Queue pending exceptions in the 'struct vcpu' instead of directly updating the

processor-specific VMCS or VMCB. The pending exception will be delivered right
before entering the guest.

The order of event injection into the guest is:
- hardware exception
- NMI
- maskable interrupt

In the Intel VT-x case, a pending NMI or interrupt will enable the interrupt
window-exiting and inject it as soon as possible after the hardware exception
is injected. Also since interrupts are inherently asynchronous, injecting
them after the hardware exception should not affect correctness from the
guest perspective.

Rename the unused ioctl VM_INJECT_EVENT to VM_INJECT_EXCEPTION and restrict
it to only deliver x86 hardware exceptions. This new ioctl is now used to
inject a protection fault when the guest accesses an unimplemented MSR.

Discussed with:	grehan, jhb
Reviewed by:	jhb

2 files changed, 15 insertions, 20 deletions

diff --git a/lib/libvmmapi/vmmapi.c b/lib/libvmmapi/vmmapi.c
index eba3367..7198c99 100644
--- a/lib/libvmmapi/vmmapi.c
+++ b/lib/libvmmapi/vmmapi.c
@@ -343,35 +343,32 @@ vm_run(struct vmctx *ctx, int vcpu, uint64_t rip, struct vm_exit *vmexit)
 }
 
 static int
-vm_inject_event_real(struct vmctx *ctx, int vcpu, enum vm_event_type type,
-		     int vector, int error_code, int error_code_valid)
+vm_inject_exception_real(struct vmctx *ctx, int vcpu, int vector,
+    int error_code, int error_code_valid)
 {
-	struct vm_event ev;
+	struct vm_exception exc;
 
-	bzero(&ev, sizeof(ev));
-	ev.cpuid = vcpu;
-	ev.type = type;
-	ev.vector = vector;
-	ev.error_code = error_code;
-	ev.error_code_valid = error_code_valid;
+	bzero(&exc, sizeof(exc));
+	exc.cpuid = vcpu;
+	exc.vector = vector;
+	exc.error_code = error_code;
+	exc.error_code_valid = error_code_valid;
 
-	return (ioctl(ctx->fd, VM_INJECT_EVENT, &ev));
+	return (ioctl(ctx->fd, VM_INJECT_EXCEPTION, &exc));
 }
 
 int
-vm_inject_event(struct vmctx *ctx, int vcpu, enum vm_event_type type,
-		int vector)
+vm_inject_exception(struct vmctx *ctx, int vcpu, int vector)
 {
 
-	return (vm_inject_event_real(ctx, vcpu, type, vector, 0, 0));
+	return (vm_inject_exception_real(ctx, vcpu, vector, 0, 0));
 }
 
 int
-vm_inject_event2(struct vmctx *ctx, int vcpu, enum vm_event_type type,
-		 int vector, int error_code)
+vm_inject_exception2(struct vmctx *ctx, int vcpu, int vector, int errcode)
 {
 
-	return (vm_inject_event_real(ctx, vcpu, type, vector, error_code, 1));
+	return (vm_inject_exception_real(ctx, vcpu, vector, errcode, 1));
 }
 
 int
diff --git a/lib/libvmmapi/vmmapi.h b/lib/libvmmapi/vmmapi.h
index 4a3db5d..dcb5a98 100644
--- a/lib/libvmmapi/vmmapi.h
+++ b/lib/libvmmapi/vmmapi.h
@@ -62,10 +62,8 @@ int	vm_get_register(struct vmctx *ctx, int vcpu, int reg, uint64_t *retval);
 int	vm_run(struct vmctx *ctx, int vcpu, uint64_t rip,
 	       struct vm_exit *ret_vmexit);
 int	vm_apicid2vcpu(struct vmctx *ctx, int apicid);
-int	vm_inject_event(struct vmctx *ctx, int vcpu, enum vm_event_type type,
-			int vector);
-int	vm_inject_event2(struct vmctx *ctx, int vcpu, enum vm_event_type type,
-			 int vector, int error_code);
+int	vm_inject_exception(struct vmctx *ctx, int vcpu, int vec);
+int	vm_inject_exception2(struct vmctx *ctx, int vcpu, int vec, int errcode);
 int	vm_lapic_irq(struct vmctx *ctx, int vcpu, int vector);
 int	vm_lapic_local_irq(struct vmctx *ctx, int vcpu, int vector);
 int	vm_lapic_msi(struct vmctx *ctx, uint64_t addr, uint64_t msg);