KVM: Non-atomic interrupt injection

Change the interrupt injection code to work from preemptible, interrupts
enabled context.  This works by adding a ->cancel_injection() operation
that undoes an injection in case we were not able to actually enter the guest
(this condition could never happen with atomic injection).

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 3237f6cc930d..70af3db372d7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3895,6 +3895,16 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
                                   IDT_VECTORING_ERROR_CODE);
 }
 
+static void vmx_cancel_injection(struct kvm_vcpu *vcpu)
+{
+        __vmx_complete_interrupts(to_vmx(vcpu),
+                                  vmcs_read32(VM_ENTRY_INTR_INFO_FIELD),
+                                  VM_ENTRY_INSTRUCTION_LEN,
+                                  VM_ENTRY_EXCEPTION_ERROR_CODE);
+
+        vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, 0);
+}
+
 /*
  * Failure to inject an interrupt should give us the information
  * in IDT_VECTORING_INFO_FIELD.  However, if the failure occurs
@@ -4348,6 +4358,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
         .set_irq = vmx_inject_irq,
         .set_nmi = vmx_inject_nmi,
         .queue_exception = vmx_queue_exception,
+        .cancel_injection = vmx_cancel_injection,
         .interrupt_allowed = vmx_interrupt_allowed,
         .nmi_allowed = vmx_nmi_allowed,
         .get_nmi_mask = vmx_get_nmi_mask,