Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 476b7ada authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Radim Krčmář
Browse files

KVM: x86: avoid unnecessary XSETBV on guest entry 



xsetbv can be expensive when running on nested virtualization, try to
avoid it.

Reviewed-by: default avatarJim Mattson <jmattson@google.com>
Reviewed-by: default avatarWanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: default avatarQuan Xu <quan.xu0@gmail.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent efdab992

arch/x86/kvm/x86.c

+2 −1
Original line number Diff line number Diff line
@@ -702,6 +702,7 @@ static void kvm_load_guest_xcr0(struct kvm_vcpu *vcpu) 
	if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE) &&

			!vcpu->guest_xcr0_loaded) {

		/* kvm_set_xcr() also depends on this */

		if (vcpu->arch.xcr0 != host_xcr0)

			xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0);

		vcpu->guest_xcr0_loaded = 1;

	}