usb-host: scan for usb devices when the vm starts

Commit a844ed842d9a9d929645c09ae0f52f753d7a02e0 leads to usb-host
detecting devices not right after qemu startup because the guest
isn't running yet.  Instead they are found on the first of the
regular usb device poll runs.  Which is too late for seabios to see
them, so booting from usb sticks fails.

Fix this by adding a vm state change handler which triggers a device
scan when the vm is started.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/hw/usb/host-linux.c b/hw/usb/host-linux.c
index ca3e24a850cf5cb86e845e615c712f056b6e57a8..5bc77b2feccd58866cb7714918c5afb1be14676d 100644 (file)
--- a/hw/usb/host-linux.c
+++ b/hw/usb/host-linux.c
@@ -1738,6 +1738,7 @@ static int usb_host_scan(void *opaque, USBScanFunc *func)
 }
 
 static QEMUTimer *usb_auto_timer;
+static VMChangeStateEntry *usb_vmstate;
 
 static int usb_host_auto_scan(void *opaque, int bus_num,
                               int addr, const char *port,
@@ -1792,6 +1793,13 @@ static int usb_host_auto_scan(void *opaque, int bus_num,
     return 0;
 }
 
+static void usb_host_vm_state(void *unused, int running, RunState state)
+{
+    if (running) {
+        usb_host_auto_check(unused);
+    }
+}
+
 static void usb_host_auto_check(void *unused)
 {
     struct USBHostDevice *s;
@@ -1820,6 +1828,9 @@ static void usb_host_auto_check(void *unused)
         }
     }
 
+    if (!usb_vmstate) {
+        usb_vmstate = qemu_add_vm_change_state_handler(usb_host_vm_state, NULL);
+    }
     if (!usb_auto_timer) {
         usb_auto_timer = qemu_new_timer_ms(rt_clock, usb_host_auto_check, NULL);
         if (!usb_auto_timer) {