On 10/17/2016 03:21 PM, Yuanhan Liu wrote: > On Mon, Oct 17, 2016 at 01:23:23PM +0200, Maxime Coquelin wrote: >>> On my side, I just setup 2 Windows 2016 VMs, and confirm the issue. >>> I'll continue the investigation early next week. >> >> The root cause is identified. >> When INDIRECT_DESC feature is negotiated, Windows guest uses indirect >> for both Tx and Rx descriptors, whereas Linux guests (Virtio PMD & >> virtio-net kernel driver) use indirect only for Tx. >> I'll implement indirect support for the Rx path in vhost lib, but the >> change will be too big for -rc release. >> I propose in the mean time to disable INDIRECT_DESC feature in vhost >> lib, we can still enable it locally for testing. >> >> Yuanhan, is it ok for you? > > That's okay. I'll send a patch to disable it then.
> >> >>> Has anyone already tested Windows guest with vhost-net, which also has >>> indirect descs support? >> >> I tested and confirm it works with vhost-net. > > I'm a bit confused then. IIRC, vhost-net also doesn't support indirect > for Rx path, right? No, it does support it actually. I thought it didn't support too, I misread the Kernel implementation of vhost-net and virtio-net. Acutally, virtio-net makes use of indirect in Rx path when mergeable buffers is disabled. The confusion certainly comes from me, sorry about that. Maxime
