Currently virtio_blk driver does not provide discard feature flag, so the filesystems which built on top of the block device will not send discard command. This is okay for HDD backend, but it will impact the performance for SSD backend. Add a feature flag such as VIRTIO_BLK_F_DISCARD to virtio_blk driver is very straightforward, but it will extend the exist virtio_blk protocol, I'm preparing to add this feature, before that, I'd like to get comments or suggestions from community. --- 1.9.3 _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization