[PATCH v11 00/43] KVM: arm64: Nested Virtualization support (FEAT_NV2 only)

[Marc Zyngier <maz@kernel.org>]

This is the 5th drop of NV support on arm64 for this year, and most
probably the last one for this side of Christmas.

For the previous episodes, see [1].

What's changed:

- Drop support for the original FEAT_NV. No existing hardware supports
  it without FEAT_NV2, and the architecture is deprecating the former
  entirely. This results in fewer patches, and a slightly simpler
  model overall.

- Reorganise the series to make it a bit more logical now that FEAT_NV
  is gone.

- Apply the NV idreg restrictions on VM first run rather than on each
  access.

- Make the nested vgic shadow CPU interface a per-CPU structure rather
  than per-vcpu.

- Fix the EL0 timer fastpath

- Work around the architecture deficiencies when trapping WFI from a
  L2 guest.

- Fix sampling of nested vgic state (MISR, ELRSR, EISR)

- Drop the patches that have already been merged (NV trap forwarding,
  per-MMU VTCR)

- Rebased on top of 6.7-rc2 + the FEAT_E2H0 support [2].

The branch containing these patches (and more) is at [3]. As for the
previous rounds, my intention is to take a prefix of this series into
6.8, provided that it gets enough reviewing.

[1] https://lore.kernel.org/r/20230515173103.1017669-1-maz@kernel.org
[2] https://lore.kernel.org/r/20231120123721.851738-1-maz@kernel.org
[3] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=kvm-arm64/nv-6.8-nv2-only

Andre Przywara (1):
  KVM: arm64: nv: vgic: Allow userland to set VGIC maintenance IRQ

Christoffer Dall (2):
  KVM: arm64: nv: Implement nested Stage-2 page table walk logic
  KVM: arm64: nv: Unmap/flush shadow stage 2 page tables

Jintack Lim (3):
  KVM: arm64: nv: Respect virtual HCR_EL2.TWX setting
  KVM: arm64: nv: Respect virtual CPTR_EL2.{TFP,FPEN} settings
  KVM: arm64: nv: Trap and emulate TLBI instructions from virtual EL2

Marc Zyngier (37):
  arm64: cpufeatures: Restrict NV support to FEAT_NV2
  KVM: arm64: nv: Hoist vcpu_has_nv() into is_hyp_ctxt()
  KVM: arm64: nv: Compute NV view of idregs as a one-off
  KVM: arm64: nv: Drop EL12 register traps that are redirected to VNCR
  KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers
  KVM: arm64: nv: Add include containing the VNCR_EL2 offsets
  KVM: arm64: Introduce a bad_trap() primitive for unexpected trap
    handling
  KVM: arm64: nv: Add EL2_REG_VNCR()/EL2_REG_REDIR() sysreg helpers
  KVM: arm64: nv: Map VNCR-capable registers to a separate page
  KVM: arm64: nv: Handle virtual EL2 registers in
    vcpu_read/write_sys_reg()
  KVM: arm64: nv: Handle HCR_EL2.E2H specially
  KVM: arm64: nv: Handle CNTHCTL_EL2 specially
  KVM: arm64: nv: Save/Restore vEL2 sysregs
  KVM: arm64: nv: Configure HCR_EL2 for FEAT_NV2
  KVM: arm64: nv: Support multiple nested Stage-2 mmu structures
  KVM: arm64: nv: Handle shadow stage 2 page faults
  KVM: arm64: nv: Restrict S2 RD/WR permissions to match the guest's
  KVM: arm64: nv: Set a handler for the system instruction traps
  KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2
  KVM: arm64: nv: Hide RAS from nested guests
  KVM: arm64: nv: Add handling of EL2-specific timer registers
  KVM: arm64: nv: Sync nested timer state with FEAT_NV2
  KVM: arm64: nv: Publish emulated timer interrupt state in the
    in-memory state
  KVM: arm64: nv: Load timer before the GIC
  KVM: arm64: nv: Nested GICv3 Support
  KVM: arm64: nv: Don't block in WFI from nested state
  KVM: arm64: nv: Fold GICv3 host trapping requirements into guest setup
  KVM: arm64: nv: Deal with broken VGIC on maintenance interrupt
    delivery
  KVM: arm64: nv: Add handling of FEAT_TTL TLB invalidation
  KVM: arm64: nv: Invalidate TLBs based on shadow S2 TTL-like
    information
  KVM: arm64: nv: Tag shadow S2 entries with nested level
  KVM: arm64: nv: Allocate VNCR page when required
  KVM: arm64: nv: Fast-track 'InHost' exception returns
  KVM: arm64: nv: Fast-track EL1 TLBIs for VHE guests
  KVM: arm64: nv: Use FEAT_ECV to trap access to EL0 timers
  KVM: arm64: nv: Accelerate EL0 timer read accesses when FEAT_ECV is on
  KVM: arm64: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT

 .../virt/kvm/devices/arm-vgic-v3.rst          |  12 +-
 arch/arm64/include/asm/esr.h                  |   1 +
 arch/arm64/include/asm/kvm_arm.h              |   3 +
 arch/arm64/include/asm/kvm_asm.h              |   4 +
 arch/arm64/include/asm/kvm_emulate.h          |  53 +-
 arch/arm64/include/asm/kvm_host.h             | 223 +++-
 arch/arm64/include/asm/kvm_hyp.h              |   2 +
 arch/arm64/include/asm/kvm_mmu.h              |  12 +
 arch/arm64/include/asm/kvm_nested.h           | 130 ++-
 arch/arm64/include/asm/sysreg.h               |   7 +
 arch/arm64/include/asm/vncr_mapping.h         | 102 ++
 arch/arm64/include/uapi/asm/kvm.h             |   1 +
 arch/arm64/kernel/cpufeature.c                |  22 +-
 arch/arm64/kvm/Makefile                       |   4 +-
 arch/arm64/kvm/arch_timer.c                   | 115 +-
 arch/arm64/kvm/arm.c                          |  46 +-
 arch/arm64/kvm/at.c                           | 219 ++++
 arch/arm64/kvm/emulate-nested.c               |  48 +-
 arch/arm64/kvm/handle_exit.c                  |  29 +-
 arch/arm64/kvm/hyp/include/hyp/switch.h       |   8 +-
 arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h    |   5 +-
 arch/arm64/kvm/hyp/nvhe/switch.c              |   2 +-
 arch/arm64/kvm/hyp/nvhe/sysreg-sr.c           |   2 +-
 arch/arm64/kvm/hyp/vgic-v3-sr.c               |   6 +-
 arch/arm64/kvm/hyp/vhe/switch.c               | 211 +++-
 arch/arm64/kvm/hyp/vhe/sysreg-sr.c            | 133 ++-
 arch/arm64/kvm/hyp/vhe/tlb.c                  |  83 ++
 arch/arm64/kvm/mmu.c                          | 248 ++++-
 arch/arm64/kvm/nested.c                       | 813 ++++++++++++++-
 arch/arm64/kvm/reset.c                        |   7 +
 arch/arm64/kvm/sys_regs.c                     | 978 ++++++++++++++++--
 arch/arm64/kvm/vgic/vgic-init.c               |  35 +
 arch/arm64/kvm/vgic/vgic-kvm-device.c         |  29 +-
 arch/arm64/kvm/vgic/vgic-v3-nested.c          | 270 +++++
 arch/arm64/kvm/vgic/vgic-v3.c                 |  35 +-
 arch/arm64/kvm/vgic/vgic.c                    |  29 +
 arch/arm64/kvm/vgic/vgic.h                    |  10 +
 arch/arm64/tools/cpucaps                      |   2 +
 include/clocksource/arm_arch_timer.h          |   4 +
 include/kvm/arm_arch_timer.h                  |  19 +
 include/kvm/arm_vgic.h                        |  16 +
 include/uapi/linux/kvm.h                      |   1 +
 tools/arch/arm/include/uapi/asm/kvm.h         |   1 +
 43 files changed, 3725 insertions(+), 255 deletions(-)
 create mode 100644 arch/arm64/include/asm/vncr_mapping.h
 create mode 100644 arch/arm64/kvm/at.c
 create mode 100644 arch/arm64/kvm/vgic/vgic-v3-nested.c

-- 
2.39.2