diff options
| author | Sean Christopherson <seanjc@google.com> | 2024-11-27 17:33:28 -0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2024-12-18 14:19:22 -0800 |
| commit | ccf4c1d15d5a593bb3a50911ce3e8bb373feddc5 (patch) | |
| tree | cd34c6974945a1ea30bde1c1576a332b8b59360c | |
| parent | 9af04539d474dda4984ff4909d4568e6123c8cba (diff) | |
KVM: x86: Use feature_bit() to clear CONSTANT_TSC when emulating CPUID
When clearing CONSTANT_TSC during CPUID emulation due to a Hyper-V quirk,
use feature_bit() instead of SF() to ensure the bit is actually cleared.
SF() evaluates to zero if the _host_ doesn't support the feature. I.e.
KVM could keep the bit set if userspace advertised CONSTANT_TSC despite
it not being supported in hardware.
Note, translating from a scattered feature to a the hardware version is
done by __feature_translate(), not SF(). The sole purpose of SF() is to
check kernel support for the scattered feature, *before* translation.
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20241128013424.4096668-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index ae0b438a2c99..701bbbf58124 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1651,7 +1651,7 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, *ebx &= ~(F(RTM) | F(HLE)); } else if (function == 0x80000007) { if (kvm_hv_invtsc_suppressed(vcpu)) - *edx &= ~SF(CONSTANT_TSC); + *edx &= ~feature_bit(CONSTANT_TSC); } } else { *eax = *ebx = *ecx = *edx = 0; |