kvm: Support MSR register for serial console

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

diff --git a/tools/kvm/early_printk.c b/tools/kvm/early_printk.c
index cb9fe243767565c9829eb0606e08ab2ea7142aeb..0683c299e27609b3de5a7601e17c43be07ff6a04 100644 (file)
--- a/tools/kvm/early_printk.c
+++ b/tools/kvm/early_printk.c
@@ -10,6 +10,7 @@ static int early_serial_base = 0x3f8;  /* ttyS0 */
 
 #define TXR             0       /*  Transmit register (WRITE) */
 #define LSR             5       /*  Line Status               */
+#define MSR            6       /*  Modem Status              */
 
 static bool early_serial_txr_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
 {
@@ -48,8 +49,18 @@ static struct ioport_operations early_serial_lsr_ops = {
        .io_in          = early_serial_lsr_in,
 };
 
+static bool early_serial_msr_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count)
+{
+       return true;
+}
+
+static struct ioport_operations early_serial_msr_ops = {
+       .io_in          = early_serial_msr_in,
+};
+
 void early_printk__init(void)
 {
        ioport__register(early_serial_base + TXR, &early_serial_txr_rxr_ops, 1);
        ioport__register(early_serial_base + LSR, &early_serial_lsr_ops, 1);
+       ioport__register(early_serial_base + MSR, &early_serial_msr_ops, 1);
 }