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@xxxxxxxxxx>
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 097bdc022d0f..776f24408fa3 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -1630,7 +1630,7 @@ 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;
--
2.47.0.338.g60cca15819-goog
