Patchwork usb: fail usbdevice_create() when there is no USB bus

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Submitter Stefan Hajnoczi
Date Nov. 25, 2012, 3:49 p.m.
Message ID <1353858555-29592-1-git-send-email-stefanha@redhat.com>
Download mbox | patch
Permalink /patch/201646/
State New
Headers show

Comments

Stefan Hajnoczi - Nov. 25, 2012, 3:49 p.m.
Report an error instead of segfaulting when attaching a USB device to a
machine with no USB busses:

  $ qemu-system-arm -machine vexpress-a9 \
      -sd Fedora-17-armhfp-vexpress-mmcblk0.img \
      -kernel vmlinuz-3.4.2-3.fc17.armv7hl \
      -initrd initramfs-3.4.2-3.fc17.armv7hl.img \
      -usbdevice disk:format=raw:test.img

Note that the vexpress-a9 machine does not have a USB host controller.

Reported-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/usb/bus.c | 7 +++++++
 1 file changed, 7 insertions(+)
Gerd Hoffmann - Nov. 27, 2012, 1:11 p.m.
On 11/25/12 16:49, Stefan Hajnoczi wrote:
> Report an error instead of segfaulting when attaching a USB device to a
> machine with no USB busses:
> 
>   $ qemu-system-arm -machine vexpress-a9 \
>       -sd Fedora-17-armhfp-vexpress-mmcblk0.img \
>       -kernel vmlinuz-3.4.2-3.fc17.armv7hl \
>       -initrd initramfs-3.4.2-3.fc17.armv7hl.img \
>       -usbdevice disk:format=raw:test.img
> 
> Note that the vexpress-a9 machine does not have a USB host controller.
> 
> Reported-by: David Abdurachmanov <David.Abdurachmanov@cern.ch>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Patch added to usb patch queue.

thanks,
  Gerd

Patch

diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index 99aac7a..55d0edd 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -590,6 +590,13 @@  USBDevice *usbdevice_create(const char *cmdline)
         return NULL;
     }
 
+    if (!bus) {
+        error_report("Error: no usb bus to attach usbdevice %s, "
+                     "please try -machine usb=on and check that "
+                     "the machine model supports USB", driver);
+        return NULL;
+    }
+
     if (!f->usbdevice_init) {
         if (*params) {
             error_report("usbdevice %s accepts no params", driver);