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

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
......@@ -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;
}
......
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