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From: Stefan Hajnoczi <stefanha@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>,
	Anthony Liguori <aliguori@us.ibm.com>,
	qemu-devel@nongnu.org, Blue Swirl <blauwirbel@gmail.com>,
	khoa@us.ibm.com, Paolo Bonzini <pbonzini@redhat.com>,
	asias@redhat.com
Subject: Re: [Qemu-devel] [PATCH v5 04/11] dataplane: add virtqueue vring code
Date: Thu, 6 Dec 2012 13:53:41 +0100	[thread overview]
Message-ID: <20121206125341.GB2241@stefanha-thinkpad.muc.redhat.com> (raw)
In-Reply-To: <20121206112229.GK10837@redhat.com>

On Thu, Dec 06, 2012 at 01:22:29PM +0200, Michael S. Tsirkin wrote:
> On Wed, Dec 05, 2012 at 09:47:03PM +0100, Stefan Hajnoczi wrote:
> > The virtio-blk-data-plane cannot access memory using the usual QEMU
> > functions since it executes outside the global mutex and the memory APIs
> > are this time are not thread-safe.
> > 
> > This patch introduces a virtqueue module based on the kernel's vhost
> > vring code.  The trick is that we map guest memory ahead of time and
> > access it cheaply outside the global mutex.
> 
> Question: can virtio.c be reworked to use vring.c instead?
> The cost of keeping an extra memory listener around seems negligeable.
> The only issue I see is around dirty tracking for used ring writes.
> Maybe we could add a callback for this?

virtio.c and dataplane/vring.c will be unified but I think it's beyond
the scope of this series.  This is the thread-safe memory API
refactoring we discussed.

Stefan

  reply	other threads:[~2012-12-06 12:54 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-05 20:46 [Qemu-devel] [PATCH v5 00/11] virtio: virtio-blk data plane Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 01/11] raw-posix: add raw_get_aio_fd() for virtio-blk-data-plane Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 02/11] configure: add CONFIG_VIRTIO_BLK_DATA_PLANE Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 03/11] dataplane: add host memory mapping code Stefan Hajnoczi
2012-12-09  4:02   ` liu ping fan
2012-12-09 10:36     ` Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 04/11] dataplane: add virtqueue vring code Stefan Hajnoczi
2012-12-06 11:22   ` Michael S. Tsirkin
2012-12-06 12:53     ` Stefan Hajnoczi [this message]
2012-12-07 14:07   ` Kevin Wolf
2012-12-07 14:46     ` Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 05/11] dataplane: add event loop Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 06/11] dataplane: add Linux AIO request queue Stefan Hajnoczi
2012-12-07 14:21   ` Kevin Wolf
2012-12-10 13:05     ` Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 07/11] iov: add iov_discard() to remove data Stefan Hajnoczi
2012-12-06 11:36   ` Michael S. Tsirkin
2012-12-06 14:07     ` Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 08/11] test-iov: add iov_discard() testcase Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 09/11] iov: add qemu_iovec_concat_iov() Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 10/11] dataplane: add virtio-blk data plane code Stefan Hajnoczi
2012-12-06  7:35   ` Paolo Bonzini
2012-12-06 14:03     ` Stefan Hajnoczi
2012-12-07  6:06     ` Stefan Hajnoczi
2012-12-07 10:51       ` Paolo Bonzini
2012-12-06 11:33   ` Michael S. Tsirkin
2012-12-07  5:43     ` Stefan Hajnoczi
2012-12-07 18:04   ` Kevin Wolf
2012-12-10 13:06     ` Stefan Hajnoczi
2012-12-05 20:47 ` [Qemu-devel] [PATCH v5 11/11] virtio-blk: add x-data-plane=on|off performance feature Stefan Hajnoczi
2012-12-06 11:38 ` [Qemu-devel] [PATCH v5 00/11] virtio: virtio-blk data plane Michael S. Tsirkin
2012-12-07  6:12   ` Stefan Hajnoczi
2012-12-07  2:43 ` Liu Yuan
2012-12-07  5:46   ` Stefan Hajnoczi

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