qemu/hw/block
Pavel Butsykin 10a06fd65f virtio: sync the dataplane vring state to the virtqueue before virtio_save
When creating snapshot with the dataplane enabled, the snapshot file gets
not the actual state of virtqueue, because the current state is stored in
VirtIOBlockDataPlane. Therefore, before saving snapshot need to sync
the dataplane vring state to the virtqueue. The dataplane will resume its
work at the next notify virtqueue.

When snapshot loads with loadvm we get a message:
VQ 0 size 0x80 Guest index 0x15f5 inconsistent with Host index 0x0:
    delta 0x15f5
error while loading state for instance 0x0 of device
    '0000:00:08.0/virtio-blk'
Error -1 while loading VM state

to reproduce the error I used the following hmp commands:
savevm snap1
loadvm snap1

qemu parameters:
--enable-kvm -smp 4 -m 1024 -drive file=/var/lib/libvirt/images/centos6.4.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,aio=native -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x8,drive=drive-virtio-disk0,id=virtio-disk0 -set device.virtio-disk0.x-data-plane=on

Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Message-id: 1445859777-2982-1-git-send-email-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2015-10-29 17:59:27 +00:00
..
dataplane dataplane: Mark host notifiers' client type as "external" 2015-10-23 18:18:24 +02:00
block.c BlockConf: Call backend functions to detect geometry and blocksizes 2015-03-10 14:02:22 +01:00
cdrom.c bswap.h: Remove cpu_to_be32wu() 2013-11-05 19:57:47 -08:00
ecc.c savevm: Remove all the unneeded version_minimum_id_old (arm) 2014-05-13 16:09:35 +01:00
fdc.c hw/block/fdc: Implement tray status 2015-10-23 18:18:23 +02:00
hd-geometry.c BlockConf: Call backend functions to detect geometry and blocksizes 2015-03-10 14:02:22 +01:00
m25p80.c m25p80: fix s->blk usage before assignment 2015-04-28 15:36:09 +02:00
Makefile.objs block: Always compile virtio-blk dataplane 2014-09-22 11:39:51 +01:00
nand.c block: remove superfluous '\n' around error_report/error_setg 2015-03-10 08:15:33 +03:00
nvme.c hw/block/nvme.c: Use pow2ceil() rather than hand-calculation 2015-09-07 14:19:00 +01:00
nvme.h nvme: implement the Flush command 2015-07-14 15:55:19 +02:00
onenand.c Fix bad error handling after memory_region_init_ram() 2015-09-18 14:39:29 +02:00
pflash_cfi01.c pflash_cfi01: add secure property 2015-06-05 17:36:39 +02:00
pflash_cfi02.c hw: Propagate errors through qdev_prop_set_drive() 2015-03-10 11:18:23 +01:00
tc58128.c shix: Don't require firmware presence for qtest 2013-11-05 17:47:29 +01:00
virtio-blk.c virtio: sync the dataplane vring state to the virtqueue before virtio_save 2015-10-29 17:59:27 +00:00
xen_blkif.h xen_disk: add discard support 2014-05-07 16:18:04 +00:00
xen_disk.c block: Prepare for NULL BDS 2015-10-23 18:18:23 +02:00