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 <avi@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 8f9e77e..53bf6ae 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -129,6 +129,7 @@
int launched;
u8 fail;
u8 cpl;
+ bool nmi_known_unmasked;
u32 exit_intr_info;
u32 idt_vectoring_info;
ulong rflags;
@@ -2959,6 +2960,7 @@
}
++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 @@
{
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 @@
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 @@
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 @@
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 @@
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 @@
*/
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 =