On Tue, Mar 20, 2018 at 07:30:04PM +0300, Edgar Kaziakhmedov wrote:
On 3/20/18 6:34 PM, Paolo Bonzini wrote:
On 20/03/2018 15:45, Edgar Kaziakhmedov wrote:
As I understood from
Stefan description, it is expected to change significantly
the approach we use to interact with BlockDriverState.
I don't think the change is very large actually, at least for on-disk
devices. I haven't yet considered network devices such as libiscsi or ceph.
Well, in that case, I will keep working on per-queue iothreads with an
existing interface.
I asked because it might be reasonable to create BlockBackend device for
each queue context and
use them independently to avoid some additional locks and synchronization.
On the other hand, it can lead to multiple
opening of the same image, but as I said it doesn't seem to be a problem for
the simplest formats such as raw.
The special case for raw approach is not suitable for upstream QEMU.
It's what we started with in -device virtio-blk,x-data-plane=on (see the
old dataplane implementation in QEMU v1.4).