usb-host: live migration support

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Gerd Hoffmann 2012-06-08 13:02:16 +02:00
parent a844ed842d
commit a229c0535b

View file

@ -111,6 +111,7 @@ typedef struct USBHostDevice {
uint32_t iso_urb_count;
uint32_t options;
Notifier exit;
QEMUBH *bh;
struct endp_data ep_in[USB_MAX_ENDPOINTS];
struct endp_data ep_out[USB_MAX_ENDPOINTS];
@ -1421,6 +1422,43 @@ static void usb_host_exit_notifier(struct Notifier *n, void *data)
}
}
/*
* This is *NOT* about restoring state. We have absolutely no idea
* what state the host device is in at the moment and whenever it is
* still present in the first place. Attemping to contine where we
* left off is impossible.
*
* What we are going to to to here is emulate a surprise removal of
* the usb device passed through, then kick host scan so the device
* will get re-attached (and re-initialized by the guest) in case it
* is still present.
*
* As the device removal will change the state of other devices (usb
* host controller, most likely interrupt controller too) we have to
* wait with it until *all* vmstate is loaded. Thus post_load just
* kicks a bottom half which then does the actual work.
*/
static void usb_host_post_load_bh(void *opaque)
{
USBHostDevice *dev = opaque;
if (dev->fd != -1) {
usb_host_close(dev);
}
if (dev->dev.attached) {
usb_device_detach(&dev->dev);
}
usb_host_auto_check(NULL);
}
static int usb_host_post_load(void *opaque, int version_id)
{
USBHostDevice *dev = opaque;
qemu_bh_schedule(dev->bh);
return 0;
}
static int usb_host_initfn(USBDevice *dev)
{
USBHostDevice *s = DO_UPCAST(USBHostDevice, dev, dev);
@ -1432,6 +1470,7 @@ static int usb_host_initfn(USBDevice *dev)
QTAILQ_INSERT_TAIL(&hostdevs, s, next);
s->exit.notify = usb_host_exit_notifier;
qemu_add_exit_notifier(&s->exit);
s->bh = qemu_bh_new(usb_host_post_load_bh, s);
usb_host_auto_check(NULL);
if (s->match.bus_num != 0 && s->match.port != NULL) {
@ -1443,7 +1482,13 @@ static int usb_host_initfn(USBDevice *dev)
static const VMStateDescription vmstate_usb_host = {
.name = "usb-host",
.unmigratable = 1,
.version_id = 1,
.minimum_version_id = 1,
.post_load = usb_host_post_load,
.fields = (VMStateField[]) {
VMSTATE_USB_DEVICE(dev, USBHostDevice),
VMSTATE_END_OF_LIST()
}
};
static Property usb_host_dev_properties[] = {