From: Jim Mattson jmattson@google.com
[ Upstream commit 5f41a37b151f6459e0b650a2f4d1d59b6c02d1ab ]
When the guest CPUID information represents an AMD vCPU, return all zeroes for queries of undefined CPUID leaves, whether or not they are in range.
Signed-off-by: Jim Mattson jmattson@google.com Fixes: bd22f5cfcfe8f6 ("KVM: move and fix substitue search for missing CPUID entries") Reviewed-by: Marc Orr marcorr@google.com Reviewed-by: Peter Shier pshier@google.com Reviewed-by: Jacob Xu jacobhxu@google.com Cc: Sean Christopherson sean.j.christopherson@intel.com Cc: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kvm/cpuid.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index f3c49dc423895..3d480ec143284 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -893,9 +893,11 @@ bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, /* * Intel CPUID semantics treats any query for an out-of-range * leaf as if the highest basic leaf (i.e. CPUID.0H:EAX) were - * requested. + * requested. AMD CPUID semantics returns all zeroes for any + * undefined leaf, whether or not the leaf is in range. */ - if (!entry && check_limit && !cpuid_function_in_range(vcpu, function)) { + if (!entry && check_limit && !guest_cpuid_is_amd(vcpu) && + !cpuid_function_in_range(vcpu, function)) { max = kvm_find_cpuid_entry(vcpu, 0, 0); if (max) { function = max->eax;