Commit 5f41a37b authored Sep 25, 2019 by Jim Mattson Committed by Paolo Bonzini Sep 26, 2019

kvm: x86: Use AMD CPUID semantics for AMD vCPUs



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: bd22f5cf ("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>

parent 43561123

arch/x86/kvm/cpuid.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -998,9 +998,11 @@ 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;

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