kvm__emulate_io: Don't fall through from IO in to IO out if no handler

If an IO port device has no io_in handler, kvm__emulate_io would fall
through and call the io_out handler instead.  Fix to only call the
handler for the appropriate direction.

If no handler exists, kvm__emulate_io will automatically treat it as an
IO error (due to the default "ret = false").

Signed-off-by: Josh Triplett <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

Author: joshtriplett

ioport.c

@@ -192,7 +192,7 @@ bool kvm__emulate_io(struct kvm_cpu *vcpu, u16 port, void *data, int direction,
 	while (count--) {
 		if (direction == KVM_EXIT_IO_IN && ops->io_in)
 				ret = ops->io_in(entry, vcpu, port, ptr, size);
-		else if (ops->io_out)
+		else if (direction == KVM_EXIT_IO_OUT && ops->io_out)
 				ret = ops->io_out(entry, vcpu, port, ptr, size);
 
 		ptr += size;