KVM: nSVM: inject exceptions via svm_check_nested_events

This allows exceptions injected by the emulator to be properly delivered
as vmexits.  The code also becomes simpler, because we can just let all
L0-intercepted exceptions go through the usual path.  In particular, our
emulation of the VMX #DB exit qualification is very much simplified,
because the vmexit injection path can use kvm_deliver_exception_payload
to update DR6.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/svm.h

@@ -86,6 +86,7 @@ struct nested_state {
 	u64 hsave_msr;
 	u64 vm_cr_msr;
 	u64 vmcb;
+	u32 host_intercept_exceptions;
 
 	/* These are the merged vectors */
 	u32 *msrpm;