Il 03/07/2012 15:20, Paolo Bonzini ha scritto: > These patches let virtio-blk use the new support for toggling the cache > mode between writethrough and writeback. > > The first patch introduces a new feature bit and configuration field to > do this. The second patch disables writeback caching for guests that do > not negotiate VIRTIO_BLK_F_WCACHE (meaning that they cannot send flush > requests), so that limited or older guests are now safe wrt power losses. > VIRTIO_BLK_F_FLUSH has been introduced in Linux 2.6.32 (in 2009) and was > backported to RHEL/CentOS 5.6 (in 2010). > > The Windows drivers (which work by emulating SCSI on top of virtio-blk) > have bugs in this area, which I reported on the Red Hat Bugzilla as > bugs 837321 and 837324. With these patches they will suffer a > performance hit but gain correctness. > > Paolo Bonzini (2): > virtio-blk: support VIRTIO_BLK_F_CONFIG_WCE > virtio-blk: disable write cache if not negotiated Ping - Anthony, mst? Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
