From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 19 Jan 2022 04:26:42 -0500 From: "Michael S. Tsirkin" Subject: Re: [PATCH 4/5] virtio-net: add support for VIRTIO_F_ADMIN_VQ Message-ID: <20220119042012-mutt-send-email-mst@kernel.org> References: <20220113145103.26894-1-mgurtovoy@nvidia.com> <20220113145103.26894-5-mgurtovoy@nvidia.com> <20220113125409-mutt-send-email-mst@kernel.org> <38c7b7a3-e0d8-d242-8723-11cabbbcb47d@nvidia.com> <20220117171459-mutt-send-email-mst@kernel.org> <631d8512-6a28-a714-4a71-dded3ef9ce3c@redhat.com> <20220118002309-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Disposition: inline To: Jason Wang Cc: Parav Pandit , Max Gurtovoy , "virtio-comment@lists.oasis-open.org" , "cohuck@redhat.com" , "virtio-dev@lists.oasis-open.org" , Shahaf Shuler , Oren Duer , "stefanha@redhat.com" List-ID: On Wed, Jan 19, 2022 at 12:16:47PM +0800, Jason Wang wrote: > > We also need > > - something like injecting cvq commands to control rx mode from the admin device > > - page fault / dirty page handling > > > > these two seem to call for a vq. > > Right, but vq is not necessarily for PF if we had PASID. And with > PASID we don't even need a dedicated new cvq. I don't think it's a good idea to mix transactions from multiple PASIDs on the same vq. Attaching a PASID to a queue seems more reasonable. cvq is under guest control, so yes I think a separate vq is preferable. What is true is that with subfunctions you would have PASID per subfunction and then one subfunction for control. I think a sketch of how things will work with scalable iov can't hurt as part of this proposal. And, I'm not sure we should have so much flexibility: if there's an interface that works for SRIOV and SIOV then that seems preferable than having distinct transports for SRIOV and SIOV. -- MST