From 9d58b93192065f4b2ba6b880e9b0dab0bc11d0ba Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 7 Mar 2011 16:52:07 +0200 Subject: [PATCH] KVM: VMX: Avoid vmx_recover_nmi_blocking() when unneeded When we haven't injected an interrupt, we don't need to recover the nmi blocking state (since the guest can't set it by itself). This allows us to avoid a VMREAD later on. Signed-off-by: Avi Kivity --- arch/x86/kvm/vmx.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8f9e77edc01..53bf6ae493e 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -129,6 +129,7 @@ struct vcpu_vmx { int launched; u8 fail; u8 cpl; + bool nmi_known_unmasked; u32 exit_intr_info; u32 idt_vectoring_info; ulong rflags; @@ -2959,6 +2960,7 @@ static void vmx_inject_nmi(struct kvm_vcpu *vcpu) } ++vcpu->stat.nmi_injections; + vmx->nmi_known_unmasked = false; if (vmx->rmode.vm86_active) { if (kvm_inject_realmode_interrupt(vcpu, NMI_VECTOR) != EMULATE_DONE) kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu); @@ -2983,6 +2985,8 @@ static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu) { if (!cpu_has_virtual_nmis()) return to_vmx(vcpu)->soft_vnmi_blocked; + if (to_vmx(vcpu)->nmi_known_unmasked) + return false; return vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) & GUEST_INTR_STATE_NMI; } @@ -2996,6 +3000,7 @@ static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked) vmx->vnmi_blocked_time = 0; } } else { + vmx->nmi_known_unmasked = !masked; if (masked) vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); @@ -3527,9 +3532,11 @@ static int handle_task_switch(struct kvm_vcpu *vcpu) switch (type) { case INTR_TYPE_NMI_INTR: vcpu->arch.nmi_injected = false; - if (cpu_has_virtual_nmis()) + if (cpu_has_virtual_nmis()) { vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); + vmx->nmi_known_unmasked = false; + } break; case INTR_TYPE_EXT_INTR: case INTR_TYPE_SOFT_INTR: @@ -3916,6 +3923,8 @@ static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx) idtv_info_valid = vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK; if (cpu_has_virtual_nmis()) { + if (vmx->nmi_known_unmasked) + return; unblock_nmi = (exit_intr_info & INTR_INFO_UNBLOCK_NMI) != 0; vector = exit_intr_info & INTR_INFO_VECTOR_MASK; /* @@ -3932,6 +3941,10 @@ static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx) vector != DF_VECTOR && !idtv_info_valid) vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); + else + vmx->nmi_known_unmasked = + !(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) + & GUEST_INTR_STATE_NMI); } else if (unlikely(vmx->soft_vnmi_blocked)) vmx->vnmi_blocked_time += ktime_to_ns(ktime_sub(ktime_get(), vmx->entry_time)); @@ -3970,6 +3983,7 @@ static void __vmx_complete_interrupts(struct vcpu_vmx *vmx, */ vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI); + vmx->nmi_known_unmasked = true; break; case INTR_TYPE_SOFT_EXCEPTION: vmx->vcpu.arch.event_exit_inst_len = -- 2.20.1