* [PATCH v3 01/10] KVM: arm64: Block unsafe FF-A calls from the host
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 02/10] KVM: arm64: Probe FF-A version and host/hyp partition ID during init Will Deacon
` (9 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team, Andrew Walbran
When KVM is initialised in protected mode, we must take care to filter
certain FFA calls from the host kernel so that the integrity of guest
and hypervisor memory is maintained and is not made available to the
secure world.
As a first step, intercept and block all memory-related FF-A SMC calls
from the host to EL3 and don't advertise any FF-A features. This puts
the framework in place for handling them properly.
Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/include/nvhe/ffa.h | 16 ++++
arch/arm64/kvm/hyp/nvhe/Makefile | 2 +-
arch/arm64/kvm/hyp/nvhe/ffa.c | 119 ++++++++++++++++++++++++++
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 +
4 files changed, 139 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/kvm/hyp/include/nvhe/ffa.h
create mode 100644 arch/arm64/kvm/hyp/nvhe/ffa.c
diff --git a/arch/arm64/kvm/hyp/include/nvhe/ffa.h b/arch/arm64/kvm/hyp/include/nvhe/ffa.h
new file mode 100644
index 000000000000..fc09ec671e24
--- /dev/null
+++ b/arch/arm64/kvm/hyp/include/nvhe/ffa.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2022 - Google LLC
+ * Author: Andrew Walbran <qwandor@google.com>
+ */
+#ifndef __KVM_HYP_FFA_H
+#define __KVM_HYP_FFA_H
+
+#include <asm/kvm_host.h>
+
+#define FFA_MIN_FUNC_NUM 0x60
+#define FFA_MAX_FUNC_NUM 0x7F
+
+bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt);
+
+#endif /* __KVM_HYP_FFA_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index 530347cdebe3..9ddc025e4b86 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -22,7 +22,7 @@ lib-objs := $(addprefix ../../../lib/, $(lib-objs))
hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \
- cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o
+ cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o ffa.o
hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
hyp-obj-$(CONFIG_DEBUG_LIST) += list_debug.o
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
new file mode 100644
index 000000000000..302806928a64
--- /dev/null
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * FF-A v1.0 proxy to filter out invalid memory-sharing SMC calls issued by
+ * the host. FF-A is a slightly more palatable abbreviation of "Arm Firmware
+ * Framework for Arm A-profile", which is specified by Arm in document
+ * number DEN0077.
+ *
+ * Copyright (C) 2022 - Google LLC
+ * Author: Andrew Walbran <qwandor@google.com>
+ *
+ * This driver hooks into the SMC trapping logic for the host and intercepts
+ * all calls falling within the FF-A range. Each call is either:
+ *
+ * - Forwarded on unmodified to the SPMD at EL3
+ * - Rejected as "unsupported"
+ * - Accompanied by a host stage-2 page-table check/update and reissued
+ *
+ * Consequently, any attempts by the host to make guest memory pages
+ * accessible to the secure world using FF-A will be detected either here
+ * (in the case that the memory is already owned by the guest) or during
+ * donation to the guest (in the case that the memory was previously shared
+ * with the secure world).
+ *
+ * To allow the rolling-back of page-table updates and FF-A calls in the
+ * event of failure, operations involving the RXTX buffers are locked for
+ * the duration and are therefore serialised.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/arm_ffa.h>
+#include <nvhe/ffa.h>
+#include <nvhe/trap_handler.h>
+
+static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
+{
+ *res = (struct arm_smccc_res) {
+ .a0 = FFA_ERROR,
+ .a2 = ffa_errno,
+ };
+}
+
+static void ffa_set_retval(struct kvm_cpu_context *ctxt,
+ struct arm_smccc_res *res)
+{
+ cpu_reg(ctxt, 0) = res->a0;
+ cpu_reg(ctxt, 1) = res->a1;
+ cpu_reg(ctxt, 2) = res->a2;
+ cpu_reg(ctxt, 3) = res->a3;
+}
+
+static bool is_ffa_call(u64 func_id)
+{
+ return ARM_SMCCC_IS_FAST_CALL(func_id) &&
+ ARM_SMCCC_OWNER_NUM(func_id) == ARM_SMCCC_OWNER_STANDARD &&
+ ARM_SMCCC_FUNC_NUM(func_id) >= FFA_MIN_FUNC_NUM &&
+ ARM_SMCCC_FUNC_NUM(func_id) <= FFA_MAX_FUNC_NUM;
+}
+
+/*
+ * Is a given FFA function supported, either by forwarding on directly
+ * or by handling at EL2?
+ */
+static bool ffa_call_supported(u64 func_id)
+{
+ switch (func_id) {
+ /* Unsupported memory management calls */
+ case FFA_FN64_MEM_RETRIEVE_REQ:
+ case FFA_MEM_RETRIEVE_RESP:
+ case FFA_MEM_RELINQUISH:
+ case FFA_MEM_OP_PAUSE:
+ case FFA_MEM_OP_RESUME:
+ case FFA_MEM_FRAG_RX:
+ case FFA_FN64_MEM_DONATE:
+ /* Indirect message passing via RX/TX buffers */
+ case FFA_MSG_SEND:
+ case FFA_MSG_POLL:
+ case FFA_MSG_WAIT:
+ /* 32-bit variants of 64-bit calls */
+ case FFA_MSG_SEND_DIRECT_REQ:
+ case FFA_MSG_SEND_DIRECT_RESP:
+ case FFA_RXTX_MAP:
+ case FFA_MEM_DONATE:
+ case FFA_MEM_RETRIEVE_REQ:
+ /* Don't advertise any features just yet */
+ case FFA_FEATURES:
+ return false;
+ }
+
+ return true;
+}
+
+bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
+{
+ DECLARE_REG(u64, func_id, host_ctxt, 0);
+ struct arm_smccc_res res;
+
+ /*
+ * There's no way we can tell what a non-standard SMC call might
+ * be up to. Ideally, we would terminate these here and return
+ * an error to the host, but sadly devices make use of custom
+ * firmware calls for things like power management, debugging,
+ * RNG access and crash reporting.
+ *
+ * Given that the architecture requires us to trust EL3 anyway,
+ * we forward unrecognised calls on under the assumption that
+ * the firmware doesn't expose a mechanism to access arbitrary
+ * non-secure memory. Short of a per-device table of SMCs, this
+ * is the best we can do.
+ */
+ if (!is_ffa_call(func_id))
+ return false;
+
+ if (ffa_call_supported(func_id))
+ return false; /* Pass through */
+
+ ffa_to_smccc_error(&res, FFA_RET_NOT_SUPPORTED);
+ ffa_set_retval(host_ctxt, &res);
+ return true;
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 728e01d4536b..223611e43279 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -13,6 +13,7 @@
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
+#include <nvhe/ffa.h>
#include <nvhe/mem_protect.h>
#include <nvhe/mm.h>
#include <nvhe/pkvm.h>
@@ -373,6 +374,8 @@ static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
bool handled;
handled = kvm_host_psci_handler(host_ctxt);
+ if (!handled)
+ handled = kvm_host_ffa_handler(host_ctxt);
if (!handled)
default_host_smc_handler(host_ctxt);
--
2.40.1.698.g37aff9b760-goog
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 02/10] KVM: arm64: Probe FF-A version and host/hyp partition ID during init
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
2023-05-23 10:18 ` [PATCH v3 01/10] KVM: arm64: Block unsafe FF-A calls from the host Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 03/10] KVM: arm64: Allocate pages for hypervisor FF-A mailboxes Will Deacon
` (8 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team
Probe FF-A during pKVM initialisation so that we can detect any
inconsistencies in the version or partition ID early on.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/arm.c | 1 +
arch/arm64/kvm/hyp/include/nvhe/ffa.h | 1 +
arch/arm64/kvm/hyp/nvhe/ffa.c | 30 +++++++++++++++++++++++++++
arch/arm64/kvm/hyp/nvhe/setup.c | 5 +++++
5 files changed, 38 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 7e7e19ef6993..396e68cced9e 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -405,6 +405,7 @@ struct kvm_host_data {
struct kvm_host_psci_config {
/* PSCI version used by host. */
u32 version;
+ u32 smccc_version;
/* Function IDs used by host if version is v0.1. */
struct psci_0_1_function_ids function_ids_0_1;
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 14391826241c..41395693f3e2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1910,6 +1910,7 @@ static bool __init init_psci_relay(void)
}
kvm_host_psci_config.version = psci_ops.get_version();
+ kvm_host_psci_config.smccc_version = arm_smccc_get_version();
if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) {
kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids();
diff --git a/arch/arm64/kvm/hyp/include/nvhe/ffa.h b/arch/arm64/kvm/hyp/include/nvhe/ffa.h
index fc09ec671e24..5c9b92430ff3 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/ffa.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/ffa.h
@@ -11,6 +11,7 @@
#define FFA_MIN_FUNC_NUM 0x60
#define FFA_MAX_FUNC_NUM 0x7F
+int hyp_ffa_init(void);
bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt);
#endif /* __KVM_HYP_FFA_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 302806928a64..abdcaf98d9b0 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -31,6 +31,12 @@
#include <nvhe/ffa.h>
#include <nvhe/trap_handler.h>
+/*
+ * "ID value 0 must be returned at the Non-secure physical FF-A instance"
+ * We share this ID with the host.
+ */
+#define HOST_FFA_ID 0
+
static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
{
*res = (struct arm_smccc_res) {
@@ -117,3 +123,27 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
ffa_set_retval(host_ctxt, &res);
return true;
}
+
+int hyp_ffa_init(void)
+{
+ struct arm_smccc_res res;
+
+ if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
+ return 0;
+
+ arm_smccc_1_1_smc(FFA_VERSION, FFA_VERSION_1_0, 0, 0, 0, 0, 0, 0, &res);
+ if (res.a0 == FFA_RET_NOT_SUPPORTED)
+ return 0;
+
+ if (res.a0 != FFA_VERSION_1_0)
+ return -EOPNOTSUPP;
+
+ arm_smccc_1_1_smc(FFA_ID_GET, 0, 0, 0, 0, 0, 0, 0, &res);
+ if (res.a0 != FFA_SUCCESS)
+ return -EOPNOTSUPP;
+
+ if (res.a2 != HOST_FFA_ID)
+ return -EINVAL;
+
+ return 0;
+}
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index 110f04627785..c4ca174a0592 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -11,6 +11,7 @@
#include <asm/kvm_pkvm.h>
#include <nvhe/early_alloc.h>
+#include <nvhe/ffa.h>
#include <nvhe/fixed_config.h>
#include <nvhe/gfp.h>
#include <nvhe/memory.h>
@@ -314,6 +315,10 @@ void __noreturn __pkvm_init_finalise(void)
if (ret)
goto out;
+ ret = hyp_ffa_init();
+ if (ret)
+ goto out;
+
pkvm_hyp_vm_table_init(vm_table_base);
out:
/*
--
2.40.1.698.g37aff9b760-goog
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 03/10] KVM: arm64: Allocate pages for hypervisor FF-A mailboxes
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
2023-05-23 10:18 ` [PATCH v3 01/10] KVM: arm64: Block unsafe FF-A calls from the host Will Deacon
2023-05-23 10:18 ` [PATCH v3 02/10] KVM: arm64: Probe FF-A version and host/hyp partition ID during init Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 04/10] KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host Will Deacon
` (7 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team, Andrew Walbran
The FF-A proxy code needs to allocate its own buffer pair for
communication with EL3 and for forwarding calls from the host at EL1.
Reserve a couple of pages for this purpose and use them to initialise
the hypervisor's FF-A buffer structure.
Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/kvm_pkvm.h | 8 ++++++++
arch/arm64/kvm/hyp/include/nvhe/ffa.h | 2 +-
arch/arm64/kvm/hyp/nvhe/ffa.c | 24 +++++++++++++++++++++++-
arch/arm64/kvm/hyp/nvhe/setup.c | 8 +++++++-
arch/arm64/kvm/pkvm.c | 1 +
5 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h
index 01129b0d4c68..2b495ec59deb 100644
--- a/arch/arm64/include/asm/kvm_pkvm.h
+++ b/arch/arm64/include/asm/kvm_pkvm.h
@@ -106,4 +106,12 @@ static inline unsigned long host_s2_pgtable_pages(void)
return res;
}
+#define KVM_FFA_MBOX_NR_PAGES 1
+
+static inline unsigned long hyp_ffa_proxy_pages(void)
+{
+ /* A page each for the hypervisor's RX and TX mailboxes. */
+ return 2 * KVM_FFA_MBOX_NR_PAGES;
+}
+
#endif /* __ARM64_KVM_PKVM_H__ */
diff --git a/arch/arm64/kvm/hyp/include/nvhe/ffa.h b/arch/arm64/kvm/hyp/include/nvhe/ffa.h
index 5c9b92430ff3..1becb10ecd80 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/ffa.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/ffa.h
@@ -11,7 +11,7 @@
#define FFA_MIN_FUNC_NUM 0x60
#define FFA_MAX_FUNC_NUM 0x7F
-int hyp_ffa_init(void);
+int hyp_ffa_init(void *pages);
bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt);
#endif /* __KVM_HYP_FFA_H */
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index abdcaf98d9b0..c85e5d46a90d 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -28,8 +28,11 @@
#include <linux/arm-smccc.h>
#include <linux/arm_ffa.h>
+#include <asm/kvm_pkvm.h>
+
#include <nvhe/ffa.h>
#include <nvhe/trap_handler.h>
+#include <nvhe/spinlock.h>
/*
* "ID value 0 must be returned at the Non-secure physical FF-A instance"
@@ -37,6 +40,19 @@
*/
#define HOST_FFA_ID 0
+struct kvm_ffa_buffers {
+ hyp_spinlock_t lock;
+ void *tx;
+ void *rx;
+};
+
+/*
+ * Note that we don't currently lock these buffers explicitly, instead
+ * relying on the locking of the host FFA buffers as we only have one
+ * client.
+ */
+static struct kvm_ffa_buffers hyp_buffers;
+
static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
{
*res = (struct arm_smccc_res) {
@@ -124,7 +140,7 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
return true;
}
-int hyp_ffa_init(void)
+int hyp_ffa_init(void *pages)
{
struct arm_smccc_res res;
@@ -145,5 +161,11 @@ int hyp_ffa_init(void)
if (res.a2 != HOST_FFA_ID)
return -EINVAL;
+ hyp_buffers = (struct kvm_ffa_buffers) {
+ .lock = __HYP_SPIN_LOCK_UNLOCKED,
+ .tx = pages,
+ .rx = pages + (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE),
+ };
+
return 0;
}
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index c4ca174a0592..bb98630dfeaf 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -29,6 +29,7 @@ static void *vmemmap_base;
static void *vm_table_base;
static void *hyp_pgt_base;
static void *host_s2_pgt_base;
+static void *ffa_proxy_pages;
static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops;
static struct hyp_pool hpool;
@@ -58,6 +59,11 @@ static int divide_memory_pool(void *virt, unsigned long size)
if (!host_s2_pgt_base)
return -ENOMEM;
+ nr_pages = hyp_ffa_proxy_pages();
+ ffa_proxy_pages = hyp_early_alloc_contig(nr_pages);
+ if (!ffa_proxy_pages)
+ return -ENOMEM;
+
return 0;
}
@@ -315,7 +321,7 @@ void __noreturn __pkvm_init_finalise(void)
if (ret)
goto out;
- ret = hyp_ffa_init();
+ ret = hyp_ffa_init(ffa_proxy_pages);
if (ret)
goto out;
diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 6e9ece1ebbe7..994a494703c3 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -78,6 +78,7 @@ void __init kvm_hyp_reserve(void)
hyp_mem_pages += host_s2_pgtable_pages();
hyp_mem_pages += hyp_vm_table_pages();
hyp_mem_pages += hyp_vmemmap_pages(STRUCT_HYP_PAGE_SIZE);
+ hyp_mem_pages += hyp_ffa_proxy_pages();
/*
* Try to allocate a PMD-aligned region to reduce TLB pressure once
--
2.40.1.698.g37aff9b760-goog
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 04/10] KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (2 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 03/10] KVM: arm64: Allocate pages for hypervisor FF-A mailboxes Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 05/10] KVM: arm64: Add FF-A helpers to share/unshare memory with secure world Will Deacon
` (6 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team, Andrew Walbran
Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host by sharing
the host's mailbox memory with the hypervisor and establishing a
separate pair of mailboxes between the hypervisor and the SPMD at EL3.
Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 188 ++++++++++++++++++++++++++++++++++
include/linux/arm_ffa.h | 8 ++
2 files changed, 196 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index c85e5d46a90d..0c020cd9f722 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -31,6 +31,8 @@
#include <asm/kvm_pkvm.h>
#include <nvhe/ffa.h>
+#include <nvhe/mem_protect.h>
+#include <nvhe/memory.h>
#include <nvhe/trap_handler.h>
#include <nvhe/spinlock.h>
@@ -52,6 +54,7 @@ struct kvm_ffa_buffers {
* client.
*/
static struct kvm_ffa_buffers hyp_buffers;
+static struct kvm_ffa_buffers host_buffers;
static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
{
@@ -61,6 +64,15 @@ static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
};
}
+static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)
+{
+ if (ret == FFA_RET_SUCCESS) {
+ *res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS };
+ } else {
+ ffa_to_smccc_error(res, ret);
+ }
+}
+
static void ffa_set_retval(struct kvm_cpu_context *ctxt,
struct arm_smccc_res *res)
{
@@ -78,6 +90,144 @@ static bool is_ffa_call(u64 func_id)
ARM_SMCCC_FUNC_NUM(func_id) <= FFA_MAX_FUNC_NUM;
}
+static int ffa_map_hyp_buffers(u64 ffa_page_count)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_smc(FFA_FN64_RXTX_MAP,
+ hyp_virt_to_phys(hyp_buffers.tx),
+ hyp_virt_to_phys(hyp_buffers.rx),
+ ffa_page_count,
+ 0, 0, 0, 0,
+ &res);
+
+ return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
+}
+
+static int ffa_unmap_hyp_buffers(void)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_smc(FFA_RXTX_UNMAP,
+ HOST_FFA_ID,
+ 0, 0, 0, 0, 0, 0,
+ &res);
+
+ return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
+}
+
+static void do_ffa_rxtx_map(struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
+{
+ DECLARE_REG(phys_addr_t, tx, ctxt, 1);
+ DECLARE_REG(phys_addr_t, rx, ctxt, 2);
+ DECLARE_REG(u32, npages, ctxt, 3);
+ int ret = 0;
+ void *rx_virt, *tx_virt;
+
+ if (npages != (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) / FFA_PAGE_SIZE) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out;
+ }
+
+ if (!PAGE_ALIGNED(tx) || !PAGE_ALIGNED(rx)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out;
+ }
+
+ hyp_spin_lock(&host_buffers.lock);
+ if (host_buffers.tx) {
+ ret = FFA_RET_DENIED;
+ goto out_unlock;
+ }
+
+ /*
+ * Map our hypervisor buffers into the SPMD before mapping and
+ * pinning the host buffers in our own address space.
+ */
+ ret = ffa_map_hyp_buffers(npages);
+ if (ret)
+ goto out_unlock;
+
+ ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(tx));
+ if (ret) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto err_unmap;
+ }
+
+ ret = __pkvm_host_share_hyp(hyp_phys_to_pfn(rx));
+ if (ret) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto err_unshare_tx;
+ }
+
+ tx_virt = hyp_phys_to_virt(tx);
+ ret = hyp_pin_shared_mem(tx_virt, tx_virt + 1);
+ if (ret) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto err_unshare_rx;
+ }
+
+ rx_virt = hyp_phys_to_virt(rx);
+ ret = hyp_pin_shared_mem(rx_virt, rx_virt + 1);
+ if (ret) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto err_unpin_tx;
+ }
+
+ host_buffers.tx = tx_virt;
+ host_buffers.rx = rx_virt;
+
+out_unlock:
+ hyp_spin_unlock(&host_buffers.lock);
+out:
+ ffa_to_smccc_res(res, ret);
+ return;
+
+err_unpin_tx:
+ hyp_unpin_shared_mem(tx_virt, tx_virt + 1);
+err_unshare_rx:
+ __pkvm_host_unshare_hyp(hyp_phys_to_pfn(rx));
+err_unshare_tx:
+ __pkvm_host_unshare_hyp(hyp_phys_to_pfn(tx));
+err_unmap:
+ ffa_unmap_hyp_buffers();
+ goto out_unlock;
+}
+
+static void do_ffa_rxtx_unmap(struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
+{
+ DECLARE_REG(u32, id, ctxt, 1);
+ int ret = 0;
+
+ if (id != HOST_FFA_ID) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out;
+ }
+
+ hyp_spin_lock(&host_buffers.lock);
+ if (!host_buffers.tx) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ hyp_unpin_shared_mem(host_buffers.tx, host_buffers.tx + 1);
+ WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.tx)));
+ host_buffers.tx = NULL;
+
+ hyp_unpin_shared_mem(host_buffers.rx, host_buffers.rx + 1);
+ WARN_ON(__pkvm_host_unshare_hyp(hyp_virt_to_pfn(host_buffers.rx)));
+ host_buffers.rx = NULL;
+
+ ffa_unmap_hyp_buffers();
+
+out_unlock:
+ hyp_spin_unlock(&host_buffers.lock);
+out:
+ ffa_to_smccc_res(res, ret);
+}
+
/*
* Is a given FFA function supported, either by forwarding on directly
* or by handling at EL2?
@@ -132,10 +282,21 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
if (!is_ffa_call(func_id))
return false;
+ switch (func_id) {
+ /* Memory management */
+ case FFA_FN64_RXTX_MAP:
+ do_ffa_rxtx_map(&res, host_ctxt);
+ goto out_handled;
+ case FFA_RXTX_UNMAP:
+ do_ffa_rxtx_unmap(&res, host_ctxt);
+ goto out_handled;
+ }
+
if (ffa_call_supported(func_id))
return false; /* Pass through */
ffa_to_smccc_error(&res, FFA_RET_NOT_SUPPORTED);
+out_handled:
ffa_set_retval(host_ctxt, &res);
return true;
}
@@ -143,6 +304,7 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
int hyp_ffa_init(void *pages)
{
struct arm_smccc_res res;
+ size_t min_rxtx_sz;
if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
return 0;
@@ -161,11 +323,37 @@ int hyp_ffa_init(void *pages)
if (res.a2 != HOST_FFA_ID)
return -EINVAL;
+ arm_smccc_1_1_smc(FFA_FEATURES, FFA_FN64_RXTX_MAP,
+ 0, 0, 0, 0, 0, 0, &res);
+ if (res.a0 != FFA_SUCCESS)
+ return -EOPNOTSUPP;
+
+ switch (res.a2) {
+ case FFA_FEAT_RXTX_MIN_SZ_4K:
+ min_rxtx_sz = SZ_4K;
+ break;
+ case FFA_FEAT_RXTX_MIN_SZ_16K:
+ min_rxtx_sz = SZ_16K;
+ break;
+ case FFA_FEAT_RXTX_MIN_SZ_64K:
+ min_rxtx_sz = SZ_64K;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (min_rxtx_sz > PAGE_SIZE)
+ return -EOPNOTSUPP;
+
hyp_buffers = (struct kvm_ffa_buffers) {
.lock = __HYP_SPIN_LOCK_UNLOCKED,
.tx = pages,
.rx = pages + (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE),
};
+ host_buffers = (struct kvm_ffa_buffers) {
+ .lock = __HYP_SPIN_LOCK_UNLOCKED,
+ };
+
return 0;
}
diff --git a/include/linux/arm_ffa.h b/include/linux/arm_ffa.h
index c87aeecaa9b2..b9f81035eb41 100644
--- a/include/linux/arm_ffa.h
+++ b/include/linux/arm_ffa.h
@@ -94,6 +94,14 @@
*/
#define FFA_PAGE_SIZE SZ_4K
+/*
+ * Minimum buffer size/alignment encodings returned by an FFA_FEATURES
+ * query for FFA_RXTX_MAP.
+ */
+#define FFA_FEAT_RXTX_MIN_SZ_4K 0
+#define FFA_FEAT_RXTX_MIN_SZ_64K 1
+#define FFA_FEAT_RXTX_MIN_SZ_16K 2
+
/* FFA Bus/Device/Driver related */
struct ffa_device {
int vm_id;
--
2.40.1.698.g37aff9b760-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 05/10] KVM: arm64: Add FF-A helpers to share/unshare memory with secure world
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (3 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 04/10] KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 06/10] KVM: arm64: Handle FFA_MEM_SHARE calls from the host Will Deacon
` (5 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team, Andrew Walbran
Extend pKVM's memory protection code so that we can update the host's
stage-2 page-table to track pages shared with secure world by the host
using FF-A and prevent those pages from being mapped into a guest.
Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 3 +
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 68 +++++++++++++++++++
2 files changed, 71 insertions(+)
diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
index b7bdbe63deed..0972faccc2af 100644
--- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
+++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h
@@ -57,6 +57,7 @@ extern struct host_mmu host_mmu;
enum pkvm_component_id {
PKVM_ID_HOST,
PKVM_ID_HYP,
+ PKVM_ID_FFA,
};
extern unsigned long hyp_nr_cpus;
@@ -66,6 +67,8 @@ int __pkvm_host_share_hyp(u64 pfn);
int __pkvm_host_unshare_hyp(u64 pfn);
int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages);
int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages);
+int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages);
+int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages);
bool addr_is_memory(phys_addr_t phys);
int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot);
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 2e9ec4a2a4a3..e327e94d0e40 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -842,6 +842,13 @@ static int check_share(struct pkvm_mem_share *share)
case PKVM_ID_HYP:
ret = hyp_ack_share(completer_addr, tx, share->completer_prot);
break;
+ case PKVM_ID_FFA:
+ /*
+ * We only check the host; the secure side will check the other
+ * end when we forward the FFA call.
+ */
+ ret = 0;
+ break;
default:
ret = -EINVAL;
}
@@ -870,6 +877,13 @@ static int __do_share(struct pkvm_mem_share *share)
case PKVM_ID_HYP:
ret = hyp_complete_share(completer_addr, tx, share->completer_prot);
break;
+ case PKVM_ID_FFA:
+ /*
+ * We're not responsible for any secure page-tables, so there's
+ * nothing to do here.
+ */
+ ret = 0;
+ break;
default:
ret = -EINVAL;
}
@@ -918,6 +932,10 @@ static int check_unshare(struct pkvm_mem_share *share)
case PKVM_ID_HYP:
ret = hyp_ack_unshare(completer_addr, tx);
break;
+ case PKVM_ID_FFA:
+ /* See check_share() */
+ ret = 0;
+ break;
default:
ret = -EINVAL;
}
@@ -946,6 +964,10 @@ static int __do_unshare(struct pkvm_mem_share *share)
case PKVM_ID_HYP:
ret = hyp_complete_unshare(completer_addr, tx);
break;
+ case PKVM_ID_FFA:
+ /* See __do_share() */
+ ret = 0;
+ break;
default:
ret = -EINVAL;
}
@@ -1235,3 +1257,49 @@ void hyp_unpin_shared_mem(void *from, void *to)
hyp_unlock_component();
host_unlock_component();
}
+
+int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages)
+{
+ int ret;
+ struct pkvm_mem_share share = {
+ .tx = {
+ .nr_pages = nr_pages,
+ .initiator = {
+ .id = PKVM_ID_HOST,
+ .addr = hyp_pfn_to_phys(pfn),
+ },
+ .completer = {
+ .id = PKVM_ID_FFA,
+ },
+ },
+ };
+
+ host_lock_component();
+ ret = do_share(&share);
+ host_unlock_component();
+
+ return ret;
+}
+
+int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages)
+{
+ int ret;
+ struct pkvm_mem_share share = {
+ .tx = {
+ .nr_pages = nr_pages,
+ .initiator = {
+ .id = PKVM_ID_HOST,
+ .addr = hyp_pfn_to_phys(pfn),
+ },
+ .completer = {
+ .id = PKVM_ID_FFA,
+ },
+ },
+ };
+
+ host_lock_component();
+ ret = do_unshare(&share);
+ host_unlock_component();
+
+ return ret;
+}
--
2.40.1.698.g37aff9b760-goog
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 06/10] KVM: arm64: Handle FFA_MEM_SHARE calls from the host
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (4 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 05/10] KVM: arm64: Add FF-A helpers to share/unshare memory with secure world Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 07/10] KVM: arm64: Handle FFA_MEM_RECLAIM " Will Deacon
` (4 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team, Andrew Walbran
Intercept FFA_MEM_SHARE/FFA_FN64_MEM_SHARE calls from the host and
transition the host stage-2 page-table entries from the OWNED state to
the SHARED_OWNED state prior to forwarding the call onto EL3.
Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 155 ++++++++++++++++++++++++++++++++++
1 file changed, 155 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 0c020cd9f722..83c41c0c441d 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -116,6 +116,14 @@ static int ffa_unmap_hyp_buffers(void)
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
+static void ffa_mem_share(struct arm_smccc_res *res, u32 len, u32 fraglen)
+{
+ arm_smccc_1_1_smc(FFA_FN64_MEM_SHARE,
+ len, fraglen,
+ 0, 0, 0, 0, 0,
+ res);
+}
+
static void do_ffa_rxtx_map(struct arm_smccc_res *res,
struct kvm_cpu_context *ctxt)
{
@@ -228,6 +236,149 @@ static void do_ffa_rxtx_unmap(struct arm_smccc_res *res,
ffa_to_smccc_res(res, ret);
}
+static u32 __ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges,
+ u32 nranges)
+{
+ u32 i;
+
+ for (i = 0; i < nranges; ++i) {
+ struct ffa_mem_region_addr_range *range = &ranges[i];
+ u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE;
+ u64 pfn = hyp_phys_to_pfn(range->address);
+
+ if (!PAGE_ALIGNED(sz))
+ break;
+
+ if (__pkvm_host_share_ffa(pfn, sz / PAGE_SIZE))
+ break;
+ }
+
+ return i;
+}
+
+static u32 __ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
+ u32 nranges)
+{
+ u32 i;
+
+ for (i = 0; i < nranges; ++i) {
+ struct ffa_mem_region_addr_range *range = &ranges[i];
+ u64 sz = (u64)range->pg_cnt * FFA_PAGE_SIZE;
+ u64 pfn = hyp_phys_to_pfn(range->address);
+
+ if (!PAGE_ALIGNED(sz))
+ break;
+
+ if (__pkvm_host_unshare_ffa(pfn, sz / PAGE_SIZE))
+ break;
+ }
+
+ return i;
+}
+
+static int ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges,
+ u32 nranges)
+{
+ u32 nshared = __ffa_host_share_ranges(ranges, nranges);
+ int ret = 0;
+
+ if (nshared != nranges) {
+ WARN_ON(__ffa_host_unshare_ranges(ranges, nshared) != nshared);
+ ret = FFA_RET_DENIED;
+ }
+
+ return ret;
+}
+
+static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
+ u32 nranges)
+{
+ u32 nunshared = __ffa_host_unshare_ranges(ranges, nranges);
+ int ret = 0;
+
+ if (nunshared != nranges) {
+ WARN_ON(__ffa_host_share_ranges(ranges, nunshared) != nunshared);
+ ret = FFA_RET_DENIED;
+ }
+
+ return ret;
+}
+
+static void do_ffa_mem_share(struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
+{
+ DECLARE_REG(u32, len, ctxt, 1);
+ DECLARE_REG(u32, fraglen, ctxt, 2);
+ DECLARE_REG(u64, addr_mbz, ctxt, 3);
+ DECLARE_REG(u32, npages_mbz, ctxt, 4);
+ struct ffa_composite_mem_region *reg;
+ struct ffa_mem_region *buf;
+ int ret = 0;
+ u32 offset;
+
+ if (addr_mbz || npages_mbz || fraglen > len ||
+ fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out;
+ }
+
+ if (fraglen < len) {
+ ret = FFA_RET_ABORTED;
+ goto out;
+ }
+
+ if (fraglen < sizeof(struct ffa_mem_region) +
+ sizeof(struct ffa_mem_region_attributes)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out;
+ }
+
+ hyp_spin_lock(&host_buffers.lock);
+ if (!host_buffers.tx) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ buf = hyp_buffers.tx;
+ memcpy(buf, host_buffers.tx, fraglen);
+
+ offset = buf->ep_mem_access[0].composite_off;
+ if (!offset || buf->ep_count != 1 || buf->sender_id != HOST_FFA_ID) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ reg = (void *)buf + offset;
+ if (fraglen < offset + sizeof(struct ffa_composite_mem_region) +
+ reg->addr_range_cnt *
+ sizeof(struct ffa_mem_region_addr_range)) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ ret = ffa_host_share_ranges(reg->constituents, reg->addr_range_cnt);
+ if (ret)
+ goto out_unlock;
+
+ ffa_mem_share(res, len, fraglen);
+ if (res->a0 != FFA_SUCCESS) {
+ WARN_ON(ffa_host_unshare_ranges(reg->constituents,
+ reg->addr_range_cnt));
+ }
+
+out_unlock:
+ hyp_spin_unlock(&host_buffers.lock);
+out:
+ if (ret)
+ ffa_to_smccc_res(res, ret);
+ return;
+}
+
/*
* Is a given FFA function supported, either by forwarding on directly
* or by handling at EL2?
@@ -290,6 +441,10 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
case FFA_RXTX_UNMAP:
do_ffa_rxtx_unmap(&res, host_ctxt);
goto out_handled;
+ case FFA_MEM_SHARE:
+ case FFA_FN64_MEM_SHARE:
+ do_ffa_mem_share(&res, host_ctxt);
+ goto out_handled;
}
if (ffa_call_supported(func_id))
--
2.40.1.698.g37aff9b760-goog
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^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 07/10] KVM: arm64: Handle FFA_MEM_RECLAIM calls from the host
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (5 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 06/10] KVM: arm64: Handle FFA_MEM_SHARE calls from the host Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 08/10] KVM: arm64: Handle FFA_MEM_LEND " Will Deacon
` (3 subsequent siblings)
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team
Intecept FFA_MEM_RECLAIM calls from the host and transition the host
stage-2 page-table entries from the SHARED_OWNED state back to the OWNED
state once EL3 has confirmed that the secure mapping has been reclaimed.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 79 +++++++++++++++++++++++++++++++++++
1 file changed, 79 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 83c41c0c441d..550936f4b5da 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -124,6 +124,23 @@ static void ffa_mem_share(struct arm_smccc_res *res, u32 len, u32 fraglen)
res);
}
+static void ffa_mem_reclaim(struct arm_smccc_res *res, u32 handle_lo,
+ u32 handle_hi, u32 flags)
+{
+ arm_smccc_1_1_smc(FFA_MEM_RECLAIM,
+ handle_lo, handle_hi, flags,
+ 0, 0, 0, 0,
+ res);
+}
+
+static void ffa_retrieve_req(struct arm_smccc_res *res, u32 len)
+{
+ arm_smccc_1_1_smc(FFA_FN64_MEM_RETRIEVE_REQ,
+ len, len,
+ 0, 0, 0, 0, 0,
+ res);
+}
+
static void do_ffa_rxtx_map(struct arm_smccc_res *res,
struct kvm_cpu_context *ctxt)
{
@@ -379,6 +396,65 @@ static void do_ffa_mem_share(struct arm_smccc_res *res,
return;
}
+static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
+{
+ DECLARE_REG(u32, handle_lo, ctxt, 1);
+ DECLARE_REG(u32, handle_hi, ctxt, 2);
+ DECLARE_REG(u32, flags, ctxt, 3);
+ struct ffa_composite_mem_region *reg;
+ struct ffa_mem_region *buf;
+ int ret = 0;
+ u32 offset;
+ u64 handle;
+
+ handle = PACK_HANDLE(handle_lo, handle_hi);
+
+ hyp_spin_lock(&host_buffers.lock);
+
+ buf = hyp_buffers.tx;
+ *buf = (struct ffa_mem_region) {
+ .sender_id = HOST_FFA_ID,
+ .handle = handle,
+ };
+
+ ffa_retrieve_req(res, sizeof(*buf));
+ buf = hyp_buffers.rx;
+ if (res->a0 != FFA_MEM_RETRIEVE_RESP)
+ goto out_unlock;
+
+ /* Check for fragmentation */
+ if (res->a1 != res->a2) {
+ ret = FFA_RET_ABORTED;
+ goto out_unlock;
+ }
+
+ offset = buf->ep_mem_access[0].composite_off;
+ /*
+ * We can trust the SPMD to get this right, but let's at least
+ * check that we end up with something that doesn't look _completely_
+ * bogus.
+ */
+ if (WARN_ON(offset > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) {
+ ret = FFA_RET_ABORTED;
+ goto out_unlock;
+ }
+
+ reg = (void *)buf + offset;
+ ffa_mem_reclaim(res, handle_lo, handle_hi, flags);
+ if (res->a0 != FFA_SUCCESS)
+ goto out_unlock;
+
+ /* If the SPMD was happy, then we should be too. */
+ WARN_ON(ffa_host_unshare_ranges(reg->constituents,
+ reg->addr_range_cnt));
+out_unlock:
+ hyp_spin_unlock(&host_buffers.lock);
+
+ if (ret)
+ ffa_to_smccc_res(res, ret);
+}
+
/*
* Is a given FFA function supported, either by forwarding on directly
* or by handling at EL2?
@@ -445,6 +521,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
case FFA_FN64_MEM_SHARE:
do_ffa_mem_share(&res, host_ctxt);
goto out_handled;
+ case FFA_MEM_RECLAIM:
+ do_ffa_mem_reclaim(&res, host_ctxt);
+ goto out_handled;
}
if (ffa_call_supported(func_id))
--
2.40.1.698.g37aff9b760-goog
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 08/10] KVM: arm64: Handle FFA_MEM_LEND calls from the host
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (6 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 07/10] KVM: arm64: Handle FFA_MEM_RECLAIM " Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2025-07-12 13:55 ` [QUESTION] " daeroro
2023-05-23 10:18 ` [PATCH v3 09/10] KVM: arm64: Handle FFA_FEATURES call " Will Deacon
` (2 subsequent siblings)
10 siblings, 1 reply; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team
Handle FFA_MEM_LEND calls from the host by treating them identically to
FFA_MEM_SHARE calls for the purposes of the host stage-2 page-table, but
forwarding on the original request to EL3.
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 550936f4b5da..d90ab1c9ec72 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -116,10 +116,10 @@ static int ffa_unmap_hyp_buffers(void)
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
-static void ffa_mem_share(struct arm_smccc_res *res, u32 len, u32 fraglen)
+static void ffa_mem_xfer(struct arm_smccc_res *res, u64 func_id, u32 len,
+ u32 fraglen)
{
- arm_smccc_1_1_smc(FFA_FN64_MEM_SHARE,
- len, fraglen,
+ arm_smccc_1_1_smc(func_id, len, fraglen,
0, 0, 0, 0, 0,
res);
}
@@ -321,8 +321,9 @@ static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
return ret;
}
-static void do_ffa_mem_share(struct arm_smccc_res *res,
- struct kvm_cpu_context *ctxt)
+static __always_inline void do_ffa_mem_xfer(const u64 func_id,
+ struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
{
DECLARE_REG(u32, len, ctxt, 1);
DECLARE_REG(u32, fraglen, ctxt, 2);
@@ -333,6 +334,9 @@ static void do_ffa_mem_share(struct arm_smccc_res *res,
int ret = 0;
u32 offset;
+ BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
+ func_id != FFA_FN64_MEM_LEND);
+
if (addr_mbz || npages_mbz || fraglen > len ||
fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) {
ret = FFA_RET_INVALID_PARAMETERS;
@@ -382,7 +386,7 @@ static void do_ffa_mem_share(struct arm_smccc_res *res,
if (ret)
goto out_unlock;
- ffa_mem_share(res, len, fraglen);
+ ffa_mem_xfer(res, func_id, len, fraglen);
if (res->a0 != FFA_SUCCESS) {
WARN_ON(ffa_host_unshare_ranges(reg->constituents,
reg->addr_range_cnt));
@@ -519,11 +523,15 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
goto out_handled;
case FFA_MEM_SHARE:
case FFA_FN64_MEM_SHARE:
- do_ffa_mem_share(&res, host_ctxt);
+ do_ffa_mem_xfer(FFA_FN64_MEM_SHARE, &res, host_ctxt);
goto out_handled;
case FFA_MEM_RECLAIM:
do_ffa_mem_reclaim(&res, host_ctxt);
goto out_handled;
+ case FFA_MEM_LEND:
+ case FFA_FN64_MEM_LEND:
+ do_ffa_mem_xfer(FFA_FN64_MEM_LEND, &res, host_ctxt);
+ goto out_handled;
}
if (ffa_call_supported(func_id))
--
2.40.1.698.g37aff9b760-goog
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [QUESTION] KVM: arm64: Handle FFA_MEM_LEND calls from the host
2023-05-23 10:18 ` [PATCH v3 08/10] KVM: arm64: Handle FFA_MEM_LEND " Will Deacon
@ 2025-07-12 13:55 ` daeroro
0 siblings, 0 replies; 14+ messages in thread
From: daeroro @ 2025-07-12 13:55 UTC (permalink / raw)
To: will
Cc: alexandru.elisei, james.morse, kernel-team, kvmarm,
linux-arm-kernel, maz, oliver.upton, qperret, sebastianene,
sudeep.holla, suzuki.poulose, tabba
> Handle FFA_MEM_LEND calls from the host by treating them identically to
> FFA_MEM_SHARE calls for the purposes of the host stage-2 page-table, but
> forwarding on the original request to EL3.
Hello Will,
I have a question about your patch.
Does treating FFA_MEM_LEND as identical to FFA_MEM_SHARE imply that the host
can still access the memory even after it has been 'lent'?
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v3 09/10] KVM: arm64: Handle FFA_FEATURES call from the host
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (7 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 08/10] KVM: arm64: Handle FFA_MEM_LEND " Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-05-23 10:18 ` [PATCH v3 10/10] KVM: arm64: pkvm: Add support for fragmented FF-A descriptors Will Deacon
2023-06-07 5:35 ` [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Oliver Upton
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team
From: Fuad Tabba <tabba@google.com>
Filter out advertising unsupported features, and only advertise
features and properties that are supported by the hypervisor proxy.
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/ffa.c | 45 +++++++++++++++++++++++++++++++----
1 file changed, 41 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index d90ab1c9ec72..926314a9b9d7 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -64,15 +64,21 @@ static void ffa_to_smccc_error(struct arm_smccc_res *res, u64 ffa_errno)
};
}
-static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)
+static void ffa_to_smccc_res_prop(struct arm_smccc_res *res, int ret, u64 prop)
{
if (ret == FFA_RET_SUCCESS) {
- *res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS };
+ *res = (struct arm_smccc_res) { .a0 = FFA_SUCCESS,
+ .a2 = prop };
} else {
ffa_to_smccc_error(res, ret);
}
}
+static void ffa_to_smccc_res(struct arm_smccc_res *res, int ret)
+{
+ ffa_to_smccc_res_prop(res, ret, 0);
+}
+
static void ffa_set_retval(struct kvm_cpu_context *ctxt,
struct arm_smccc_res *res)
{
@@ -484,14 +490,41 @@ static bool ffa_call_supported(u64 func_id)
case FFA_RXTX_MAP:
case FFA_MEM_DONATE:
case FFA_MEM_RETRIEVE_REQ:
- /* Don't advertise any features just yet */
- case FFA_FEATURES:
return false;
}
return true;
}
+static bool do_ffa_features(struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
+{
+ DECLARE_REG(u32, id, ctxt, 1);
+ u64 prop = 0;
+ int ret = 0;
+
+ if (!ffa_call_supported(id)) {
+ ret = FFA_RET_NOT_SUPPORTED;
+ goto out_handled;
+ }
+
+ switch (id) {
+ case FFA_MEM_SHARE:
+ case FFA_FN64_MEM_SHARE:
+ case FFA_MEM_LEND:
+ case FFA_FN64_MEM_LEND:
+ ret = FFA_RET_SUCCESS;
+ prop = 0; /* No support for dynamic buffers */
+ goto out_handled;
+ default:
+ return false;
+ }
+
+out_handled:
+ ffa_to_smccc_res_prop(res, ret, prop);
+ return true;
+}
+
bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
{
DECLARE_REG(u64, func_id, host_ctxt, 0);
@@ -514,6 +547,10 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
return false;
switch (func_id) {
+ case FFA_FEATURES:
+ if (!do_ffa_features(&res, host_ctxt))
+ return false;
+ goto out_handled;
/* Memory management */
case FFA_FN64_RXTX_MAP:
do_ffa_rxtx_map(&res, host_ctxt);
--
2.40.1.698.g37aff9b760-goog
_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 10/10] KVM: arm64: pkvm: Add support for fragmented FF-A descriptors
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (8 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 09/10] KVM: arm64: Handle FFA_FEATURES call " Will Deacon
@ 2023-05-23 10:18 ` Will Deacon
2023-06-07 5:35 ` [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Oliver Upton
10 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-05-23 10:18 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Will Deacon, Quentin Perret, Marc Zyngier, Oliver Upton,
James Morse, Alexandru Elisei, Suzuki K Poulose, Sudeep Holla,
Sebastian Ene, Fuad Tabba, kvmarm, kernel-team, Andrew Walbran
From: Quentin Perret <qperret@google.com>
FF-A memory descriptors may need to be sent in fragments when they don't
fit in the mailboxes. Doing so involves using the FRAG_TX and FRAG_RX
primitives defined in the FF-A protocol.
Add support in the pKVM FF-A relayer for fragmented descriptors by
monitoring outgoing FRAG_TX transactions and by buffering large
descriptors on the reclaim path.
Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/kvm_pkvm.h | 17 ++-
arch/arm64/kvm/hyp/nvhe/ffa.c | 170 ++++++++++++++++++++++++++----
2 files changed, 162 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h
index 2b495ec59deb..e46250a02017 100644
--- a/arch/arm64/include/asm/kvm_pkvm.h
+++ b/arch/arm64/include/asm/kvm_pkvm.h
@@ -6,7 +6,9 @@
#ifndef __ARM64_KVM_PKVM_H__
#define __ARM64_KVM_PKVM_H__
+#include <linux/arm_ffa.h>
#include <linux/memblock.h>
+#include <linux/scatterlist.h>
#include <asm/kvm_pgtable.h>
/* Maximum number of VMs that can co-exist under pKVM. */
@@ -110,8 +112,19 @@ static inline unsigned long host_s2_pgtable_pages(void)
static inline unsigned long hyp_ffa_proxy_pages(void)
{
- /* A page each for the hypervisor's RX and TX mailboxes. */
- return 2 * KVM_FFA_MBOX_NR_PAGES;
+ size_t desc_max;
+
+ /*
+ * The hypervisor FFA proxy needs enough memory to buffer a fragmented
+ * descriptor returned from EL3 in response to a RETRIEVE_REQ call.
+ */
+ desc_max = sizeof(struct ffa_mem_region) +
+ sizeof(struct ffa_mem_region_attributes) +
+ sizeof(struct ffa_composite_mem_region) +
+ SG_MAX_SEGMENTS * sizeof(struct ffa_mem_region_addr_range);
+
+ /* Plus a page each for the hypervisor's RX and TX mailboxes. */
+ return (2 * KVM_FFA_MBOX_NR_PAGES) + DIV_ROUND_UP(desc_max, PAGE_SIZE);
}
#endif /* __ARM64_KVM_PKVM_H__ */
diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 926314a9b9d7..58dcd92bf346 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -42,6 +42,18 @@
*/
#define HOST_FFA_ID 0
+/*
+ * A buffer to hold the maximum descriptor size we can see from the host,
+ * which is required when the SPMD returns a fragmented FFA_MEM_RETRIEVE_RESP
+ * when resolving the handle on the reclaim path.
+ */
+struct kvm_ffa_descriptor_buffer {
+ void *buf;
+ size_t len;
+};
+
+static struct kvm_ffa_descriptor_buffer ffa_desc_buf;
+
struct kvm_ffa_buffers {
hyp_spinlock_t lock;
void *tx;
@@ -122,6 +134,24 @@ static int ffa_unmap_hyp_buffers(void)
return res.a0 == FFA_SUCCESS ? FFA_RET_SUCCESS : res.a2;
}
+static void ffa_mem_frag_tx(struct arm_smccc_res *res, u32 handle_lo,
+ u32 handle_hi, u32 fraglen, u32 endpoint_id)
+{
+ arm_smccc_1_1_smc(FFA_MEM_FRAG_TX,
+ handle_lo, handle_hi, fraglen, endpoint_id,
+ 0, 0, 0,
+ res);
+}
+
+static void ffa_mem_frag_rx(struct arm_smccc_res *res, u32 handle_lo,
+ u32 handle_hi, u32 fragoff)
+{
+ arm_smccc_1_1_smc(FFA_MEM_FRAG_RX,
+ handle_lo, handle_hi, fragoff, HOST_FFA_ID,
+ 0, 0, 0,
+ res);
+}
+
static void ffa_mem_xfer(struct arm_smccc_res *res, u64 func_id, u32 len,
u32 fraglen)
{
@@ -327,6 +357,64 @@ static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
return ret;
}
+static void do_ffa_mem_frag_tx(struct arm_smccc_res *res,
+ struct kvm_cpu_context *ctxt)
+{
+ DECLARE_REG(u32, handle_lo, ctxt, 1);
+ DECLARE_REG(u32, handle_hi, ctxt, 2);
+ DECLARE_REG(u32, fraglen, ctxt, 3);
+ DECLARE_REG(u32, endpoint_id, ctxt, 4);
+ struct ffa_mem_region_addr_range *buf;
+ int ret = FFA_RET_INVALID_PARAMETERS;
+ u32 nr_ranges;
+
+ if (fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)
+ goto out;
+
+ if (fraglen % sizeof(*buf))
+ goto out;
+
+ hyp_spin_lock(&host_buffers.lock);
+ if (!host_buffers.tx)
+ goto out_unlock;
+
+ buf = hyp_buffers.tx;
+ memcpy(buf, host_buffers.tx, fraglen);
+ nr_ranges = fraglen / sizeof(*buf);
+
+ ret = ffa_host_share_ranges(buf, nr_ranges);
+ if (ret) {
+ /*
+ * We're effectively aborting the transaction, so we need
+ * to restore the global state back to what it was prior to
+ * transmission of the first fragment.
+ */
+ ffa_mem_reclaim(res, handle_lo, handle_hi, 0);
+ WARN_ON(res->a0 != FFA_SUCCESS);
+ goto out_unlock;
+ }
+
+ ffa_mem_frag_tx(res, handle_lo, handle_hi, fraglen, endpoint_id);
+ if (res->a0 != FFA_SUCCESS && res->a0 != FFA_MEM_FRAG_RX)
+ WARN_ON(ffa_host_unshare_ranges(buf, nr_ranges));
+
+out_unlock:
+ hyp_spin_unlock(&host_buffers.lock);
+out:
+ if (ret)
+ ffa_to_smccc_res(res, ret);
+
+ /*
+ * If for any reason this did not succeed, we're in trouble as we have
+ * now lost the content of the previous fragments and we can't rollback
+ * the host stage-2 changes. The pages previously marked as shared will
+ * remain stuck in that state forever, hence preventing the host from
+ * sharing/donating them again and may possibly lead to subsequent
+ * failures, but this will not compromise confidentiality.
+ */
+ return;
+}
+
static __always_inline void do_ffa_mem_xfer(const u64 func_id,
struct arm_smccc_res *res,
struct kvm_cpu_context *ctxt)
@@ -337,8 +425,8 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id,
DECLARE_REG(u32, npages_mbz, ctxt, 4);
struct ffa_composite_mem_region *reg;
struct ffa_mem_region *buf;
+ u32 offset, nr_ranges;
int ret = 0;
- u32 offset;
BUILD_BUG_ON(func_id != FFA_FN64_MEM_SHARE &&
func_id != FFA_FN64_MEM_LEND);
@@ -349,11 +437,6 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id,
goto out;
}
- if (fraglen < len) {
- ret = FFA_RET_ABORTED;
- goto out;
- }
-
if (fraglen < sizeof(struct ffa_mem_region) +
sizeof(struct ffa_mem_region_attributes)) {
ret = FFA_RET_INVALID_PARAMETERS;
@@ -381,21 +464,26 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id,
}
reg = (void *)buf + offset;
- if (fraglen < offset + sizeof(struct ffa_composite_mem_region) +
- reg->addr_range_cnt *
- sizeof(struct ffa_mem_region_addr_range)) {
+ nr_ranges = ((void *)buf + fraglen) - (void *)reg->constituents;
+ if (nr_ranges % sizeof(reg->constituents[0])) {
ret = FFA_RET_INVALID_PARAMETERS;
goto out_unlock;
}
- ret = ffa_host_share_ranges(reg->constituents, reg->addr_range_cnt);
+ nr_ranges /= sizeof(reg->constituents[0]);
+ ret = ffa_host_share_ranges(reg->constituents, nr_ranges);
if (ret)
goto out_unlock;
ffa_mem_xfer(res, func_id, len, fraglen);
- if (res->a0 != FFA_SUCCESS) {
- WARN_ON(ffa_host_unshare_ranges(reg->constituents,
- reg->addr_range_cnt));
+ if (fraglen != len) {
+ if (res->a0 != FFA_MEM_FRAG_RX)
+ goto err_unshare;
+
+ if (res->a3 != fraglen)
+ goto err_unshare;
+ } else if (res->a0 != FFA_SUCCESS) {
+ goto err_unshare;
}
out_unlock:
@@ -404,6 +492,10 @@ static __always_inline void do_ffa_mem_xfer(const u64 func_id,
if (ret)
ffa_to_smccc_res(res, ret);
return;
+
+err_unshare:
+ WARN_ON(ffa_host_unshare_ranges(reg->constituents, nr_ranges));
+ goto out_unlock;
}
static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
@@ -413,9 +505,9 @@ static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
DECLARE_REG(u32, handle_hi, ctxt, 2);
DECLARE_REG(u32, flags, ctxt, 3);
struct ffa_composite_mem_region *reg;
+ u32 offset, len, fraglen, fragoff;
struct ffa_mem_region *buf;
int ret = 0;
- u32 offset;
u64 handle;
handle = PACK_HANDLE(handle_lo, handle_hi);
@@ -433,11 +525,8 @@ static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
if (res->a0 != FFA_MEM_RETRIEVE_RESP)
goto out_unlock;
- /* Check for fragmentation */
- if (res->a1 != res->a2) {
- ret = FFA_RET_ABORTED;
- goto out_unlock;
- }
+ len = res->a1;
+ fraglen = res->a2;
offset = buf->ep_mem_access[0].composite_off;
/*
@@ -445,16 +534,36 @@ static void do_ffa_mem_reclaim(struct arm_smccc_res *res,
* check that we end up with something that doesn't look _completely_
* bogus.
*/
- if (WARN_ON(offset > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) {
+ if (WARN_ON(offset > len ||
+ fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) {
ret = FFA_RET_ABORTED;
goto out_unlock;
}
- reg = (void *)buf + offset;
+ if (len > ffa_desc_buf.len) {
+ ret = FFA_RET_NO_MEMORY;
+ goto out_unlock;
+ }
+
+ buf = ffa_desc_buf.buf;
+ memcpy(buf, hyp_buffers.rx, fraglen);
+
+ for (fragoff = fraglen; fragoff < len; fragoff += fraglen) {
+ ffa_mem_frag_rx(res, handle_lo, handle_hi, fragoff);
+ if (res->a0 != FFA_MEM_FRAG_TX) {
+ ret = FFA_RET_INVALID_PARAMETERS;
+ goto out_unlock;
+ }
+
+ fraglen = res->a3;
+ memcpy((void *)buf + fragoff, hyp_buffers.rx, fraglen);
+ }
+
ffa_mem_reclaim(res, handle_lo, handle_hi, flags);
if (res->a0 != FFA_SUCCESS)
goto out_unlock;
+ reg = (void *)buf + offset;
/* If the SPMD was happy, then we should be too. */
WARN_ON(ffa_host_unshare_ranges(reg->constituents,
reg->addr_range_cnt));
@@ -569,6 +678,9 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt)
case FFA_FN64_MEM_LEND:
do_ffa_mem_xfer(FFA_FN64_MEM_LEND, &res, host_ctxt);
goto out_handled;
+ case FFA_MEM_FRAG_TX:
+ do_ffa_mem_frag_tx(&res, host_ctxt);
+ goto out_handled;
}
if (ffa_call_supported(func_id))
@@ -584,6 +696,7 @@ int hyp_ffa_init(void *pages)
{
struct arm_smccc_res res;
size_t min_rxtx_sz;
+ void *tx, *rx;
if (kvm_host_psci_config.smccc_version < ARM_SMCCC_VERSION_1_2)
return 0;
@@ -624,10 +737,21 @@ int hyp_ffa_init(void *pages)
if (min_rxtx_sz > PAGE_SIZE)
return -EOPNOTSUPP;
+ tx = pages;
+ pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE;
+ rx = pages;
+ pages += KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE;
+
+ ffa_desc_buf = (struct kvm_ffa_descriptor_buffer) {
+ .buf = pages,
+ .len = PAGE_SIZE *
+ (hyp_ffa_proxy_pages() - (2 * KVM_FFA_MBOX_NR_PAGES)),
+ };
+
hyp_buffers = (struct kvm_ffa_buffers) {
.lock = __HYP_SPIN_LOCK_UNLOCKED,
- .tx = pages,
- .rx = pages + (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE),
+ .tx = tx,
+ .rx = rx,
};
host_buffers = (struct kvm_ffa_buffers) {
--
2.40.1.698.g37aff9b760-goog
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^ permalink raw reply related [flat|nested] 14+ messages in thread* Re: [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM
2023-05-23 10:18 [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Will Deacon
` (9 preceding siblings ...)
2023-05-23 10:18 ` [PATCH v3 10/10] KVM: arm64: pkvm: Add support for fragmented FF-A descriptors Will Deacon
@ 2023-06-07 5:35 ` Oliver Upton
2023-06-08 17:28 ` Will Deacon
10 siblings, 1 reply; 14+ messages in thread
From: Oliver Upton @ 2023-06-07 5:35 UTC (permalink / raw)
To: linux-arm-kernel, Will Deacon
Cc: Oliver Upton, Marc Zyngier, Quentin Perret, Suzuki K Poulose,
Sebastian Ene, James Morse, Fuad Tabba, Sudeep Holla, kernel-team,
kvmarm, Alexandru Elisei
On Tue, 23 May 2023 11:18:17 +0100, Will Deacon wrote:
> This is version three of the pKVM FF-A proxy series previously posted
> here:
>
> v1: https://lore.kernel.org/r/20221116170335.2341003-1-qperret@google.com
> v2: https://lore.kernel.org/r/20230419122051.1341-1-will@kernel.org
>
> Changes since v2 include:
>
> [...]
Applied to kvmarm/next, thanks!
[01/10] KVM: arm64: Block unsafe FF-A calls from the host
https://git.kernel.org/kvmarm/kvmarm/c/048be5fea43d
[02/10] KVM: arm64: Probe FF-A version and host/hyp partition ID during init
https://git.kernel.org/kvmarm/kvmarm/c/12bdce4f4119
[03/10] KVM: arm64: Allocate pages for hypervisor FF-A mailboxes
https://git.kernel.org/kvmarm/kvmarm/c/bc3888a0f4e9
[04/10] KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host
https://git.kernel.org/kvmarm/kvmarm/c/9d0c6a9af9e3
[05/10] KVM: arm64: Add FF-A helpers to share/unshare memory with secure world
https://git.kernel.org/kvmarm/kvmarm/c/f9112eade788
[06/10] KVM: arm64: Handle FFA_MEM_SHARE calls from the host
https://git.kernel.org/kvmarm/kvmarm/c/436090001776
[07/10] KVM: arm64: Handle FFA_MEM_RECLAIM calls from the host
https://git.kernel.org/kvmarm/kvmarm/c/0e3bcb49c135
[08/10] KVM: arm64: Handle FFA_MEM_LEND calls from the host
https://git.kernel.org/kvmarm/kvmarm/c/634d90cf0ac6
[09/10] KVM: arm64: Handle FFA_FEATURES call from the host
https://git.kernel.org/kvmarm/kvmarm/c/20936cd11479
[10/10] KVM: arm64: pkvm: Add support for fragmented FF-A descriptors
https://git.kernel.org/kvmarm/kvmarm/c/0a9f15fd5674
--
Best,
Oliver
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^ permalink raw reply [flat|nested] 14+ messages in thread* Re: [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM
2023-06-07 5:35 ` [PATCH v3 00/10] KVM: arm64: FF-A proxy for pKVM Oliver Upton
@ 2023-06-08 17:28 ` Will Deacon
0 siblings, 0 replies; 14+ messages in thread
From: Will Deacon @ 2023-06-08 17:28 UTC (permalink / raw)
To: Oliver Upton
Cc: linux-arm-kernel, Marc Zyngier, Quentin Perret, Suzuki K Poulose,
Sebastian Ene, James Morse, Fuad Tabba, Sudeep Holla, kernel-team,
kvmarm, Alexandru Elisei
On Wed, Jun 07, 2023 at 05:35:12AM +0000, Oliver Upton wrote:
> On Tue, 23 May 2023 11:18:17 +0100, Will Deacon wrote:
> > This is version three of the pKVM FF-A proxy series previously posted
> > here:
> >
> > v1: https://lore.kernel.org/r/20221116170335.2341003-1-qperret@google.com
> > v2: https://lore.kernel.org/r/20230419122051.1341-1-will@kernel.org
> >
> > Changes since v2 include:
> >
> > [...]
>
> Applied to kvmarm/next, thanks!
Thank you!
Will
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 14+ messages in thread