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Commit 5f41a37b authored by Jim Mattson's avatar Jim Mattson Committed by Paolo Bonzini
Browse files

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: default avatarJim Mattson <jmattson@google.com>
Fixes: bd22f5cf ("KVM: move and fix substitue search for missing CPUID entries")
Reviewed-by: default avatarMarc Orr <marcorr@google.com>
Reviewed-by: default avatarPeter Shier <pshier@google.com>
Reviewed-by: default avatarJacob Xu <jacobhxu@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarPaolo 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;