[PATCH 6.18.y 0/6] KVM: x86: CPUID faulting fixes and AMD CPUID faulting virtualization

[Anil Altinay <aaltinay@google.com>]

Please backport the following 6 upstream commits to the 6.18.y stable tree:

1. 690dc03859e7 ("KVM: x86: Ignore cpuid faulting in SMM") [v7.1-rc1]
2. cf7d65d1d6f5 ("KVM: x86: Consolidate CPUID fault handling for emulator and interception logic") [v7.2-rc1]
3. be7fd7c3e8bc ("KVM: x86: Prioritize CPUID faulting over CPUID VM-exits in nested VMX") [v7.2-rc1]
4. d1bc99885a59 ("KVM: x86: Remove supports_cpuid_fault() helper") [v7.2-rc1]
5. e93a93f11490 ("KVM: x86: Virtualize AMD CPUID faulting") [v7.2-rc1]
6. b16c2aca369d ("KVM: selftests: Update hwcr_msr_test for CPUID faulting bit") [v7.2-rc1]

Patches 1 and 3 fix bugs in KVM's CPUID faulting virtualization (Fixes:
db2336a80489 ("KVM: x86: virtualize cpuid faulting")), ensuring that
CPUID does not fault in SMM and that CPUID faulting takes precedence
over CPUID VM-exits in nested VMX. Patch 2 is a non-functional refactoring
prerequisite for patch 3.

Patches 4-6 extend KVM's CPUID faulting virtualization (already supported
by KVM on Intel CPUs and by 6.18 host kernels on AMD CPUs via 65f55a301766
("x86/CPU/AMD: Add CPUID faulting support")) to AMD guests via
CPUID.80000021H:EAX.CpuidUserDis[bit 17] and HWCR.CpuidUserDis[bit 35],
allowing guests and container runtimes that rely on arch_prctl(ARCH_SET_CPUID)
to work uniformly across Intel and AMD KVM hosts, along with the
corresponding KVM selftest update.

All patches cherry-pick cleanly to 6.18.y except for a minor context
conflict in patch 2 (arch/x86/include/asm/kvm_host.h) and a u64 vs.
uint64_t type adjustment in patch 6 (tools/testing/selftests/kvm/x86/hwcr_msr_test.c).

Jim Mattson (5):
  KVM: x86: Ignore cpuid faulting in SMM
  KVM: x86: Prioritize CPUID faulting over CPUID VM-exits in nested VMX
  KVM: x86: Remove supports_cpuid_fault() helper
  KVM: x86: Virtualize AMD CPUID faulting
  KVM: selftests: Update hwcr_msr_test for CPUID faulting bit

Sean Christopherson (1):
  KVM: x86: Consolidate CPUID fault handling for emulator and
    interception logic

 arch/x86/include/asm/kvm_host.h               |  1 -
 arch/x86/include/asm/msr-index.h              |  1 +
 arch/x86/kvm/cpuid.c                          |  6 ++-
 arch/x86/kvm/cpuid.h                          | 14 ++++---
 arch/x86/kvm/emulate.c                        |  6 +--
 arch/x86/kvm/kvm_emulate.h                    |  1 +
 arch/x86/kvm/vmx/nested.c                     |  2 +
 arch/x86/kvm/x86.c                            | 39 ++++++++++---------
 .../selftests/kvm/include/x86/processor.h     |  1 +
 .../testing/selftests/kvm/x86/hwcr_msr_test.c |  9 ++++-
 10 files changed, 46 insertions(+), 34 deletions(-)

-- 
2.56.0.385.gd3acb90ef8-goog