KVM: VMX: Use vmx to inject real-mode interrupts
Instead of injecting real-mode interrupts by writing the interrupt frame into
guest memory, abuse vmx by injecting a software interrupt. We need to
pretend the software interrupt instruction had a length > 0, so we have to
adjust rip backward.
This lets us not to mess with writing guest memory, which is complex and also
sleeps.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/vmx.h b/drivers/kvm/vmx.h
index c84bd37..d757b36 100644
--- a/drivers/kvm/vmx.h
+++ b/drivers/kvm/vmx.h
@@ -233,6 +233,7 @@
#define INTR_TYPE_EXT_INTR (0 << 8) /* external interrupt */
#define INTR_TYPE_EXCEPTION (3 << 8) /* processor exception */
+#define INTR_TYPE_SOFT_INTR (4 << 8) /* software interrupt */
/*
* Exit Qualifications for MOV for Control Register Access