I re-tested this series of patches v6 with virtio-net regression tests, everything works fine. Tested-by: Lei Yang <leiyang@xxxxxxxxxx> On Thu, Feb 27, 2025 at 12:13 PM Mina Almasry <almasrymina@xxxxxxxxxx> wrote: > > v6: https://lore.kernel.org/netdev/20250222191517.743530-1-almasrymina@xxxxxxxxxx/ > === > > v6 has no major changes. Addressed a few issues from Paolo and David, > and collected Acks from Stan. Thank you everyone for the review! > > Changes: > - retain behavior to process MSG_FASTOPEN even if the provided cmsg is > invalid (Paolo). > - Rework the freeing of tx_vec slightly (it now has its own err label). > (Paolo). > - Squash the commit that makes dmabuf unbinding scheduled work into the > same one which implements the TX path so we don't run into future > errors on bisecting (Paolo). > - Fix/add comments to explain how dmabuf binding refcounting works > (David). > > v5: https://lore.kernel.org/netdev/20250220020914.895431-1-almasrymina@xxxxxxxxxx/ > === > > v5 has no major changes; it clears up the relatively minor issues > pointed out to in v4, and rebases the series on top of net-next to > resolve the conflict with a patch that raced to the tree. It also > collects the review tags from v4. > > Changes: > - Rebase to net-next > - Fix issues in selftest (Stan). > - Address comments in the devmem and netmem driver docs (Stan and Bagas) > - Fix zerocopy_fill_skb_from_devmem return error code (Stan). > > v4: https://lore.kernel.org/netdev/20250203223916.1064540-1-almasrymina@xxxxxxxxxx/ > === > > v4 mainly addresses the critical driver support issue surfaced in v3 by > Paolo and Stan. Drivers aiming to support netmem_tx should make sure not > to pass the netmem dma-addrs to the dma-mapping APIs, as these dma-addrs > may come from dma-bufs. > > Additionally other feedback from v3 is addressed. > > Major changes: > - Add helpers to handle netmem dma-addrs. Add GVE support for > netmem_tx. > - Fix binding->tx_vec not being freed on error paths during the > tx binding. > - Add a minimal devmem_tx test to devmem.py. > - Clean up everything obsolete from the cover letter (Paolo). > > v3: https://patchwork.kernel.org/project/netdevbpf/list/?series=929401&state=* > === > > Address minor comments from RFCv2 and fix a few build warnings and > ynl-regen issues. No major changes. > > RFC v2: https://patchwork.kernel.org/project/netdevbpf/list/?series=920056&state=* > ======= > > RFC v2 addresses much of the feedback from RFC v1. I plan on sending > something close to this as net-next reopens, sending it slightly early > to get feedback if any. > > Major changes: > -------------- > > - much improved UAPI as suggested by Stan. We now interpret the iov_base > of the passed in iov from userspace as the offset into the dmabuf to > send from. This removes the need to set iov.iov_base = NULL which may > be confusing to users, and enables us to send multiple iovs in the > same sendmsg() call. ncdevmem and the docs show a sample use of that. > > - Removed the duplicate dmabuf iov_iter in binding->iov_iter. I think > this is good improvment as it was confusing to keep track of > 2 iterators for the same sendmsg, and mistracking both iterators > caused a couple of bugs reported in the last iteration that are now > resolved with this streamlining. > > - Improved test coverage in ncdevmem. Now multiple sendmsg() are tested, > and sending multiple iovs in the same sendmsg() is tested. > > - Fixed issue where dmabuf unmapping was happening in invalid context > (Stan). > > ==================================================================== > > The TX path had been dropped from the Device Memory TCP patch series > post RFCv1 [1], to make that series slightly easier to review. This > series rebases the implementation of the TX path on top of the > net_iov/netmem framework agreed upon and merged. The motivation for > the feature is thoroughly described in the docs & cover letter of the > original proposal, so I don't repeat the lengthy descriptions here, but > they are available in [1]. > > Full outline on usage of the TX path is detailed in the documentation > included with this series. > > Test example is available via the kselftest included in the series as well. > > The series is relatively small, as the TX path for this feature largely > piggybacks on the existing MSG_ZEROCOPY implementation. > > Patch Overview: > --------------- > > 1. Documentation & tests to give high level overview of the feature > being added. > > 1. Add netmem refcounting needed for the TX path. > > 2. Devmem TX netlink API. > > 3. Devmem TX net stack implementation. > > 4. Make dma-buf unbinding scheduled work to handle TX cases where it gets > freed from contexts where we can't sleep. > > 5. Add devmem TX documentation. > > 6. Add scaffolding enabling driver support for netmem_tx. Add helpers, driver > feature flag, and docs to enable drivers to declare netmem_tx support. > > 7. Guard netmem_tx against being enabled against drivers that don't > support it. > > 8. Add devmem_tx selftests. Add TX path to ncdevmem and add a test to > devmem.py. > > Testing: > -------- > > Testing is very similar to devmem TCP RX path. The ncdevmem test used > for the RX path is now augemented with client functionality to test TX > path. > > * Test Setup: > > Kernel: net-next with this RFC and memory provider API cherry-picked > locally. > > Hardware: Google Cloud A3 VMs. > > NIC: GVE with header split & RSS & flow steering support. > > Performance results are not included with this version, unfortunately. > I'm having issues running the dma-buf exporter driver against the > upstream kernel on my test setup. The issues are specific to that > dma-buf exporter and do not affect this patch series. I plan to follow > up this series with perf fixes if the tests point to issues once they're > up and running. > > Special thanks to Stan who took a stab at rebasing the TX implementation > on top of the netmem/net_iov framework merged. Parts of his proposal [2] > that are reused as-is are forked off into their own patches to give full > credit. > > [1] https://lore.kernel.org/netdev/20240909054318.1809580-1-almasrymina@xxxxxxxxxx/ > [2] https://lore.kernel.org/netdev/20240913150913.1280238-2-sdf@xxxxxxxxxxx/T/#m066dd407fbed108828e2c40ae50e3f4376ef57fd > > Cc: sdf@xxxxxxxxxxx > Cc: asml.silence@xxxxxxxxx > Cc: dw@xxxxxxxxxxx > Cc: Jamal Hadi Salim <jhs@xxxxxxxxxxxx> > Cc: Victor Nogueira <victor@xxxxxxxxxxxx> > Cc: Pedro Tammela <pctammela@xxxxxxxxxxxx> > Cc: Samiullah Khawaja <skhawaja@xxxxxxxxxx> > > > Mina Almasry (7): > net: add get_netmem/put_netmem support > net: devmem: Implement TX path > net: add devmem TCP TX documentation > net: enable driver support for netmem TX > gve: add netmem TX support to GVE DQO-RDA mode > net: check for driver support in netmem TX > selftests: ncdevmem: Implement devmem TCP TX > > Stanislav Fomichev (1): > net: devmem: TCP tx netlink api > > Documentation/netlink/specs/netdev.yaml | 12 + > Documentation/networking/devmem.rst | 150 ++++++++- > .../networking/net_cachelines/net_device.rst | 1 + > Documentation/networking/netdev-features.rst | 5 + > Documentation/networking/netmem.rst | 23 +- > drivers/net/ethernet/google/gve/gve_main.c | 4 + > drivers/net/ethernet/google/gve/gve_tx_dqo.c | 8 +- > include/linux/netdevice.h | 2 + > include/linux/skbuff.h | 17 +- > include/linux/skbuff_ref.h | 4 +- > include/net/netmem.h | 23 ++ > include/net/sock.h | 1 + > include/uapi/linux/netdev.h | 1 + > net/core/datagram.c | 48 ++- > net/core/dev.c | 3 + > net/core/devmem.c | 115 ++++++- > net/core/devmem.h | 77 ++++- > net/core/netdev-genl-gen.c | 13 + > net/core/netdev-genl-gen.h | 1 + > net/core/netdev-genl.c | 73 ++++- > net/core/skbuff.c | 48 ++- > net/core/sock.c | 6 + > net/ipv4/ip_output.c | 3 +- > net/ipv4/tcp.c | 50 ++- > net/ipv6/ip6_output.c | 3 +- > net/vmw_vsock/virtio_transport_common.c | 5 +- > tools/include/uapi/linux/netdev.h | 1 + > .../selftests/drivers/net/hw/devmem.py | 26 +- > .../selftests/drivers/net/hw/ncdevmem.c | 300 +++++++++++++++++- > 29 files changed, 950 insertions(+), 73 deletions(-) > > > base-commit: 80c4a0015ce249cf0917a04dbb3cc652a6811079 > -- > 2.48.1.658.g4767266eb4-goog > >
