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authorEvgeny Yakovlev <wrfsh@yandex-team.ru>2019-11-05 21:22:17 +0300
committerStefan Hajnoczi <stefanha@redhat.com>2019-12-13 11:22:06 +0000
commit5f2585772fff7ada93cb6691c51603451228a09c (patch)
tree65858f3bf90fecbf987a9364ad1cea6fad0ca91c /bt-vhci.c
parentb0ca999a43a22b38158a222233d3f5881648bb4f (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 'bt-vhci.c')
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