From f2485b3e0c6c0aa3a9546babc2fad3739e964ebb Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 15 Jun 2016 15:23:11 +0200 Subject: KVM: x86: use guest_exit_irqoff This gains a few clock cycles per vmexit. On Intel there is no need anymore to enable the interrupts in vmx_handle_external_intr, since we are using the "acknowledge interrupt on exit" feature. AMD needs to do that, and must be careful to avoid the interrupt shadow. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/kvm/svm.c') diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 5ff292778110..5bfdbbf1ce79 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -4935,6 +4935,12 @@ out: static void svm_handle_external_intr(struct kvm_vcpu *vcpu) { local_irq_enable(); + /* + * We must have an instruction with interrupts enabled, so + * the timer interrupt isn't delayed by the interrupt shadow. + */ + asm("nop"); + local_irq_disable(); } static void svm_sched_in(struct kvm_vcpu *vcpu, int cpu) -- cgit v1.2.3