QE tested this series of patches v11 under linux-next repo with virtio-net regression tests, everything works fine. Tested-by: Lei Yang <leiyang@xxxxxxxxxx> On Tue, Mar 18, 2025 at 8:29 AM Jason Wang <jasowang@xxxxxxxxxx> wrote: > > On Mon, Mar 17, 2025 at 6:58 PM Akihiko Odaki <akihiko.odaki@xxxxxxxxxx> wrote: > > > > virtio-net have two usage of hashes: one is RSS and another is hash > > reporting. Conventionally the hash calculation was done by the VMM. > > However, computing the hash after the queue was chosen defeats the > > purpose of RSS. > > > > Another approach is to use eBPF steering program. This approach has > > another downside: it cannot report the calculated hash due to the > > restrictive nature of eBPF. > > > > Introduce the code to compute hashes to the kernel in order to overcome > > thse challenges. > > > > An alternative solution is to extend the eBPF steering program so that it > > will be able to report to the userspace, but it is based on context > > rewrites, which is in feature freeze. We can adopt kfuncs, but they will > > not be UAPIs. We opt to ioctl to align with other relevant UAPIs (KVM > > and vhost_net). > > > > The patches for QEMU to use this new feature was submitted as RFC and > > is available at: > > https://patchew.org/QEMU/20250313-hash-v4-0-c75c494b495e@xxxxxxxxxx/ > > > > This work was presented at LPC 2024: > > https://lpc.events/event/18/contributions/1963/ > > > > V1 -> V2: > > Changed to introduce a new BPF program type. > > > > Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx> > > --- > > Changes in v11: > > - Added the missing code to free vnet_hash in patch > > "tap: Introduce virtio-net hash feature". > > - Link to v10: https://lore.kernel.org/r/20250313-rss-v10-0-3185d73a9af0@xxxxxxxxxx > > > > We only have 2 or 3 points that need to be sorted out. Let's hold on > to the iteration until we had an agreement. > > Thanks >
