virtio-console: Add some trace events

Add some trace events for messages passed between the char layer and the
virtio-serial bus.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>

hw/virtio-console.c

@@ -12,6 +12,7 @@
 
 #include "qemu-char.h"
 #include "qemu-error.h"
+#include "trace.h"
 #include "virtio-serial.h"
 
 typedef struct VirtConsole {
@@ -24,8 +25,12 @@ typedef struct VirtConsole {
 static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)
 {
     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
+    ssize_t ret;
 
-    return qemu_chr_write(vcon->chr, buf, len);
+    ret = qemu_chr_write(vcon->chr, buf, len);
+
+    trace_virtio_console_flush_buf(port->id, len, ret);
+    return ret;
 }
 
 /* Callback function that's called when the guest opens the port */
@@ -57,6 +62,7 @@ static void chr_read(void *opaque, const uint8_t *buf, int size)
 {
     VirtConsole *vcon = opaque;
 
+    trace_virtio_console_chr_read(vcon->port.id, size);
     virtio_serial_write(&vcon->port, buf, size);
 }
 
@@ -64,6 +70,7 @@ static void chr_event(void *opaque, int event)
 {
     VirtConsole *vcon = opaque;
 
+    trace_virtio_console_chr_event(vcon->port.id, event);
     switch (event) {
     case CHR_EVENT_OPENED:
         virtio_serial_open(&vcon->port);

trace-events

@@ -52,6 +52,11 @@ disable virtio_serial_throttle_port(unsigned int port, bool throttle) "port %u,
 disable virtio_serial_handle_control_message(uint16_t event, uint16_t value) "event %u, value %u"
 disable virtio_serial_handle_control_message_port(unsigned int port) "port %u"
 
+# hw/virtio-console.c
+disable virtio_console_flush_buf(unsigned int port, size_t len, ssize_t ret) "port %u, in_len %zu, out_len %zd"
+disable virtio_console_chr_read(unsigned int port, int size) "port %u, size %d"
+disable virtio_console_chr_event(unsigned int port, int event) "port %u, event %d"
+
 # block.c
 disable multiwrite_cb(void *mcb, int ret) "mcb %p ret %d"
 disable bdrv_aio_multiwrite(void *mcb, int num_callbacks, int num_reqs) "mcb %p num_callbacks %d num_reqs %d"