Messages in this thread Patch in this message | | | From | Paolo Bonzini <> | Subject | [PATCH 6/9] KVM: cpuid: mask more bits in leaf 0xd and subleaves | Date | Thu, 4 Dec 2014 16:57:11 +0100 |
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- EAX=0Dh, ECX=1: output registers ECX/EDX are reserved.
- EAX=0Dh, ECX>1: output register ECX bit 0 is clear for all the CPUID leaves we support, because variable "supported" comes from XCR0 and not XSS. Bits above 0 are reserved, so ECX is overall zero. Output register EDX is reserved.
Source: Intel Architecture Instruction Set Extensions Programming Reference, ref. number 319433-022
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/x86/kvm/cpuid.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 2f7bc2de9915..644bfe828ce1 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -482,8 +482,14 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, entry[i].ebx = xstate_required_size(supported, true); - } else if (entry[i].eax == 0 || !(supported & mask)) - continue; + } else { + if (entry[i].eax == 0 || !(supported & mask)) + continue; + if (WARN_ON_ONCE(entry[i].ecx & 1)) + continue; + } + entry[i].ecx = 0; + entry[i].edx = 0; entry[i].flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; ++*nent; -- 1.8.3.1
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