diff options
| author | Evgeny Yakovlev <wrfsh@yandex-team.ru> | 2019-11-05 21:22:17 +0300 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2019-12-13 11:22:06 +0000 |
| commit | 5f2585772fff7ada93cb6691c51603451228a09c (patch) | |
| tree | 65858f3bf90fecbf987a9364ad1cea6fad0ca91c /hw/block | |
| parent | b0ca999a43a22b38158a222233d3f5881648bb4f (diff) | |
virtio-blk: advertise F_WCE (F_FLUSH) if F_CONFIG_WCE is advertised
Virtio spec 1.1 (and earlier), 5.2.5.2 Driver Requirements: Device
Initialization:
"Devices SHOULD always offer VIRTIO_BLK_F_FLUSH, and MUST offer it if
they offer VIRTIO_BLK_F_CONFIG_WCE"
Currently F_CONFIG_WCE and F_WCE are not connected to each other.
Qemu will advertise F_CONFIG_WCE if config-wce argument is
set for virtio-blk device. And F_WCE is advertised only if
underlying block backend actually has it's caching enabled.
Fix this by advertising F_WCE if F_CONFIG_WCE is also advertised.
To preserve backwards compatibility with newer machine types make this
behaviour governed by "x-enable-wce-if-config-wce" virtio-blk-device
property and introduce hw_compat_4_2 with new property being off by
default for all machine types <= 4.2 (but don't introduce 4.3
machine type itself yet).
Signed-off-by: Evgeny Yakovlev <wrfsh@yandex-team.ru>
Message-Id: <1572978137-189218-1-git-send-email-wrfsh@yandex-team.ru>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/block')
| -rw-r--r-- | hw/block/virtio-blk.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 4c357d2928..d62e6377c2 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -991,7 +991,9 @@ static uint64_t virtio_blk_get_features(VirtIODevice *vdev, uint64_t features, virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); } - if (blk_enable_write_cache(s->blk)) { + if (blk_enable_write_cache(s->blk) || + (s->conf.x_enable_wce_if_config_wce && + virtio_has_feature(features, VIRTIO_BLK_F_CONFIG_WCE))) { virtio_add_feature(&features, VIRTIO_BLK_F_WCE); } if (blk_is_read_only(s->blk)) { @@ -1270,6 +1272,8 @@ static Property virtio_blk_properties[] = { conf.max_discard_sectors, BDRV_REQUEST_MAX_SECTORS), DEFINE_PROP_UINT32("max-write-zeroes-sectors", VirtIOBlock, conf.max_write_zeroes_sectors, BDRV_REQUEST_MAX_SECTORS), + DEFINE_PROP_BOOL("x-enable-wce-if-config-wce", VirtIOBlock, + conf.x_enable_wce_if_config_wce, true), DEFINE_PROP_END_OF_LIST(), }; |