kvm,8250: Fix device initial state

This patch fixes 8250 device initial state for registers and IRQ based on what
Qemu does.

Signed-off-by: Pekka Enberg <penberg@kernel.org>

8250-serial.c

@@ -32,8 +32,10 @@ static struct serial8250_device devices[] = {
 		.iobase			= 0x3f8,
 		.irq			= 4,
 
-		.lsr			= UART_LSR_TEMT | UART_LSR_THRE,
 		.iir			= UART_IIR_NO_INT,
+		.lsr			= UART_LSR_TEMT | UART_LSR_THRE,
+		.msr			= UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS,
+		.mcr			= UART_MCR_OUT2,
 	},
 	/* ttyS1 */
 	[1]	= {
@@ -282,13 +284,19 @@ static struct ioport_operations serial8250_ops = {
 	.io_out		= serial8250_out,
 };
 
-void serial8250__init(void)
+static void serial8250__device_init(struct kvm *kvm, struct serial8250_device *dev)
+{
+	ioport__register(dev->iobase, &serial8250_ops, 8);
+	kvm__irq_line(kvm, dev->irq, 0);
+}
+
+void serial8250__init(struct kvm *kvm)
 {
 	unsigned int i;
 
 	for (i = 0; i < ARRAY_SIZE(devices); i++) {
 		struct serial8250_device *dev = &devices[i];
 
-		ioport__register(dev->iobase, &serial8250_ops, 8);
+		serial8250__device_init(kvm, dev);
 	}
 }

include/kvm/8250-serial.h

@@ -3,7 +3,7 @@
 
 struct kvm;
 
-void serial8250__init(void);
-void serial8250__interrupt(struct kvm *self);
+void serial8250__init(struct kvm *kvm);
+void serial8250__interrupt(struct kvm *kvm);
 
 #endif /* KVM__8250_SERIAL_H */

main.c

@@ -164,7 +164,7 @@ int main(int argc, char *argv[])
 	if (single_step)
 		kvm__enable_singlestep(kvm);
 
-	serial8250__init();
+	serial8250__init(kvm);
 	pci__init();
 
 	blk_virtio__init(kvm);