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KVM: selftests: Move XFD CPUID checking out of __vm_xsave_require_permission()

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Move the kvm_cpu_has() check on X86_FEATURE_XFD out of the helper to
enable off-by-default XSAVE-managed features and into the one test that
currenty requires XFD (XFeature Disable) support.   kvm_cpu_has() uses
kvm_get_supported_cpuid() and thus caches KVM_GET_SUPPORTED_CPUID, and so
using kvm_cpu_has() before ARCH_REQ_XCOMP_GUEST_PERM effectively results
in the test caching stale values, e.g. subsequent checks on AMX_TILE will
get false negatives.

Although off-by-default features are nonsensical without XFD, checking
for XFD virtualization prior to enabling such features isn't strictly
required.

Signed-off-by: Lei Wang <lei4.wang@intel.com>
Fixes: 7fbb653e01fd ("KVM: selftests: Check KVM's supported CPUID, not host CPUID, for XFD")
Link: https://lore.kernel.org/r/20221125023839.315207-1-lei4.wang@intel.com
[sean: add Fixes, reword changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221128225735.3291648-2-seanjc@google.com
This commit is contained in:
Lei Wang 2022-11-28 22:57:32 +00:00 committed by Sean Christopherson
parent 8fcee04213
commit 18eee7bfd1
2 changed files with 1 additions and 2 deletions
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2
tools/testing/selftests/kvm/lib/x86_64/processor.c
View File

@ -563,8 +563,6 @@ void __vm_xsave_require_permission(int bit, const char *name)
.addr = (unsigned long) &bitmask
};
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XFD));
kvm_fd = open_kvm_dev_path_or_exit();
rc = __kvm_ioctl(kvm_fd, KVM_GET_DEVICE_ATTR, &attr);
close(kvm_fd);

1
tools/testing/selftests/kvm/x86_64/amx_test.c
View File

@ -254,6 +254,7 @@ int main(int argc, char *argv[])
/* Create VM */
vm = vm_create_with_one_vcpu(&vcpu, guest_code);
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XFD));
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVE));
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_AMX_TILE));
TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XTILECFG));