[v2,0/6] Clean up the supported xfeatures

Message

Aaron Lewis Dec. 30, 2022, 4:24 p.m. UTC

Make sure the supported xfeatures, i.e. EDX:EAX of CPUID.(EAX=0DH,ECX=0),
for MPX, AVX-512, and AMX are in a valid state and follow the rules
outlined in the SDM vol 1, section 13.3 ENABLING THE XSAVE FEATURE SET
AND XSAVE-ENABLED FEATURES.  While those rules apply to the enabled
xfeatures, i.e. XCR0, use them to set the supported xfeatures.  That way
if they are used by userspace or a guest to set the enabled xfeatures,
they won't cause a #GP.  

A test is then added to verify the supported xfeatures are in this
sanitied state.

Aaron Lewis (6):
  KVM: x86: Clear all MPX xfeatures if they are not all set
  KVM: x86: Clear all AVX-512 xfeatures if they are not all set
  KVM: x86: Clear all AMX xfeatures if they are not all set
  KVM: selftests: Hoist XGETBV and XSETBV to make them more accessible
  KVM: selftests: Add XFEATURE flags to common code
  KVM: selftests: Add XCR0 Test

 arch/x86/kvm/cpuid.c                          |  19 +++
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/include/x86_64/processor.h  |  35 +++++
 tools/testing/selftests/kvm/x86_64/amx_test.c |  46 ++-----
 .../selftests/kvm/x86_64/xcr0_cpuid_test.c    | 121 ++++++++++++++++++
 5 files changed, 187 insertions(+), 35 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/x86_64/xcr0_cpuid_test.c