On Wed, Jul 24, 2019 at 10:57:30AM +0200, Paolo Bonzini wrote: > On 24/07/19 08:55, Yang Zhong wrote: > > > > The SPDK code i am using is latest version, So, i feel we should > > enable WCE feature in SPDK side by default. thanks for your help! > > Note that enabling the CONFIG_WCE feature has some consequences. > According to the spec: > > - if the VIRTIO_BLK_F_CONFIG_WCE feature was negotiated and the > writeback field in configuration space was 0 all the time between the > submission of the write and its completion, the device MUST ensure that > stable writes are committed to persistent storage before reporting > completion of the write. This means using FUA writes or something like that > > - the device MUST offset VIRTIO_BLK_F_FLUSH if they offer > VIRTIO_BLK_F_CONFIG_WCE > > - if VIRTIO_BLK_F_CONFIG_WCE is negotiated but VIRTIO_BLK_F_FLUSH is > not, the device MUST initialize writeback to 0 > Paolo, thanks for your reminder, these info are very helpful to me:), thanks, Yang.
> Paolo
