On Tue, 2015-12-01 at 11:59 -0500, Paolo Bonzini wrote: > > What do you think about virtio-nvme+vhost-nvme? > > What would be the advantage over virtio-blk? Multiqueue is not supported > by QEMU but it's already supported by Linux (commit 6a27b656fc).
I expect performance would be better. Seems google cloud VM uses both nvme and virtio-scsi. Not sure if virtio-blk is also used. https://cloud.google.com/compute/docs/disks/local-ssd#runscript > > To me, the advantage of nvme is that it provides more than decent performance > on > unmodified Windows guests, and thanks to your vendor extension can be used > on Linux as well with speeds comparable to virtio-blk. So it's potentially > a very good choice for a cloud provider that wants to support Windows guests > (together with e.g. a fast SAS emulated controller to replace virtio-scsi, > and emulated igb or ixgbe to replace virtio-net). vhost-nvme patches are learned from rts-megasas, which could possibly be a fast SAS emulated controller. https://github.com/Datera/rts-megasas > > Which features are supported by NVMe and not virtio-blk? Rob (CCed), Would you share whether google uses any NVMe specific feature? Thanks.
