
 
+bool kvm_rmi_supports_sve(void);
+
 int kvm_init_realm(struct kvm *kvm);
 int kvm_activate_realm(struct kvm *kvm);
 void kvm_destroy_realm(struct kvm *kvm);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 96e536d2dda8..3242108be7c5 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -151,6 +151,8 @@ static bool kvm_realm_ext_allowed(long ext)
 	case KVM_CAP_ARM_RMI:
 	case KVM_CAP_SYNC_MMU:
 		return true;
+	case KVM_CAP_ARM_SVE:
+		return kvm_rmi_supports_sve();
 	}
 	return false;
 }
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 904df7c7245d..0d46768022df 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -26,6 +26,11 @@ static bool rmi_has_feature(int reg, unsigned long feature)
 	return !!u64_get_bits(rmi_feat_reg(reg), feature);
 }
 
+bool kvm_rmi_supports_sve(void)
+{
+	return rmi_has_feature(0, RMI_FEATURE_REGISTER_0_SVE);
+}
+
 u32 kvm_rmm_ipa_limit(void)
 {
 	return u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_S2SZ);
-- 
2.43.0

[PATCH v16 37/45] KVM: arm64: CCA: Prevent Device mappings for realms

[Steven Price]

Physical device assignment is not yet supported. RMM v2.0 does add the
relevant APIs, but device assignment is a big topic so will be handled
in a future patch series. For now prevent device mappings when the guest
is a realm.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes from v6:
 * Fix the check in user_mem_abort() to prevent all pages that are not
   guest_memfd() from being mapped into the protected half of the IPA.
Changes from v5:
 * Also prevent accesses in user_mem_abort()
---
 arch/arm64/kvm/mmu.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 79119cb136b0..dc27f3dfb337 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1261,6 +1261,10 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
 	if (is_protected_kvm_enabled())
 		return -EPERM;
 
+	/* We don't support mapping special pages into a Realm */
+	if (kvm_is_realm(kvm))
+		return -EPERM;
+
 	size += offset_in_page(guest_ipa);
 	guest_ipa &= PAGE_MASK;
 
-- 
2.43.0

[PATCH v16 38/45] KVM: arm64: CCA: Propagate breakpoint and watchpoint counts to userspace

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

The RMM describes the maximum number of BPs/WPs available to the guest
in the Feature Register 0. Propagate those numbers into ID_AA64DFR0_EL1,
which is visible to userspace. A VMM needs this information in order to
set up realm parameters.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
---
 arch/arm64/include/asm/kvm_rmi.h |  2 ++
 arch/arm64/kvm/rmi.c             | 19 +++++++++++++++++++
 arch/arm64/kvm/sys_regs.c        |  3 +++
 3 files changed, 24 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 13933f0e555d..7d27c17276bf 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -98,6 +98,8 @@ struct realm_rec {
 void kvm_init_rmi(void);
 u32 kvm_rmm_ipa_limit(void);
 
+u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
+
 bool kvm_rmi_supports_sve(void);
 
 int kvm_init_realm(struct kvm *kvm);
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 0d46768022df..de893308148e 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -36,6 +36,25 @@ u32 kvm_rmm_ipa_limit(void)
 	return u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_S2SZ);
 }
 
+u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
+{
+	u32 bps = u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_NUM_BPS);
+	u32 wps = u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_NUM_WPS);
+	u32 ctx_cmps;
+
+	/* Ensure CTX_CMPs is still valid */
+	ctx_cmps = FIELD_GET(ID_AA64DFR0_EL1_CTX_CMPs, val);
+	ctx_cmps = min(bps, ctx_cmps);
+
+	val &= ~(ID_AA64DFR0_EL1_BRPs_MASK | ID_AA64DFR0_EL1_WRPs_MASK |
+		 ID_AA64DFR0_EL1_CTX_CMPs);
+	val |= FIELD_PREP(ID_AA64DFR0_EL1_BRPs_MASK, bps) |
+	       FIELD_PREP(ID_AA64DFR0_EL1_WRPs_MASK, wps) |
+	       FIELD_PREP(ID_AA64DFR0_EL1_CTX_CMPs, ctx_cmps);
+
+	return val;
+}
+
 static int get_start_level(struct realm *realm)
 {
 	return 4 - stage2_pgtable_levels(realm->ia_bits);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 5d5c579d4579..e0fe9f2562bc 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2142,6 +2142,9 @@ static u64 sanitise_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
 	/* Hide BRBE from guests */
 	val &= ~ID_AA64DFR0_EL1_BRBE_MASK;
 
+	if (vcpu_is_rec(vcpu))
+		return kvm_realm_reset_id_aa64dfr0_el1(vcpu, val);
+
 	return val;
 }
 
-- 
2.43.0

[PATCH v16 39/45] KVM: arm64: CCA: Set breakpoint parameters through SET_ONE_REG

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

Allow userspace to configure the number of breakpoints and watchpoints
of a Realm VM through KVM_SET_ONE_REG ID_AA64DFR0_EL1.

The KVM sys_reg handler checks the user value against the maximum value
given by RMM (arm64_check_features() gets it from the
read_sanitised_id_aa64dfr0_el1() reset handler).

Userspace discovers that it can write these fields by issuing a
KVM_ARM_GET_REG_WRITABLE_MASKS ioctl.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm64/kvm/guest.c    |  7 +++++++
 arch/arm64/kvm/rmi.c      |  3 +++
 arch/arm64/kvm/sys_regs.c | 17 +++++++++++------
 3 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 5469c9a97fad..3ed563e85572 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -735,6 +735,8 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	return kvm_arm_sys_reg_get_reg(vcpu, reg);
 }
 
+#define KVM_REG_ARM_ID_AA64DFR0_EL1	ARM64_SYS_REG(3, 0, 0, 5, 0)
+
 /*
  * The RMI ABI only enables setting some GPRs and PC. The selection of GPRs
  * that are available depends on the Realm state and the reason for the last
@@ -749,6 +751,11 @@ static bool validate_realm_set_reg(struct kvm_vcpu *vcpu,
 		u64 off = core_reg_offset_from_id(reg->id);
 
 		return kvm_realm_validate_core_reg(off);
+	} else {
+		switch (reg->id) {
+		case KVM_REG_ARM_ID_AA64DFR0_EL1:
+			return true;
+		}
 	}
 
 	return false;
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index de893308148e..44ddee730863 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -505,6 +505,7 @@ static int realm_create_rd(struct kvm *kvm)
 	void *rd = NULL;
 	phys_addr_t rd_phys, params_phys, top_delegated;
 	size_t pgd_size = kvm_pgtable_stage2_pgd_size(kvm->arch.mmu.vtcr);
+	u64 dfr0 = kvm_read_vm_id_reg(kvm, SYS_ID_AA64DFR0_EL1);
 	long rmi_ret;
 	int r;
 
@@ -537,6 +538,8 @@ static int realm_create_rd(struct kvm *kvm)
 	params->rtt_level_start = get_start_level(realm);
 	params->rtt_num_start = pgd_size / PAGE_SIZE;
 	params->rtt_base = kvm->arch.mmu.pgd_phys;
+	params->num_bps = SYS_FIELD_GET(ID_AA64DFR0_EL1, BRPs, dfr0);
+	params->num_wps = SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, dfr0);
 	params->hash_algo = RMI_HASH_SHA_256;
 
 	if (kvm->arch.arm_pmu) {
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e0fe9f2562bc..e47be8f8d259 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2174,6 +2174,9 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
 {
 	u8 debugver = SYS_FIELD_GET(ID_AA64DFR0_EL1, DebugVer, val);
 	u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val);
+	u8 bps = SYS_FIELD_GET(ID_AA64DFR0_EL1, BRPs, val);
+	u8 wps = SYS_FIELD_GET(ID_AA64DFR0_EL1, WRPs, val);
+	u8 ctx_cmps = SYS_FIELD_GET(ID_AA64DFR0_EL1, CTX_CMPs, val);
 
 	/*
 	 * Prior to commit 3d0dba5764b9 ("KVM: arm64: PMU: Move the
@@ -2193,10 +2196,11 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
 		val &= ~ID_AA64DFR0_EL1_PMUVer_MASK;
 
 	/*
-	 * ID_AA64DFR0_EL1.DebugVer is one of those awkward fields with a
-	 * nonzero minimum safe value.
+	 * ID_AA64DFR0_EL1.DebugVer, BRPs and WRPs all have to be greater than
+	 * zero. CTX_CMPs is never greater than BRPs.
 	 */
-	if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP)
+	if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP || !bps || !wps ||
+	    ctx_cmps > bps)
 		return -EINVAL;
 
 	if (ignore_feat_doublelock(vcpu, val)) {
@@ -2429,10 +2433,11 @@ static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
 	mutex_lock(&vcpu->kvm->arch.config_lock);
 
 	/*
-	 * Once the VM has started the ID registers are immutable. Reject any
-	 * write that does not match the final register value.
+	 * Once the VM has started or the Realm descriptor is created, the ID
+	 * registers are immutable. Reject any write that does not match the
+	 * final register value.
 	 */
-	if (kvm_vm_has_ran_once(vcpu->kvm)) {
+	if (kvm_vm_has_ran_once(vcpu->kvm) || kvm_realm_is_created(vcpu->kvm)) {
 		if (val != read_id_reg(vcpu, rd))
 			ret = -EBUSY;
 		else
-- 
2.43.0

[PATCH v16 40/45] KVM: arm64: CCA: Propagate max SVE vector length from the RMM

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

RMM provides the maximum vector length it supports for a guest in its
feature register. Make it visible to the rest of KVM and to userspace
via KVM_REG_ARM64_SVE_VLS.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm64/include/asm/kvm_host.h |  2 +-
 arch/arm64/include/asm/kvm_rmi.h  |  1 +
 arch/arm64/kvm/guest.c            |  2 +-
 arch/arm64/kvm/reset.c            | 12 ++++++++++--
 arch/arm64/kvm/rmi.c              |  6 ++++++
 5 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 146c52f867c0..ee565b8e55a0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -79,9 +79,9 @@ enum kvm_mode kvm_get_mode(void);
 static inline enum kvm_mode kvm_get_mode(void) { return KVM_MODE_NONE; };
 #endif
 
-extern unsigned int __ro_after_init kvm_sve_max_vl;
 extern unsigned int __ro_after_init kvm_host_sve_max_vl;
 int __init kvm_arm_init_sve(void);
+unsigned int kvm_sve_get_max_vl(struct kvm *kvm);
 
 u32 __attribute_const__ kvm_target_cpu(void);
 void kvm_reset_vcpu(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 7d27c17276bf..2789879b6701 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -97,6 +97,7 @@ struct realm_rec {
 
 void kvm_init_rmi(void);
 u32 kvm_rmm_ipa_limit(void);
+unsigned int kvm_realm_sve_max_vl(void);
 
 u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val);
 
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3ed563e85572..f48fc0d5a249 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -375,7 +375,7 @@ static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 		if (vq_present(vqs, vq))
 			max_vq = vq;
 
-	if (max_vq > sve_vq_from_vl(kvm_sve_max_vl))
+	if (max_vq > sve_vq_from_vl(kvm_sve_get_max_vl(vcpu->kvm)))
 		return -EINVAL;
 
 	/*
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index c18cdca7d125..7b8681a602d4 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -46,7 +46,7 @@ unsigned int __ro_after_init kvm_host_sve_max_vl;
 #define VCPU_RESET_PSTATE_SVC	(PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \
 				 PSR_AA32_I_BIT | PSR_AA32_F_BIT)
 
-unsigned int __ro_after_init kvm_sve_max_vl;
+static unsigned int __ro_after_init kvm_sve_max_vl;
 
 int __init kvm_arm_init_sve(void)
 {
@@ -76,9 +76,17 @@ int __init kvm_arm_init_sve(void)
 	return 0;
 }
 
+unsigned int kvm_sve_get_max_vl(struct kvm *kvm)
+{
+	if (kvm_is_realm(kvm))
+		return kvm_realm_sve_max_vl();
+	else
+		return kvm_sve_max_vl;
+}
+
 static void kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.sve_max_vl = kvm_sve_max_vl;
+	vcpu->arch.sve_max_vl = kvm_sve_get_max_vl(vcpu->kvm);
 
 	/*
 	 * Userspace can still customize the vector lengths by writing
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 44ddee730863..cf043db05720 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -36,6 +36,12 @@ u32 kvm_rmm_ipa_limit(void)
 	return u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_S2SZ);
 }
 
+unsigned int kvm_realm_sve_max_vl(void)
+{
+	return sve_vl_from_vq(u64_get_bits(rmi_feat_reg(0),
+					   RMI_FEATURE_REGISTER_0_SVE_VL) + 1);
+}
+
 u64 kvm_realm_reset_id_aa64dfr0_el1(const struct kvm_vcpu *vcpu, u64 val)
 {
 	u32 bps = u64_get_bits(rmi_feat_reg(0), RMI_FEATURE_REGISTER_0_NUM_BPS);
-- 
2.43.0

[PATCH v16 41/45] KVM: arm64: CCA: Configure max SVE vector length for a Realm

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

Obtain the max vector length configured by userspace on the vCPUs, and
write it into the Realm parameters. By default the vCPU is configured
with the max vector length reported by RMM, and userspace can reduce it
with a write to KVM_REG_ARM64_SVE_VLS.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v6:
 * Rename max_vl/realm_max_vl to vl/last_vl - there is nothing "maximum"
   about them, we're just checking that all realms have the same vector
   length
---
 arch/arm64/kvm/guest.c |  3 ++-
 arch/arm64/kvm/rmi.c   | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index f48fc0d5a249..452cf5d3152e 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -361,7 +361,7 @@ static int set_sve_vls(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	if (!vcpu_has_sve(vcpu))
 		return -ENOENT;
 
-	if (kvm_arm_vcpu_sve_finalized(vcpu))
+	if (kvm_arm_vcpu_sve_finalized(vcpu) || kvm_realm_is_created(vcpu->kvm))
 		return -EPERM; /* too late! */
 
 	if (WARN_ON(vcpu->arch.sve_state))
@@ -754,6 +754,7 @@ static bool validate_realm_set_reg(struct kvm_vcpu *vcpu,
 	} else {
 		switch (reg->id) {
 		case KVM_REG_ARM_ID_AA64DFR0_EL1:
+		case KVM_REG_ARM64_SVE_VLS:
 			return true;
 		}
 	}
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index cf043db05720..0f66a0e970cd 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -504,6 +504,39 @@ static void realm_unmap_shared_range(struct kvm *kvm,
 			     start, end);
 }
 
+static int realm_init_sve_param(struct kvm *kvm, struct realm_params *params)
+{
+	unsigned long i;
+	struct kvm_vcpu *vcpu;
+	int vl, last_vl = -1;
+
+	if (!kvm_has_sve(kvm))
+		return 0;
+
+	/*
+	 * Get the preferred SVE configuration, set by userspace with the
+	 * KVM_ARM_VCPU_SVE feature and KVM_REG_ARM64_SVE_VLS pseudo-register.
+	 */
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		if (!kvm_arm_vcpu_sve_finalized(vcpu))
+			return -EINVAL;
+
+		vl = vcpu->arch.sve_max_vl;
+
+		/* We need all vCPUs to have the same SVE config */
+		if (last_vl >= 0 && last_vl != vl)
+			return -EINVAL;
+
+		last_vl = vl;
+	}
+
+	if (last_vl > 0) {
+		params->sve_vl = sve_vq_from_vl(last_vl) - 1;
+		params->flags0 |= RMI_REALM_PARAM_FLAG_SVE;
+	}
+	return 0;
+}
+
 static int realm_create_rd(struct kvm *kvm)
 {
 	struct realm *realm = &kvm->arch.realm;
@@ -556,6 +589,10 @@ static int realm_create_rd(struct kvm *kvm)
 	if (kvm_lpa2_is_enabled())
 		params->flags0 |= RMI_REALM_PARAM_FLAG_LPA2;
 
+	r = realm_init_sve_param(kvm, params);
+	if (r)
+		goto out_undelegate_tables;
+
 	params_phys = virt_to_phys(params);
 
 	rmi_ret = rmi_realm_create(rd_phys, params_phys, realm->sro);
-- 
2.43.0

[PATCH v16 42/45] KVM: arm64: CCA: Provide register list for unfinalized RECs

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

KVM_GET_REG_LIST should not be called before SVE is finalized. The ioctl
handler currently returns -EPERM in this case. But because it uses
kvm_arm_vcpu_is_finalized(), it now also rejects the call for
unfinalized REC even though finalizing the REC can only be done late,
after Realm descriptor creation.

Move the check to copy_sve_reg_indices(). One adverse side effect of
this change is that a KVM_GET_REG_LIST call that only probes for the
array size will now succeed even if SVE is not finalized, but that seems
harmless since the following KVM_GET_REG_LIST with the full array will
fail.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
 arch/arm64/kvm/arm.c   |  4 ----
 arch/arm64/kvm/guest.c | 10 +++++-----
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 3242108be7c5..fd4e13ff17cf 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1967,10 +1967,6 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 		if (unlikely(!kvm_vcpu_initialized(vcpu)))
 			break;
 
-		r = -EPERM;
-		if (!kvm_arm_vcpu_is_finalized(vcpu))
-			break;
-
 		r = -EFAULT;
 		if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
 			break;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 452cf5d3152e..128fec56993a 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -617,8 +617,8 @@ static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu)
 	if (!vcpu_has_sve(vcpu))
 		return 0;
 
-	/* Policed by KVM_GET_REG_LIST: */
-	WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu));
+	if (!kvm_arm_vcpu_sve_finalized(vcpu))
+		return 1; /* KVM_REG_ARM64_SVE_VLS */
 
 	return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */)
 		+ 1; /* KVM_REG_ARM64_SVE_VLS */
@@ -635,9 +635,6 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu,
 	if (!vcpu_has_sve(vcpu))
 		return 0;
 
-	/* Policed by KVM_GET_REG_LIST: */
-	WARN_ON(!kvm_arm_vcpu_sve_finalized(vcpu));
-
 	/*
 	 * Enumerate this first, so that userspace can save/restore in
 	 * the order reported by KVM_GET_REG_LIST:
@@ -647,6 +644,9 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu,
 		return -EFAULT;
 	++num_regs;
 
+	if (!kvm_arm_vcpu_sve_finalized(vcpu))
+		return num_regs;
+
 	for (i = 0; i < slices; i++) {
 		for (n = 0; n < SVE_NUM_ZREGS; n++) {
 			reg = KVM_REG_ARM64_SVE_ZREG(n, i);
-- 
2.43.0

[PATCH v16 43/45] KVM: arm64: CCA: Provide an accurate register list

[Steven Price]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

Userspace can set a few registers with KVM_SET_ONE_REG (9 GP registers
at runtime, and 3 system registers during initialization). Update the
register list returned by KVM_GET_REG_LIST.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes since v11:
 * Reworked due to upstream changes.
Changes since v8:
 * Minor type changes following review.
Changes since v7:
 * Reworked on upstream changes.
---
 arch/arm64/kvm/guest.c      |  6 ++++++
 arch/arm64/kvm/hypercalls.c |  4 ++--
 arch/arm64/kvm/sys_regs.c   | 27 +++++++++++++++++++++------
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 128fec56993a..5e495dd39e39 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -620,6 +620,9 @@ static unsigned long num_sve_regs(const struct kvm_vcpu *vcpu)
 	if (!kvm_arm_vcpu_sve_finalized(vcpu))
 		return 1; /* KVM_REG_ARM64_SVE_VLS */
 
+	if (kvm_is_realm(vcpu->kvm))
+		return 1; /* KVM_REG_ARM64_SVE_VLS */
+
 	return slices * (SVE_NUM_PREGS + SVE_NUM_ZREGS + 1 /* FFR */)
 		+ 1; /* KVM_REG_ARM64_SVE_VLS */
 }
@@ -647,6 +650,9 @@ static int copy_sve_reg_indices(const struct kvm_vcpu *vcpu,
 	if (!kvm_arm_vcpu_sve_finalized(vcpu))
 		return num_regs;
 
+	if (kvm_is_realm(vcpu->kvm))
+		return num_regs;
+
 	for (i = 0; i < slices; i++) {
 		for (n = 0; n < SVE_NUM_ZREGS; n++) {
 			reg = KVM_REG_ARM64_SVE_ZREG(n, i);
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index b11b8821c9fb..82278ccb19ae 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -414,14 +414,14 @@ void kvm_arm_teardown_hypercalls(struct kvm *kvm)
 
 int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
 {
-	return ARRAY_SIZE(kvm_arm_fw_reg_ids);
+	return kvm_is_realm(vcpu->kvm) ? 0 : ARRAY_SIZE(kvm_arm_fw_reg_ids);
 }
 
 int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 {
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(kvm_arm_fw_reg_ids); i++) {
+	for (i = 0; i < kvm_arm_get_fw_num_regs(vcpu); i++) {
 		if (put_user(kvm_arm_fw_reg_ids[i], uindices++))
 			return -EFAULT;
 	}
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e47be8f8d259..6d805160d70e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -5540,18 +5540,18 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
 				    sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
 }
 
-static unsigned int num_demux_regs(void)
+static inline unsigned int num_demux_regs(struct kvm_vcpu *vcpu)
 {
-	return CSSELR_MAX;
+	return kvm_is_realm(vcpu->kvm) ? 0 : CSSELR_MAX;
 }
 
-static int write_demux_regids(u64 __user *uindices)
+static int write_demux_regids(struct kvm_vcpu *vcpu, u64 __user *uindices)
 {
 	u64 val = KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
 	unsigned int i;
 
 	val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
-	for (i = 0; i < CSSELR_MAX; i++) {
+	for (i = 0; i < num_demux_regs(vcpu); i++) {
 		if (put_user(val | i, uindices))
 			return -EFAULT;
 		uindices++;
@@ -5595,11 +5595,26 @@ static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind)
 	return true;
 }
 
+static inline bool kvm_realm_sys_reg_hidden_user(const struct kvm_vcpu *vcpu,
+						 u64 reg)
+{
+	switch (reg) {
+	case SYS_ID_AA64DFR0_EL1:
+	case SYS_PMCR_EL0:
+		return false;
+	}
+	return true;
+}
+
 static int walk_one_sys_reg(const struct kvm_vcpu *vcpu,
 			    const struct sys_reg_desc *rd,
 			    u64 __user **uind,
 			    unsigned int *total)
 {
+	if (vcpu_is_rec(vcpu) &&
+	    kvm_realm_sys_reg_hidden_user(vcpu, reg_to_encoding(rd)))
+		return 0;
+
 	/*
 	 * Ignore registers we trap but don't save,
 	 * and for which no custom user accessor is provided.
@@ -5637,7 +5652,7 @@ static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
 
 unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu)
 {
-	return num_demux_regs()
+	return num_demux_regs(vcpu)
 		+ walk_sys_regs(vcpu, (u64 __user *)NULL);
 }
 
@@ -5650,7 +5665,7 @@ int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 		return err;
 	uindices += err;
 
-	return write_demux_regids(uindices);
+	return write_demux_regids(vcpu, uindices);
 }
 
 #define KVM_ARM_FEATURE_ID_RANGE_INDEX(r)			\
-- 
2.43.0

[PATCH v16 44/45] KVM: arm64: CCA: Require ICH_HCR_EL2.TDIR for realms

[Steven Price]

KVM advertises realm support when the RMM is available, and allows
userspace to create a VM with KVM_VM_TYPE_ARM_REALM on that basis.

On CPUs that lack ICH_HCR_EL2.TDIR, KVM uses ICH_HCR_EL2.TC for
normal guests so that ICC_DIR_EL1 is still trapped via the common GICv3
CPU interface trap. Realms cannot rely on the normal hyp-side trap
handling for that fallback, so advertising RMI support on such systems
lets userspace create a realm that cannot safely run.

Require the finalized ARM64_HAS_ICH_HCR_EL2_TDIR capability when
reporting KVM_CAP_ARM_RMI and when accepting KVM_VM_TYPE_ARM_REALM.
This leaves normal VM creation unchanged on systems that need the TC
workaround.

Signed-off-by: Steven Price <steven.price@arm.com>
---
New patch for v16
---
 arch/arm64/kvm/arm.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index fd4e13ff17cf..7edc572dd8ab 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -125,6 +125,12 @@ static bool vgic_present, kvm_arm_initialised;
 
 static DEFINE_PER_CPU(unsigned char, kvm_hyp_initialized);
 
+static bool kvm_arm_rmi_supported(void)
+{
+	return static_key_enabled(&kvm_rmi_is_available) &&
+	       cpus_have_final_cap(ARM64_HAS_ICH_HCR_EL2_TDIR);
+}
+
 bool is_kvm_arm_initialised(void)
 {
 	return kvm_arm_initialised;
@@ -256,7 +262,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 		return -EINVAL;
 
 	if (type & KVM_VM_TYPE_ARM_REALM) {
-		if (!static_branch_unlikely(&kvm_rmi_is_available))
+		if (!kvm_arm_rmi_supported())
 			return -EINVAL;
 		kvm_set_realm_state(kvm, REALM_STATE_NONE);
 		kvm->arch.is_realm = true;
@@ -537,7 +543,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 			r = kvm_supports_cacheable_pfnmap();
 		break;
 	case KVM_CAP_ARM_RMI:
-		r = static_key_enabled(&kvm_rmi_is_available);
+		r = kvm_arm_rmi_supported();
 		break;
 
 	default:
-- 
2.43.0

[PATCH v16 45/45] KVM: arm64: CCA: Enable realms to be created

[Steven Price]

All the pieces are now in place, so enable kvm_rmi_is_available when the
RMM is detected.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/rmi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 0f66a0e970cd..c242dfc2c7a6 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -1556,5 +1556,6 @@ void kvm_init_rmi(void)
 	if (rmm_check_features())
 		return;
 
-	/* Future patch will enable static branch kvm_rmi_is_available */
+	kvm_info("Realm guests supported\n");
+	static_branch_enable(&kvm_rmi_is_available);
 }
-- 
2.43.0

Re: [PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[Marc Zyngier]

On Mon, 03 Aug 2026 14:43:16 +0100,
Steven Price <steven.price@arm.com> wrote:
> 
> This series is based on the guest_memfd in-place conversion v9 tree[1],
> which is itself based on kvm-x86/next. It is also available as a git
> repository:

Well done. Series on top of another random series, based on a random
tree. Unusable. Have you realised there are reasons why we (KVM/arm64)
ask people to base their series on a *released* tag from Linus' tree?
This means that Sashiko cannot, once again, provide any feedback on
this series, as it fails to apply.

Just to avoid any ambiguity: Sashiko reviews, as annoying as they are,
are not optional. They are very much mandatory, and I wish I could
turn back the clocks to run it on my own code...

Running it on your own is not enough, because *I* want to see what the
tool finds. Not to mention that non-Gemini runs of sashiko are much
less interesting (unsurprisingly).

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[Steven Price]

On 03/08/2026 16:01, Marc Zyngier wrote:
> On Mon, 03 Aug 2026 14:43:16 +0100,
> Steven Price <steven.price@arm.com> wrote:
>>
>> This series is based on the guest_memfd in-place conversion v9 tree[1],
>> which is itself based on kvm-x86/next. It is also available as a git
>> repository:
> 
> Well done. Series on top of another random series, based on a random
> tree. Unusable. Have you realised there are reasons why we (KVM/arm64)
> ask people to base their series on a *released* tag from Linus' tree?
> This means that Sashiko cannot, once again, provide any feedback on
> this series, as it fails to apply.
> 
> Just to avoid any ambiguity: Sashiko reviews, as annoying as they are,
> are not optional. They are very much mandatory, and I wish I could
> turn back the clocks to run it on my own code...
> 
> Running it on your own is not enough, because *I* want to see what the
> tool finds. Not to mention that non-Gemini runs of sashiko are much
> less interesting (unsurprisingly).

Sorry, but I'm not sure what you expect me to do - clearly I want to
base my changes on top of the guest_memfd series which is being worked
on and not just ignore that work. So I've based my changes on top of the
tree that Ackerley published.

I'm certainly not trying to avoid the Sashiko reviews - it's a rather
unfortunate limitation of the public tool that it doesn't seem to be
able to deal with these dependencies. Or is there some magic that I can
do to fix this?

Thanks,
Steve

Re: [PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[Marc Zyngier]

On Mon, 03 Aug 2026 16:06:24 +0100,
Steven Price <steven.price@arm.com> wrote:
> 
> On 03/08/2026 16:01, Marc Zyngier wrote:
> > On Mon, 03 Aug 2026 14:43:16 +0100,
> > Steven Price <steven.price@arm.com> wrote:
> >>
> >> This series is based on the guest_memfd in-place conversion v9 tree[1],
> >> which is itself based on kvm-x86/next. It is also available as a git
> >> repository:
> > 
> > Well done. Series on top of another random series, based on a random
> > tree. Unusable. Have you realised there are reasons why we (KVM/arm64)
> > ask people to base their series on a *released* tag from Linus' tree?
> > This means that Sashiko cannot, once again, provide any feedback on
> > this series, as it fails to apply.
> > 
> > Just to avoid any ambiguity: Sashiko reviews, as annoying as they are,
> > are not optional. They are very much mandatory, and I wish I could
> > turn back the clocks to run it on my own code...
> > 
> > Running it on your own is not enough, because *I* want to see what the
> > tool finds. Not to mention that non-Gemini runs of sashiko are much
> > less interesting (unsurprisingly).
> 
> Sorry, but I'm not sure what you expect me to do - clearly I want to
> base my changes on top of the guest_memfd series which is being worked
> on and not just ignore that work. So I've based my changes on top of the
> tree that Ackerley published.

But that completely ignores the way the KVM/arm64 tree is managed. If
you base a series on a bunch of unmerged patches, how do you expect
people to do a sensible job at reviewing it? Now I need to ingest
another pile of random patches just to review this set?

Not happening, sorry.

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[Steven Price]

On 03/08/2026 16:20, Marc Zyngier wrote:
> On Mon, 03 Aug 2026 16:06:24 +0100,
> Steven Price <steven.price@arm.com> wrote:
>>
>> On 03/08/2026 16:01, Marc Zyngier wrote:
>>> On Mon, 03 Aug 2026 14:43:16 +0100,
>>> Steven Price <steven.price@arm.com> wrote:
>>>>
>>>> This series is based on the guest_memfd in-place conversion v9 tree[1],
>>>> which is itself based on kvm-x86/next. It is also available as a git
>>>> repository:
>>>
>>> Well done. Series on top of another random series, based on a random
>>> tree. Unusable. Have you realised there are reasons why we (KVM/arm64)
>>> ask people to base their series on a *released* tag from Linus' tree?
>>> This means that Sashiko cannot, once again, provide any feedback on
>>> this series, as it fails to apply.
>>>
>>> Just to avoid any ambiguity: Sashiko reviews, as annoying as they are,
>>> are not optional. They are very much mandatory, and I wish I could
>>> turn back the clocks to run it on my own code...
>>>
>>> Running it on your own is not enough, because *I* want to see what the
>>> tool finds. Not to mention that non-Gemini runs of sashiko are much
>>> less interesting (unsurprisingly).
>>
>> Sorry, but I'm not sure what you expect me to do - clearly I want to
>> base my changes on top of the guest_memfd series which is being worked
>> on and not just ignore that work. So I've based my changes on top of the
>> tree that Ackerley published.
> 
> But that completely ignores the way the KVM/arm64 tree is managed. If
> you base a series on a bunch of unmerged patches, how do you expect
> people to do a sensible job at reviewing it? Now I need to ingest
> another pile of random patches just to review this set?

It's based on the same 'base' as v15 was - it depends on the unmerged
guest_memfd changes. I've just updated to the latest revision from
Ackerley. You've been reviewing the changes, and I've attempted to
update the code based on that valuable feedback.

Clearly I'm not expecting this series to be merged yet - we're waiting
for the guest_memfd changes. If you have a suggestion on how I should
tackle this in the future then please let me know. I could bombard you
with an even bigger series with Ackerley's series on the front, but I
think you'd shout at me even more if I did that.

> Not happening, sorry.

Well I'm off on 'holiday' or more accurately to move house. The new
house's (brand new) hot water cylinder is bust and the plumber is
currently saying we can't even have cold water, never mind hot, so I'm
going to spend the next week worrying about things other than this series.

If you provide review comments then I'll look at them when I get back.

Thanks,
Steve

Re: [PATCH v16 17/45] KVM: arm64: CCA: Tear down RTTs

[Alper Gun]

On Mon, Aug 3, 2026 at 6:45 AM Steven Price <steven.price@arm.com> wrote:
> [...]
> +static void realm_unmap_stage2(struct kvm *kvm)
> +{
> +       struct realm *realm = &kvm->arch.realm;
> +
> +       lockdep_assert_held(&kvm->arch.config_lock);
> +
> +       if (realm->stage2_unmapped)
> +               return;
> +
> +       write_lock(&kvm->mmu_lock);
> +       kvm_stage2_unmap_range(&kvm->arch.mmu, 0,
> +                              BIT(realm->ia_bits - 1), true);
> +       write_unlock(&kvm->mmu_lock);
> +
> +       realm->stage2_unmapped = true;
> +}
> +
> +int kvm_realm_teardown_stage2(struct kvm *kvm)
> +{
> +       lockdep_assert_held(&kvm->arch.config_lock);
> +
> +       realm_unmap_stage2(kvm);
> +       return realm_destroy_rtts(kvm);
> +}

Hi Steven,

I noticed a warning in dmesg when destroying a realm:

  [  158.533495] Call trace:
  [  158.535927]  kvm_destroy_realm+0x208/0x218
  [  158.540356]  kvm_arch_destroy_vm+0xc8/0xd8
  [  158.544439]  kvm_put_kvm+0x324/0x4b0
  [  158.548002]  kvm_vm_stats_release+0x1c/0x38

I traced this and found the following:

At this point, calling realm_destroy_rtts() may fail destroying the RTTs
because RECs are still active and the Realm is not terminated, but the
walk finishes and still sets realm->rtts_destroyed = true.

Later, kvm_destroy_realm() calls rmi_realm_terminate() and then calls
realm_destroy_rtts(kvm) again. But because realm->rtts_destroyed is already
set to true, it exits early without tearing down the RTTs.

Consequently, rmi_realm_destroy() is invoked while the RTT tables still
exist in RMM, which fails and triggers WARN_ON(rmi_realm_destroy).

The fix I used was to remove realm_destroy_rtts() from
kvm_realm_teardown_stage2():
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -434,7 +434,7 @@ int kvm_realm_teardown_stage2(struct kvm *kvm)
  lockdep_assert_held(&kvm->arch.config_lock);

  realm_unmap_stage2(kvm);
- return realm_destroy_rtts(kvm);
+ return 0;
 }

I think we don't need RTT destruction here as it will be handled cleanly in
kvm_destroy_realm() later.

Thanks,
Alper

Re: [PATCH v16 21/45] KVM: arm64: CCA: Handle realm enter/exit

[Aneesh Kumar K.V]

Steven Price <steven.price@arm.com> writes:

> +	switch (rec->run->exit.exit_reason) {
> +	case RMI_EXIT_SYNC:
> +		/*
> +		 * HPFAR_EL2_NS is hijacked to indicate a valid HPFAR value,
> +		 * see __get_fault_info()
> +		 */
> +		vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar | HPFAR_EL2_NS;
> +		rec_exit_sync(vcpu);
> +		return ARM_EXCEPTION_TRAP;
> +	case RMI_EXIT_IRQ:
> +	case RMI_EXIT_FIQ:
> +		return ARM_EXCEPTION_IRQ;
> +	case RMI_EXIT_SERROR:
> +		return ARM_EXCEPTION_EL1_SERROR;
> +	case RMI_EXIT_PSCI:
> +		rec_exit_hvc(vcpu);
> +		kvm_make_request(KVM_REQ_RMI, vcpu);
> +		return ARM_EXCEPTION_TRAP;
> +	case RMI_EXIT_RIPAS_CHANGE:
> +		rec_exit_hvc(vcpu);
> +		return ARM_EXCEPTION_TRAP;
> +	}

Should we handle RMI_EXIT_RIPAS_CHANGE differently? Currently, the call path is:

kvm_rec_exit()
-> RMI_EXIT_RIPAS_CHANGE
-> handle_hvc()
-> kvm_rec_handle_hvc()
-> kvm_prepare_memory_fault_exit()

Could we instead treat RMI_EXIT_RIPAS_CHANGE as a special case and avoid
redirecting it through handle_hvc()? The completion part of the RIPAS
change could still be handled by kvm_rec_handle_request().


-bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret)
+static int rec_exit_ripas_change(struct kvm_vcpu *vcpu)
 {
-	struct realm_rec *rec;
+	struct realm_rec *rec = &vcpu->arch.rec;
 	struct realm *realm;
 	unsigned long base;
 	unsigned long ripas;
 	unsigned long top;
 
-	if (!vcpu_is_rec(vcpu))
-		return false;
-
-	rec = &vcpu->arch.rec;
-	if (rec->run->exit.exit_reason != RMI_EXIT_RIPAS_CHANGE)
-		return false;
-
 	realm = &vcpu->kvm->arch.realm;
 	base = rec->run->exit.ripas_base;
 	top = rec->run->exit.ripas_top;
@@ -89,8 +83,7 @@ bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret)
 			 base, top, ripas);
 		/* Set RMI_REJECT bit */
 		rec->run->enter.flags = REC_ENTER_FLAG_RIPAS_RESPONSE;
-		*ret = -EINVAL;
-		return true;
+		return -EINVAL;
 	}
 
 	/* Exit to VMM, the actual RIPAS change is done on next entry */
@@ -102,8 +95,7 @@ bool kvm_rec_handle_hvc(struct kvm_vcpu *vcpu, int *ret)
 	 * KVM_EXIT_MEMORY_FAULT requires a return code of -EFAULT, see the
 	 * API documentation
 	 */
-	*ret = -EFAULT;
-	return true;
+	return -EFAULT;
 }
 
 int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
@@ -169,8 +161,7 @@ int kvm_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret)
 		kvm_make_request(KVM_REQ_RMI, vcpu);
 		return ARM_EXCEPTION_TRAP;
 	case RMI_EXIT_RIPAS_CHANGE:
-		rec_exit_hvc(vcpu);
-		return ARM_EXCEPTION_TRAP;
+		return rec_exit_ripas_change(vcpu);
 	}
 
 	return rec_exit_fatal(vcpu, "Unsupported Realm exit reason",

-aneesh

Re: [PATCH v16 17/45] KVM: arm64: CCA: Tear down RTTs

[Suzuki K Poulose]

Hi there

On 03/08/2026 23:29, Alper Gun wrote:
> On Mon, Aug 3, 2026 at 6:45 AM Steven Price <steven.price@arm.com> wrote:
>> [...]
>> +static void realm_unmap_stage2(struct kvm *kvm)
>> +{
>> +       struct realm *realm = &kvm->arch.realm;
>> +
>> +       lockdep_assert_held(&kvm->arch.config_lock);
>> +
>> +       if (realm->stage2_unmapped)
>> +               return;
>> +
>> +       write_lock(&kvm->mmu_lock);
>> +       kvm_stage2_unmap_range(&kvm->arch.mmu, 0,
>> +                              BIT(realm->ia_bits - 1), true);
>> +       write_unlock(&kvm->mmu_lock);
>> +
>> +       realm->stage2_unmapped = true;
>> +}
>> +
>> +int kvm_realm_teardown_stage2(struct kvm *kvm)
>> +{
>> +       lockdep_assert_held(&kvm->arch.config_lock);
>> +
>> +       realm_unmap_stage2(kvm);
>> +       return realm_destroy_rtts(kvm);
>> +}
> 
> Hi Steven,
> 
> I noticed a warning in dmesg when destroying a realm:
> 
>    [  158.533495] Call trace:
>    [  158.535927]  kvm_destroy_realm+0x208/0x218
>    [  158.540356]  kvm_arch_destroy_vm+0xc8/0xd8
>    [  158.544439]  kvm_put_kvm+0x324/0x4b0
>    [  158.548002]  kvm_vm_stats_release+0x1c/0x38

Thanks for the report and the detailed analysis.

> 
> I traced this and found the following:
> 
> At this point, calling realm_destroy_rtts() may fail destroying the RTTs
> because RECs are still active and the Realm is not terminated, but the
> walk finishes and still sets realm->rtts_destroyed = true.
> 
> Later, kvm_destroy_realm() calls rmi_realm_terminate() and then calls
> realm_destroy_rtts(kvm) again. But because realm->rtts_destroyed is already
> set to true, it exits early without tearing down the RTTs.
> 
> Consequently, rmi_realm_destroy() is invoked while the RTT tables still
> exist in RMM, which fails and triggers WARN_ON(rmi_realm_destroy).
> 
> The fix I used was to remove realm_destroy_rtts() from
> kvm_realm_teardown_stage2():
> --- a/arch/arm64/kvm/rmi.c
> +++ b/arch/arm64/kvm/rmi.c
> @@ -434,7 +434,7 @@ int kvm_realm_teardown_stage2(struct kvm *kvm)
>    lockdep_assert_held(&kvm->arch.config_lock);
> 
>    realm_unmap_stage2(kvm);
> - return realm_destroy_rtts(kvm);
> + return 0;
>   }
> 
> I think we don't need RTT destruction here as it will be handled cleanly in
> kvm_destroy_realm() later.

That sounds sensible to me, I will take a look and fix it locally for 
the next version.


Thanks
Suzuki

> 
> Thanks,
> Alper

Re: [PATCH v16 21/45] KVM: arm64: CCA: Handle realm enter/exit

[Aneesh Kumar K.V]

Steven Price <steven.price@arm.com> writes:
> +
> +	switch (rec->run->exit.exit_reason) {
> +	case RMI_EXIT_SYNC:
> +		/*
> +		 * HPFAR_EL2_NS is hijacked to indicate a valid HPFAR value,
> +		 * see __get_fault_info()
> +		 */
> +		vcpu->arch.fault.hpfar_el2 = rec->run->exit.hpfar | HPFAR_EL2_NS;
> +		rec_exit_sync(vcpu);
> +		return ARM_EXCEPTION_TRAP;
> +	case RMI_EXIT_IRQ:
> +	case RMI_EXIT_FIQ:
> +		return ARM_EXCEPTION_IRQ;
> +	case RMI_EXIT_SERROR:
> +		return ARM_EXCEPTION_EL1_SERROR;
> +	case RMI_EXIT_PSCI:
> +		rec_exit_hvc(vcpu);
> +		kvm_make_request(KVM_REQ_RMI, vcpu);
>

I'm also wondering whether we can move the kvm_make_request() call until
after the PSCI/HOST_CALL handling is complete. I tried a quick hack, but
it did not look particularly clean, since we would end up adding
RMM-specific checks in handle_hvc():

ret = kvm_smccc_call_handler(vcpu);

if (vcpu_is_rec(vcpu) &&
    (vcpu->arch.rec.run->exit.exit_reason == RMI_EXIT_PSCI ||
     vcpu->arch.rec.run->exit.exit_reason == RMI_EXIT_HOST_CALL))
	kvm_make_request(KVM_REQ_RMI, vcpu);

That said, having rec_exit_hvc(vcpu) and kvm_make_request() back-to-back
is also somewhat confusing. Perhaps we could at least add a comment
explaining why the request must always be made here.


> +		return ARM_EXCEPTION_TRAP;
> +	case RMI_EXIT_RIPAS_CHANGE:
> +		rec_exit_hvc(vcpu);
> +		return ARM_EXCEPTION_TRAP;
> +	}
> +
> +	return rec_exit_fatal(vcpu, "Unsupported Realm exit reason",
> +			      rec->run->exit.exit_reason);
> +}

-aneesh

Re: [PATCH v16 00/45] arm64: Support for Arm CCA in KVM

[Fuad Tabba]

Hi Steven,

On Mon, 3 Aug 2026 at 14:44, Steven Price <steven.price@arm.com> wrote:
...
>  * Rewrite Realm entry and exit handling to fit into the generic KVM
>    run loop. Work which cannot be performed in the entry path is now
>    completed through KVM requests, and MMIO, PSCI, RIPAS changes and
>    host calls are adapted to the new flow.

Reading v16 with pKVM in mind: this rework helps, but the series still
adds a few kvm_is_realm()/vcpu_is_rec() checks to the core arm64 code,
and several sit next to, or inside the same condition as, the existing
pKVM checks (the nommu path in kvm_arch_vcpu_load(), the timer
offsets, the NISV abort injection). Both checks answer the same
question: is the guest's state owned by something other than KVM. It
might be worth a common predicate covering both.

Cheers,
/fuad



>
>  * Rewrite Realm timer support to use KVM's IRQ-ops infrastructure and
>    software resampling.
>
>  * Improve SRO cancellation and error handling. Ensure a cancelled
>    operation isn't treated as successful, wrapper return values can carry
>    negative Linux errors as well as RMI return values, and those errors
>    are propagated through the KVM users.
>
>  * Check that the RMM supports the host page size before configuring it,
>    and exclude firmware-reserved NOMAP memory when creating GPT entries.
>
>  * Expand the KVM_ARM_RMI_POPULATE documentation to make clear that Arm
>    CCA cannot preserve memory contents during an in-place
>    shared-to-private conversion.
>
>  * Allocate Realm parameters only while creating the Realm descriptor.
>
>  * Document the encoding of the arm64 VM types and require
>    ICH_HCR_EL2.TDIR before advertising or creating Realm VMs.
>
> This series is based on the guest_memfd in-place conversion v9 tree[1],
> which is itself based on kvm-x86/next. It is also available as a git
> repository:
>
> https://gitlab.arm.com/linux-arm/linux-cca cca-host/v16
>
> Work in progress changes for kvmtool are available from the git
> repository below:
>
> https://gitlab.arm.com/linux-arm/kvmtool-cca cca/v13
>
> The TF-RMM branch used for testing this series is available here:
>
> https://git.trustedfirmware.org/TF-RMM/tf-rmm.git topics/rmm-v2.0-poc_3
>
> There is a kvm-unit-test branch updated to support the attestation used
> in RMM v2.0 available here:
>
> https://gitlab.arm.com/linux-arm/kvm-unit-tests-cca cca/v4
>
> [0] https://developer.arm.com/documentation/den0137/2-0bet2/
> One bet2 change, which moves metadata out of the individual address
> range descriptors, has intentionally not been implemented because that
> part of the specification is expected to be reverted.
>
> [1] https://github.com/googleprodkernel/linux-cc/commits/guest_memfd-inplace-conversion-v9
>
> Jean-Philippe Brucker (6):
>   KVM: arm64: CCA: Propagate breakpoint and watchpoint counts to
>     userspace
>   KVM: arm64: CCA: Set breakpoint parameters through SET_ONE_REG
>   KVM: arm64: CCA: Propagate max SVE vector length from the RMM
>   KVM: arm64: CCA: Configure max SVE vector length for a Realm
>   KVM: arm64: CCA: Provide register list for unfinalized RECs
>   KVM: arm64: CCA: Provide an accurate register list
>
> Joey Gouly (2):
>   KVM: arm64: CCA: Allow userspace to inject aborts
>   KVM: arm64: CCA: Support RSI_HOST_CALL
>
> Steven Price (34):
>   firmware: arm_rmm: Add SMC definitions for calling the RMM
>   firmware: arm_rmm: Add wrappers for direct RMI calls
>   firmware: arm_rmm: Check for RMI support at init
>   firmware: arm_rmm: Configure the RMM with the host's page size
>   firmware: arm_rmm: Add support for SRO
>   firmware: arm_rmm: Ensure the RMM has GPT entries for memory
>   arm64: mm: Handle Granule Protection Faults (GPFs)
>   KVM: arm64: Avoid including linux/kvm_host.h in kvm_pgtable.h
>   KVM: arm64: CCA: Add wrappers for realm related RMIs
>   KVM: arm64: CCA: Check for RMI support at KVM init
>   KVM: arm64: CCA: Check for LPA2 support
>   KVM: arm64: CCA: Define the user ABI
>   KVM: arm64: CCA: Add basic infrastructure for creating a realm
>   KVM: arm64: CCA: Allow passing the machine type in KVM creation
>   KVM: arm64: CCA: Tear down RTTs
>   KVM: arm64: CCA: Allocate and free RECs to match vCPUs
>   KVM: arm64: CCA: Support the VGIC in realms
>   KVM: arm64: CCA: Support timers in realm RECs
>   KVM: arm64: CCA: Handle realm enter/exit
>   KVM: arm64: CCA: Handle RMI_EXIT_RIPAS_CHANGE
>   KVM: arm64: CCA: Handle realm MMIO emulation
>   KVM: arm64: Expose support for private memory
>   KVM: arm64: CCA: Create the realm descriptor
>   KVM: arm64: CCA: Activate realms on first vCPU run
>   KVM: arm64: CCA: Allow populating initial contents
>   KVM: arm64: CCA: Set RIPAS of initial memslots
>   KVM: arm64: CCA: Support runtime faulting of memory
>   KVM: arm64: CCA: Handle realm vCPU load
>   KVM: arm64: CCA: Validate register access for Realm VMs
>   KVM: arm64: CCA: Handle Realm PSCI requests
>   KVM: arm64: WARN on injected undef exceptions
>   KVM: arm64: CCA: Prevent Device mappings for realms
>   KVM: arm64: CCA: Require ICH_HCR_EL2.TDIR for realms
>   KVM: arm64: CCA: Enable realms to be created
>
> Suzuki K Poulose (3):
>   KVM: arm64: Include kvm_emulate.h in kvm/arm_psci.h
>   KVM: arm64: CCA: Don't expose unsupported capabilities for realm
>     guests
>   KVM: arm64: CCA: Allow checking SVE on VM instance
>
>  Documentation/virt/kvm/api.rst       |   70 +-
>  arch/arm64/Kconfig                   |    1 +
>  arch/arm64/include/asm/kvm_asm.h     |    2 +
>  arch/arm64/include/asm/kvm_emulate.h |   37 +
>  arch/arm64/include/asm/kvm_host.h    |   12 +-
>  arch/arm64/include/asm/kvm_pgtable.h |    6 +-
>  arch/arm64/include/asm/kvm_pkvm.h    |    2 +-
>  arch/arm64/include/asm/kvm_rmi.h     |  139 +++
>  arch/arm64/include/asm/rmi_cmds.h    |  465 ++++++++
>  arch/arm64/include/asm/virt.h        |    1 +
>  arch/arm64/kernel/cpufeature.c       |    1 +
>  arch/arm64/kvm/Kconfig               |    2 +
>  arch/arm64/kvm/Makefile              |    2 +-
>  arch/arm64/kvm/arch_timer.c          |   34 +-
>  arch/arm64/kvm/arm.c                 |  139 ++-
>  arch/arm64/kvm/guest.c               |   93 +-
>  arch/arm64/kvm/handle_exit.c         |   14 +
>  arch/arm64/kvm/hyp/pgtable.c         |    1 +
>  arch/arm64/kvm/hypercalls.c          |    4 +-
>  arch/arm64/kvm/inject_fault.c        |    5 +-
>  arch/arm64/kvm/mmio.c                |   16 +-
>  arch/arm64/kvm/mmu.c                 |  144 ++-
>  arch/arm64/kvm/reset.c               |   13 +-
>  arch/arm64/kvm/rmi-exit.c            |  178 +++
>  arch/arm64/kvm/rmi.c                 | 1561 ++++++++++++++++++++++++++
>  arch/arm64/kvm/sys_regs.c            |   47 +-
>  arch/arm64/kvm/vgic/vgic-init.c      |    2 +-
>  arch/arm64/mm/fault.c                |   28 +-
>  drivers/firmware/Kconfig             |    1 +
>  drivers/firmware/Makefile            |    1 +
>  drivers/firmware/arm_rmm/Kconfig     |   26 +
>  drivers/firmware/arm_rmm/Makefile    |    2 +
>  drivers/firmware/arm_rmm/rmi.c       |  776 +++++++++++++
>  include/kvm/arm_psci.h               |    2 +
>  include/linux/arm-rmi-cmds.h         |  201 ++++
>  include/linux/arm-smccc-rmi.h        |  493 ++++++++
>  include/uapi/linux/kvm.h             |   20 +-
>  37 files changed, 4446 insertions(+), 95 deletions(-)
>  create mode 100644 arch/arm64/include/asm/kvm_rmi.h
>  create mode 100644 arch/arm64/include/asm/rmi_cmds.h
>  create mode 100644 arch/arm64/kvm/rmi-exit.c
>  create mode 100644 arch/arm64/kvm/rmi.c
>  create mode 100644 drivers/firmware/arm_rmm/Kconfig
>  create mode 100644 drivers/firmware/arm_rmm/Makefile
>  create mode 100644 drivers/firmware/arm_rmm/rmi.c
>  create mode 100644 include/linux/arm-rmi-cmds.h
>  create mode 100644 include/linux/arm-smccc-rmi.h
>
> --
> 2.43.0
>

Re: [PATCH v16 11/45] KVM: arm64: CCA: Check for RMI support at KVM init

[Fuad Tabba]

Hi Steven,

On Mon, 3 Aug 2026 at 14:45, Steven Price <steven.price@arm.com> wrote:
...
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index bae2c4f92ef5..1a5e15040111 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -27,6 +27,7 @@
>  #include <asm/fpsimd.h>
>  #include <asm/kvm.h>
>  #include <asm/kvm_asm.h>
> +#include <asm/kvm_rmi.h>
>  #include <asm/vncr_mapping.h>
>
>  #define __KVM_HAVE_ARCH_INTC_INITIALIZED
> @@ -424,6 +425,9 @@ struct kvm_arch {
>         /* Nested virtualization info */
>         struct dentry *debugfs_nv_dentry;
>  #endif
> +
> +       bool is_realm;
> +       struct realm realm;
>  };

Marc suggested at v10 making the pKVM and CCA state here a union,
given the two are exclusive, and I believe you acked it [1]. Was there
an issue with it, or did it just get lost across the respins?

Cheers,
/fuad

[1] https://lore.kernel.org/all/86ms6azxt5.wl-maz@kernel.org/



>
>  struct kvm_vcpu_fault_info {
> diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
> new file mode 100644
> index 000000000000..57d24b244c95
> --- /dev/null
> +++ b/arch/arm64/include/asm/kvm_rmi.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2023-2026 ARM Ltd.
> + */
> +
> +#ifndef __ASM_KVM_RMI_H
> +#define __ASM_KVM_RMI_H
> +
> +/**
> + * struct realm - Additional per VM data for a Realm
> + */
> +struct realm {
> +};
> +
> +void kvm_init_rmi(void);
> +
> +#endif /* __ASM_KVM_RMI_H */
> diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
> index b546703c3ab9..92cec42952f4 100644
> --- a/arch/arm64/include/asm/virt.h
> +++ b/arch/arm64/include/asm/virt.h
> @@ -87,6 +87,7 @@ void __hyp_reset_vectors(void);
>  bool is_kvm_arm_initialised(void);
>
>  DECLARE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
> +DECLARE_STATIC_KEY_FALSE(kvm_rmi_is_available);
>
>  static inline bool is_pkvm_initialized(void)
>  {
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index 449154f9a485..189e8ad78b22 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -37,6 +37,7 @@ menuconfig KVM
>         select SCHED_INFO
>         select GUEST_PERF_EVENTS if PERF_EVENTS
>         select KVM_GUEST_MEMFD
> +       select ARM_RMM
>         help
>           Support hosting virtualized guest machines.
>
> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
> index 59612d2f277c..ed3cf30eb06e 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -16,7 +16,7 @@ CFLAGS_handle_exit.o += -Wno-override-init
>  kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
>          inject_fault.o va_layout.o handle_exit.o config.o \
>          guest.o debug.o reset.o sys_regs.o stacktrace.o \
> -        vgic-sys-reg-v3.o fpsimd.o pkvm.o \
> +        vgic-sys-reg-v3.o fpsimd.o pkvm.o rmi.o \
>          arch_timer.o trng.o vmid.o emulate-nested.o nested.o at.o \
>          vgic/vgic.o vgic/vgic-init.o \
>          vgic/vgic-irqfd.o vgic/vgic-v2.o \
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 50adfff75be8..b961c22fce3d 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -42,6 +42,7 @@
>  #include <asm/kvm_nested.h>
>  #include <asm/kvm_pkvm.h>
>  #include <asm/kvm_ptrauth.h>
> +#include <asm/kvm_rmi.h>
>  #include <asm/sections.h>
>  #include <asm/stacktrace/nvhe.h>
>
> @@ -111,6 +112,8 @@ long kvm_get_cap_for_kvm_ioctl(unsigned int ioctl, long *ext)
>         return -EINVAL;
>  }
>
> +DEFINE_STATIC_KEY_FALSE(kvm_rmi_is_available);
> +
>  DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
>
>  DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_base);
> @@ -3019,6 +3022,8 @@ static __init int kvm_arm_init(void)
>
>         in_hyp_mode = is_kernel_in_hyp_mode();
>
> +       kvm_init_rmi();
> +
>         if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
>             cpus_have_final_cap(ARM64_WORKAROUND_1508412))
>                 kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
> diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
> new file mode 100644
> index 000000000000..384991d69f78
> --- /dev/null
> +++ b/arch/arm64/kvm/rmi.c
> @@ -0,0 +1,24 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2023-2026 ARM Ltd.
> + */
> +
> +#include <linux/kvm_host.h>
> +
> +#include <asm/rmi_cmds.h>
> +#include <asm/virt.h>
> +
> +void kvm_init_rmi(void)
> +{
> +       /*
> +        * TODO: Support Realm guests in nVHE mode, this will require adding
> +        * EL2 stub(s) for REC entry and possibly other things.
> +        */
> +       if (!is_kernel_in_hyp_mode())
> +               return;
> +
> +       if (!is_rmi_available())
> +               return;
> +
> +       /* Future patch will enable static branch kvm_rmi_is_available */
> +}
> --
> 2.43.0
>

Re: [PATCH v16 11/45] KVM: arm64: CCA: Check for RMI support at KVM init

[Suzuki K Poulose]

On 04/08/2026 15:55, Fuad Tabba wrote:
> Hi Steven,
> 
> On Mon, 3 Aug 2026 at 14:45, Steven Price <steven.price@arm.com> wrote:
> ...
>> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
>> index bae2c4f92ef5..1a5e15040111 100644
>> --- a/arch/arm64/include/asm/kvm_host.h
>> +++ b/arch/arm64/include/asm/kvm_host.h
>> @@ -27,6 +27,7 @@
>>   #include <asm/fpsimd.h>
>>   #include <asm/kvm.h>
>>   #include <asm/kvm_asm.h>
>> +#include <asm/kvm_rmi.h>
>>   #include <asm/vncr_mapping.h>
>>
>>   #define __KVM_HAVE_ARCH_INTC_INITIALIZED
>> @@ -424,6 +425,9 @@ struct kvm_arch {
>>          /* Nested virtualization info */
>>          struct dentry *debugfs_nv_dentry;
>>   #endif
>> +
>> +       bool is_realm;
>> +       struct realm realm;
>>   };
> 
> Marc suggested at v10 making the pKVM and CCA state here a union,
> given the two are exclusive, and I believe you acked it [1]. Was there
> an issue with it, or did it just get lost across the respins?

Most likely lost in the respins. Will pick this up.

Thanks for spotting.

Cheers
Suzuki