From 3280ea8edede3814553aa19fa27a58daedd48ad9 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Thu, 3 May 2018 08:29:32 +0200 Subject: usb-host: skip open on pending postload bh usb-host emulates a device unplug after live migration, because the device state is unknown and unplug/replug makes sure the guest re-initializes the device into a working state. This can't be done in post-load though, so post-load just schedules a bottom half which executes after vmload is complete. It can happen that the device autoscan timer hits the race window between scheduling and running the bottom half, which in turn can triggers an assert(). Fix that issue by just ignoring the usb_host_open() call in case the bottom half didn't execute yet. Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1572851 Signed-off-by: Gerd Hoffmann Message-id: 20180503062932.17233-1-kraxel@redhat.com --- hw/usb/host-libusb.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c index dc0a8fe295..f31e9cbbb8 100644 --- a/hw/usb/host-libusb.c +++ b/hw/usb/host-libusb.c @@ -102,6 +102,7 @@ struct USBHostDevice { /* callbacks & friends */ QEMUBH *bh_nodev; QEMUBH *bh_postld; + bool bh_postld_pending; Notifier exit; /* request queues */ @@ -870,6 +871,10 @@ static int usb_host_open(USBHostDevice *s, libusb_device *dev) int rc; Error *local_err = NULL; + if (s->bh_postld_pending) { + return -1; + } + trace_usb_host_open_started(bus_num, addr); if (s->dh != NULL) { @@ -1528,6 +1533,7 @@ static void usb_host_post_load_bh(void *opaque) if (udev->attached) { usb_device_detach(udev); } + dev->bh_postld_pending = false; usb_host_auto_check(NULL); } @@ -1539,6 +1545,7 @@ static int usb_host_post_load(void *opaque, int version_id) dev->bh_postld = qemu_bh_new(usb_host_post_load_bh, dev); } qemu_bh_schedule(dev->bh_postld); + dev->bh_postld_pending = true; return 0; } -- cgit v1.2.1