Re: [virtio-comment] Re: [EXT] Re: [virtio-comment] Re: [PATCH] virtio-net: Add equal-sized receive buffers feature

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Nov 25, 2019 at 04:22:47PM +0800, Jason Wang wrote:
> 
> On 2019/11/25 下午4:18, Michael S. Tsirkin wrote:
> > > > > > Again I can see how we might want to disallow crazy setups with e.g. 1
> > > > > > byte per buffer. That's just abuse, no guest does that anyway. So asking
> > > > > > e.g. for a minimal buffer size sounds very reasonable.
> > > > > One question here is that, the minimal buffer size should depends on various
> > > > > factors. E.g the ring size. Consider a 256 entries ring, the minimal size
> > > > > should be 64K/256=256 ...
> > > > I guess you are right. We can make this driver programmable I guess?
> > > > Basically pass min_buf_len to the device.
> > > Then it still have the chance to program the min_buf_len to 1?
> > If it wants to - yes - presumably device won't work as well,
> > fetching all kind of extra data e.g. unnecessary descriptors.
> > 
> 
> Technically, device should still work for small packet and drop large
> packet.

I am not sure I agree. How is this different from just not being
sufficient space in the RX ring? We certainly do not want to
drop packets just because there's not enough buffers -
it's a temporary condition.


> Vhost has a bug that will stall RX in the case.

I think we want to spec this first then.

> Will post a fix.
> 
> Thanks


This publicly archived list offers a means to provide input to the
OASIS Virtual I/O Device (VIRTIO) TC.

In order to verify user consent to the Feedback License terms and
to minimize spam in the list archive, subscription is required
before posting.

Subscribe: virtio-comment-subscribe@lists.oasis-open.org
Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org
List help: virtio-comment-help@lists.oasis-open.org
List archive: https://lists.oasis-open.org/archives/virtio-comment/
Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf
List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists
Committee: https://www.oasis-open.org/committees/virtio/
Join OASIS: https://www.oasis-open.org/join/