monitor: Add port write command

Useful for testing hardware emulations or manipulating its state to
stress guest drivers.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/monitor.c b/monitor.c
index c3ef099bda..e38c86e1a3 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1185,6 +1185,25 @@ static void do_ioport_read(Monitor *mon, int count, int format, int size,
                    suffix, addr, size * 2, val);
 }
 
+static void do_ioport_write(Monitor *mon, int count, int format, int size,
+                            int addr, int val)
+{
+    addr &= IOPORTS_MASK;
+
+    switch (size) {
+    default:
+    case 1:
+        cpu_outb(NULL, addr, val);
+        break;
+    case 2:
+        cpu_outw(NULL, addr, val);
+        break;
+    case 4:
+        cpu_outl(NULL, addr, val);
+        break;
+    }
+}
+
 static void do_boot_set(Monitor *mon, const char *bootdevice)
 {
     int res;