On 12/03/2009 10:42 AM, Avishay Traeger1 wrote:> I previously submitted a patch to have the guest virtio-blk driver get the > value for the maximum I/O size from the host bdrv, rather than assume that > there is no limit. Avi requested that I first patch the virtio spec > (http://ozlabs.org/~rusty/virtio-spec/). Below is that patch. > > Please CC me on replies, as I am not subscribed. > >Copying Rusty and virtualization at .> Thank you, > Avishay > > Signed-off-by: Avishay Traeger<avishay at il.ibm.com> > > --- virtio-spec-0.8.2.lyx 2009-11-30 16:34:16.000000000 +0200 > +++ virtio-spec-0.8.2-mod.lyx 2009-12-01 16:04:36.000000000 +0200 > @@ -3999,6 +3999,20 @@ > \end_inset > > . > +\change_inserted 0 1259672174 > + > +\end_layout > + > +\begin_layout Description > + > +\change_inserted 0 1259672252 > +VIRTIO_BLK_F_SECTOR_MAX > +\begin_inset space ~ > +\end_inset > + > +(10) Maximum sectors in an I/O. > +\change_unchanged > + > \end_layout > > \end_deeper > @@ -4068,6 +4082,17 @@ > \begin_layout Plain Layout > > u32 blk_size; > +\change_inserted 0 1259672274 > + > +\end_layout > + > +\begin_layout Plain Layout > + > +\change_inserted 0 1259672305 > + > + u32 sectors_max; > +\change_unchanged > + > \end_layout > > \begin_layout Plain Layout > @@ -4107,6 +4132,18 @@ > \begin_layout Enumerate > If the VIRTIO_BLK_F_RO feature is set by the device, any write requests > will fail. > +\change_inserted 0 1259672345 > + > +\end_layout > + > +\begin_layout Enumerate > + > +\change_inserted 0 1259672454 > +If the VIRTIO_BLK_F_SECTOR_MAX feature is negotiated, the sectors_max > field > + should be read to determine the maximum I/O size for the driver to use. > + No requests should be submitted which go beyond this limit. > +\change_unchanged > + > \end_layout > > \begin_layout Section* > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >-- error compiling committee.c: too many arguments to function
Rusty Russell
2009-Dec-08 05:48 UTC
[PATCH] virtio spec: add virtio-blk max sectors feature
On Thu, 3 Dec 2009 08:28:38 pm Avi Kivity wrote:> On 12/03/2009 10:42 AM, Avishay Traeger1 wrote: > > I previously submitted a patch to have the guest virtio-blk driver get the > > value for the maximum I/O size from the host bdrv, rather than assume that > > there is no limit. Avi requested that I first patch the virtio spec > > (http://ozlabs.org/~rusty/virtio-spec/). Below is that patch. > > > > Please CC me on replies, as I am not subscribed. > > > > > > Copying Rusty and virtualization at .Thanks Avi... Avishay; this would be the total sectors in an I/O, as separate from SIZE_MAX (maximum size of any single scatterlist entry) and SEG_MAX (maximum number of scatterlist entries)? Seems like a reasonable idea; esp if you need it. Thanks! Rusty.
Avishay Traeger1
2009-Dec-08 09:44 UTC
[PATCH] virtio spec: add virtio-blk max sectors feature
Rusty Russell <rusty at rustcorp.com.au> wrote on 12/08/2009 07:48:00 AM:> Avishay; this would be the total sectors in an I/O, as separate fromSIZE_MAX> (maximum size of any single scatterlist entry) and SEG_MAX (maximumnumber of> scatterlist entries)?Correct. In the guest virtblk driver, it changes the call to blk_queue_max_sectors().> Seems like a reasonable idea; esp if you need it.I do.> Thanks! > Rusty.Sure. Avi - do you want me to resubmit the kvm and qemu patches? Thanks, Avishay