Commit 0497d2ac authored by Sean Christopherson's avatar Sean Christopherson
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KVM: VMX: Check KVM CPU caps, not just VMX MSR support, for XSAVE enabling 



Check KVM CPU capabilities instead of raw VMX support for XSAVES when
determining whether or not XSAVER can/should be exposed to the guest.
Practically speaking, it's nonsensical/impossible for a CPU to support
"enable XSAVES" without XSAVES being supported natively.  The real
motivation for checking kvm_cpu_cap_has() is to allow using the governed
feature's standard check-and-set logic.

Reviewed-by: default avatarYuan Yao <yuan.yao@intel.com>
Link: https://lore.kernel.org/r/20230815203653.519297-5-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 1143c0b8

arch/x86/kvm/vmx/vmx.c

+1 −1
Original line number Diff line number Diff line
@@ -7743,7 +7743,7 @@ static void vmx_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) 
	 * to the guest.  XSAVES depends on CR4.OSXSAVE, and CR4.OSXSAVE can be

	 * set if and only if XSAVE is supported.

	 */

	vcpu->arch.xsaves_enabled = cpu_has_vmx_xsaves() &&

	vcpu->arch.xsaves_enabled = kvm_cpu_cap_has(X86_FEATURE_XSAVES) &&

				    boot_cpu_has(X86_FEATURE_XSAVE) &&

				    guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&

				    guest_cpuid_has(vcpu, X86_FEATURE_XSAVES);