Messages in this thread | | | Date | Mon, 30 Jul 2012 09:31:06 +0200 | From | Paolo Bonzini <> | Subject | Re: [PATCH V3 3/3] virtio-blk: Add bio-based IO path for virtio-blk |
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Il 30/07/2012 06:43, Asias He ha scritto: >> > > Yes. Something like this: > > qemu -drive file=foo.img,cache=writeback/unsafe > > is not safe against power losses also?
cache=writeback and cache=none are safe, cache=unsafe isn't.
> I think we can add REQ_FLUSH & REQ_FUA support to bio path and that > deserves another patch.
You only need to add REQ_FLUSH support. The virtio-blk protocol does not support REQ_FUA, because there's no easy way to do it in userspace.
Paolo
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