This series fixes hot-unplug of virtio devices, which can crash due to dangling pointer accesses.
The current implementation supports guest-initiated hot-unplug via the virtio_bus_destroy_device function, but not hot-unplugging the virtio device by virtue of unplugging its parent container device. The problem is that the callback for the bus implementation to cleanup is placed in the wrong place; it is in virtio_bus_destroy_device, which should be called by the bus, instead of being somewhere in device code. We need to have the callback in device code (for example in dc->exit), so that we invoke it on every unplug action, no matter who starts it. Thus, the series cleans up plugging and unplugging of virtio devices so that it does not need any help from the bus (patches 2-5). It then stops the virtio devices' overriding of dc->exit, moving their cleanup code to the new exit callback in VirtioDeviceClass (patches 6-11). Finally, patch 12 can make virtio-pci implement the device_unplugged callback. A similar dangling-pointer bug is exposed by this change in virtio-ccw. Patch 1 avoids this; it is kept at the beginning to ensure bisectability. Patches 13-30 are Andreas's conversion of virtio to realize/unrealize, which has better error propagation as shown by the small testcase fix. v3->v4: rebased, added Andreas's realize patches on top v2->v3: fix to s390 patch; added Reviewed-by and Cced patch 1 to qemu-stable. v1->v2: remove useless pointer chasing in virtio_pci_notify, add patch 1 to fix breakage reported by Cornelia. Andreas Färber (18): virtio-blk-dataplane: Improve error reporting virtio-9p: QOM realize preparations virtio-blk: QOM realize preparations virtio-serial: QOM realize preparations virtio-net: QOM realize preparations virtio-balloon: QOM realize preparations virtio-rng: QOM realize preparations virtio-scsi: QOM realize preparations virtio: Start converting VirtioDevice to QOM realize virtio-9p: Convert to QOM realize virtio-blk: Convert to QOM realize virtio-serial: Convert to QOM realize virtio-net: Convert to QOM realize virtio-balloon: Convert to QOM realize virtio-rng: Convert to QOM realize virtio-scsi: Convert to QOM realize virtio: Complete converting VirtioDevice to QOM realize virtio: Convert exit to unrealize Paolo Bonzini (12): virtio-ccw: move virtio_ccw_stop_ioeventfd to virtio_ccw_busdev_unplug virtio-bus: remove vdev field virtio-ccw: remove vdev field virtio-pci: remove vdev field virtio-bus: cleanup plug/unplug interface virtio-blk: switch exit callback to VirtioDeviceClass virtio-serial: switch exit callback to VirtioDeviceClass virtio-net: switch exit callback to VirtioDeviceClass virtio-scsi: switch exit callback to VirtioDeviceClass virtio-balloon: switch exit callback to VirtioDeviceClass virtio-rng: switch exit callback to VirtioDeviceClass virtio-pci: add device_unplugged callback hw/9pfs/virtio-9p-device.c | 43 +++++++------- hw/block/dataplane/virtio-blk.c | 30 +++++----- hw/block/dataplane/virtio-blk.h | 5 +- hw/block/virtio-blk.c | 47 ++++++++++------ hw/char/virtio-serial-bus.c | 33 +++++------ hw/net/virtio-net.c | 36 ++++++------ hw/s390x/virtio-ccw.c | 83 +++++++++++++++------------ hw/s390x/virtio-ccw.h | 1 - hw/scsi/vhost-scsi.c | 45 +++++++-------- hw/scsi/virtio-scsi.c | 57 +++++++++---------- hw/virtio/virtio-balloon.c | 32 +++++------ hw/virtio/virtio-bus.c | 80 +++++++++++++++----------- hw/virtio/virtio-mmio.c | 9 +-- hw/virtio/virtio-pci.c | 122 ++++++++++++++++++++++++---------------- hw/virtio/virtio-pci.h | 1 - hw/virtio/virtio-rng.c | 43 +++++++------- hw/virtio/virtio.c | 40 ++++++++----- include/hw/virtio/virtio-bus.h | 22 +++++--- include/hw/virtio/virtio-rng.h | 2 + include/hw/virtio/virtio-scsi.h | 4 +- include/hw/virtio/virtio.h | 8 ++- tests/qdev-monitor-test.c | 4 +- 22 files changed, 413 insertions(+), 334 deletions(-) -- 1.8.3.1