> > > The rest of stuff can probably just be moved to after find_vqs without > > > much pain. > > > > > Actually, I think that with a little bit of pain :) > > If we use small vrings and a GRO feature bit is set, Linux will need to > > allocate 64KB of continuous memory for every receive descriptor.. > > Oh right. Hmm. Well this is same as big packets though, isn't it? >
Well, when VIRTIO_NET_F_MRG_RXBUF is not negotiated and one of the GRO features is, the receive buffers are page size buffers chained together to form a 64K buffer. In this case, do all the chained descriptors actually point to a single block of continuous memory, or is it possible for the descriptors to point to pages spread all over? > > > Instead of failing probe if GRO/CVQ are set, can we just reset the device > > if we discover small vrings and start over? > > Can we remember that this device uses small vrings, and then just avoid > > negotiating the features that we cannot support? > > > We technically can of course. I am just not sure supporting CVQ with just 1 > s/g entry will > ever be viable. Even if we won't support 1 s/g entry, do we want to fail probe in such cases? We could just disable the CVQ feature (with reset, as suggested before). I'm not saying that we should, just raising the option. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
