vhost-user-blk: dynamically resize config space based on features
Make vhost-user-blk backwards compatible when migrating from older VMs
running with modern features turned off, the same way it was done for
virtio-blk in 20764be0421c ("virtio-blk: set config size depending on the features enabled")
It's currently impossible to migrate from an older VM with
vhost-user-blk (with disable-legacy=off) because of errors like this:
qemu-system-x86_64: get_pci_config_device: Bad config data: i=0x10 read: 41 device: 1 cmask: ff wmask: 80 w1cmask:0
qemu-system-x86_64: Failed to load PCIDevice:config
qemu-system-x86_64: Failed to load virtio-blk:virtio
qemu-system-x86_64: error while loading state for instance 0x0 of device '0000:00:05.0:00.0:02.0/virtio-blk'
qemu-system-x86_64: load of migration failed: Invalid argument
This is caused by the newer (destination) VM requiring a bigger BAR0
alignment because it has to cover a bigger configuration space, which
isn't actually needed since those additional config fields are not
active (write-zeroes/discard).
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Message-Id: <20220906073111.353245-6-d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 05b7580..8ae2e43 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2281,11 +2281,13 @@
F: contrib/vhost-user-blk/
F: contrib/vhost-user-scsi/
F: hw/block/vhost-user-blk.c
+F: hw/block/virtio-blk-common.c
F: hw/scsi/vhost-user-scsi.c
F: hw/virtio/vhost-user-blk-pci.c
F: hw/virtio/vhost-user-scsi-pci.c
F: include/hw/virtio/vhost-user-blk.h
F: include/hw/virtio/vhost-user-scsi.h
+F: include/hw/virtio/virtio-blk-common.h
vhost-user-gpu
M: Marc-André Lureau <marcandre.lureau@redhat.com>
