From: Paolo Bonzini <pbonzini@redhat.com>
To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
Anthony Liguori <aliguori@us.ibm.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
qemu-devel <qemu-devel@nongnu.org>, Khoa Huynh <khoa@us.ibm.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Asias He <asias@redhat.com>
Subject: Re: [Qemu-devel] [PATCH 1/7] raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane
Date: Fri, 16 Nov 2012 09:22:39 +0100 [thread overview]
Message-ID: <50A5F7CF.1050205@redhat.com> (raw)
In-Reply-To: <CAJSP0QVcYZG10CmOfDPs9_qu71TnT+1CCJ03+gaz2kGmu_xFcA@mail.gmail.com>
Il 16/11/2012 07:15, Stefan Hajnoczi ha scritto:
>> >
>> > So why not just make a string 'filename' property and open it directly
>> > in virtio-blk-data-plane? Then it's at least clear to the user and
>> > management tools what the device is capable of doing.
> There are some benefits to raw_get_aio_fd():
>
> 1. virtio-blk-data-plane is only a subset virtio-blk implementation,
> it still needs a regular virtio-blk-pci device (with BDS) in order to
> run. If we use a filename the user would have to specify it twice.
>
> 2. Fetching the file descriptor in this way ensures that the image
> file is format=raw.
>
> 3. virtio-blk-data-plane uses Linux AIO and raw-posix.c has checks
> which I don't want to duplicate - we can simply check s->use_aio in
> raw_get_aio_fd() to confirm that Linux AIO can be used.
Agreed. This is not vhost-blk, for which I agree that opening the file
would make more sense (so you have no BDS at all). It's just a stopgap
measure for something that should become the standard implementation.
Paolo
next prev parent reply other threads:[~2012-11-16 8:22 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-15 15:18 [Qemu-devel] [PATCH 0/7] virtio: virtio-blk data plane Stefan Hajnoczi
2012-11-15 15:19 ` [Qemu-devel] [PATCH 1/7] raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane Stefan Hajnoczi
2012-11-15 20:03 ` Anthony Liguori
2012-11-16 6:15 ` Stefan Hajnoczi
2012-11-16 8:22 ` Paolo Bonzini [this message]
2012-11-15 15:19 ` [Qemu-devel] [PATCH 2/7] configure: add CONFIG_VIRTIO_BLK_DATA_PLANE Stefan Hajnoczi
2012-11-15 15:19 ` [Qemu-devel] [PATCH 3/7] dataplane: add virtqueue vring code Stefan Hajnoczi
2012-11-15 15:37 ` Paolo Bonzini
2012-11-15 20:09 ` Anthony Liguori
2012-11-16 6:24 ` Stefan Hajnoczi
2012-11-16 7:48 ` Christian Borntraeger
2012-11-16 8:13 ` Stefan Hajnoczi
2012-11-17 16:15 ` Blue Swirl
2012-11-18 9:27 ` Stefan Hajnoczi
2012-11-15 15:19 ` [Qemu-devel] [PATCH 4/7] dataplane: add event loop Stefan Hajnoczi
2012-11-15 15:19 ` [Qemu-devel] [PATCH 5/7] dataplane: add Linux AIO request queue Stefan Hajnoczi
2012-11-15 15:19 ` [Qemu-devel] [PATCH 6/7] dataplane: add virtio-blk data plane code Stefan Hajnoczi
2012-11-15 15:19 ` [Qemu-devel] [PATCH 7/7] virtio-blk: add x-data-plane=on|off performance feature Stefan Hajnoczi
2012-11-15 18:48 ` Michael S. Tsirkin
2012-11-15 19:34 ` Khoa Huynh
2012-11-15 21:11 ` Anthony Liguori
2012-11-15 21:08 ` Anthony Liguori
2012-11-16 6:22 ` Stefan Hajnoczi
2012-11-19 10:38 ` Kevin Wolf
2012-11-19 10:51 ` Paolo Bonzini
2012-11-16 7:40 ` Paolo Bonzini
2012-11-20 9:02 ` [Qemu-devel] [PATCH 0/7] virtio: virtio-blk data plane Asias He
2012-11-20 12:21 ` Stefan Hajnoczi
2012-11-20 12:25 ` Stefan Hajnoczi
2012-11-21 5:39 ` Asias He
2012-11-21 6:42 ` Asias He
2012-11-21 6:44 ` Stefan Hajnoczi
2012-11-21 7:00 ` Asias He
2012-11-22 12:12 ` Stefan Hajnoczi
2012-11-21 5:22 ` Asias He
2012-11-22 12:16 ` Stefan Hajnoczi
2012-11-20 15:03 ` Khoa Huynh
2012-11-21 5:22 ` Asias He
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