[PATCH 04/45] KVM: VMX: Support for NMI task gates

Avi Kivity
2008-12-08T11:38:37Z

From: Jan Kiszka <jan.kiszka@siemens.com>

Properly set GUEST_INTR_STATE_NMI and reset nmi_injected when a
task-switch vmexit happened due to a task gate being used for handling
NMIs. Also avoid the false warning about valid vectoring info in
kvm_handle_exit.

Based on original patch by Gleb Natapov.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/vmx.c | 18 +++++++++++++++---
1 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 81cf12b..8d0fc68 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2832,6 +2832,7 @@ static int handle_apic_access(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
unsigned long exit_qualification;
u16 tss_selector;
int reason;
@@ -2839,6 +2840,15 @@ static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
exit_qualification = vmcs_readl(EXIT_QUALIFICATION);

reason = (u32)exit_qualification >> 30;
+ if (reason == TASK_SWITCH_GATE && vmx->vcpu.arch.nmi_injected &&
+ (vmx->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
+ (vmx->idt_vectoring_info & VECTORING_INFO_TYPE_MASK)
+ == INTR_TYPE_NMI_INTR) {
+ vcpu->arch.nmi_injected = false;
+ if (cpu_has_virtual_nmis())
+ vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
+ GUEST_INTR_STATE_NMI);
+ }
tss_selector = exit_qualification;

return kvm_task_switch(vcpu, tss_selector, reason);
@@ -3012,9 +3022,11 @@ static int kvm_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)

if ((vectoring_info & VECTORING_INFO_VALID_MASK) &&
(exit_reason != EXIT_REASON_EXCEPTION_NMI &&
- exit_reason != EXIT_REASON_EPT_VIOLATION))
- printk(KERN_WARNING "%s: unexpected, valid vectoring info and "
- "exit reason is 0x%x\n", __func__, exit_reason);
+ exit_reason != EXIT_REASON_EPT_VIOLATION &&
+ exit_reason != EXIT_REASON_TASK_SWITCH))
+ printk(KERN_WARNING "%s: unexpected, valid vectoring info "
+ "(0x%x) and exit reason is 0x%x\n",
+ __func__, vectoring_info, exit_reason);
if (exit_reason < kvm_vmx_max_exit_handlers
&& kvm_vmx_exit_handlers[exit_reason])
return kvm_vmx_exit_handlers[exit_reason](vcpu, kvm_run);
--
1.6.0.3