March 2025 - Linux-kselftest-mirror

[PATCH bpf-next v5 0/6] XDP metadata support for tun driver

by Marcus Wichelmann

Hi all, this v5 of the patch series is very similar to v4, but rebased onto the bpf-next/net branch instead of bpf-next/master. Because the commit c047e0e0e435 ("selftests/bpf: Optionally open a dedicated namespace to run test in it") is not yet included in this branch, I changed the xdp_context_tuntap test to manually create a namespace to run the test in. Not so successful pipeline: https://github.com/kernel-patches/bpf/actions/runs/13682405154 The CI pipeline failed because of veristat changes in seemingly unrelated eBPF programs. I don't think this has to do with the changes from this patch series, but if it does, please let me know what I may have to do different to make the CI pass. --- v5: - rebase onto bpf-next/net - resolve rebase conflicts - change xdp_context_tuntap test to manually create and open a network namespace using netns_new v4: https://lore.kernel.org/bpf/20250227142330.1605996-1-marcus.wichelmann@hetz… - strip unrelated changes from the selftest patches - extend commit message for "selftests/bpf: refactor xdp_context_functional test and bpf program" - the NOARP flag was not effective to prevent other packets from interfering with the tests, add a filter to the XDP program instead - run xdp_context_tuntap in a separate namespace to avoid conflicts with other tests v3: https://lore.kernel.org/bpf/20250224152909.3911544-1-marcus.wichelmann@hetz… - change the condition to handle xdp_buffs without metadata support, as suggested by Willem de Bruijn <willemb(a)google.com> - add clarifying comment why that condition is needed - set NOARP flag in selftests to ensure that the kernel does not send packets on the test interfaces that may interfere with the tests v2: https://lore.kernel.org/bpf/20250217172308.3291739-1-marcus.wichelmann@hetz… - submit against bpf-next subtree - split commits and improved commit messages - remove redundant metasize check and add clarifying comment instead - use max() instead of ternary operator - add selftest for metadata support in the tun driver v1: https://lore.kernel.org/all/20250130171614.1657224-1-marcus.wichelmann@hetz… Marcus Wichelmann (6): net: tun: enable XDP metadata support net: tun: enable transfer of XDP metadata to skb selftests/bpf: move open_tuntap to network helpers selftests/bpf: refactor xdp_context_functional test and bpf program selftests/bpf: add test for XDP metadata support in tun driver selftests/bpf: fix file descriptor assertion in open_tuntap helper drivers/net/tun.c | 28 +++- tools/testing/selftests/bpf/network_helpers.c | 28 ++++ tools/testing/selftests/bpf/network_helpers.h | 3 + .../selftests/bpf/prog_tests/lwt_helpers.h | 29 ---- .../bpf/prog_tests/xdp_context_test_run.c | 145 +++++++++++++++++- .../selftests/bpf/progs/test_xdp_meta.c | 53 +++++-- 6 files changed, 230 insertions(+), 56 deletions(-) -- 2.43.0

16 hours, 21 minutes

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[RFC PATCH 0/5] KVM: guest_memfd: support for uffd missing

by Nikita Kalyazin

This series is built on top of the v3 write syscall support [1]. With James's KVM userfault [2], it is possible to handle stage-2 faults in guest_memfd in userspace. However, KVM itself also triggers faults in guest_memfd in some cases, for example: PV interfaces like kvmclock, PV EOI and page table walking code when fetching the MMIO instruction on x86. It was agreed in the guest_memfd upstream call on 23 Jan 2025 [3] that KVM would be accessing those pages via userspace page tables. In order for such faults to be handled in userspace, guest_memfd needs to support userfaultfd. This series proposes a limited support for userfaultfd in guest_memfd: - userfaultfd support is conditional to `CONFIG_KVM_GMEM_SHARED_MEM` (as is fault support in general) - Only `page missing` event is currently supported - Userspace is supposed to respond to the event with the `write` syscall followed by `UFFDIO_CONTINUE` ioctl to unblock the faulting process. Note that we can't use `UFFDIO_COPY` here because userfaulfd code does not know how to prepare guest_memfd pages, eg remove them from direct map [4]. Not included in this series: - Proper interface for userfaultfd to recognise guest_memfd mappings - Proper handling of truncation cases after locking the page Request for comments: - Is it a sensible workflow for guest_memfd to resolve a userfault `page missing` event with `write` syscall + `UFFDIO_CONTINUE`? One of the alternatives is teaching `UFFDIO_COPY` how to deal with guest_memfd pages. - What is a way forward to make userfaultfd code aware of guest_memfd? I saw that Patrick hit a somewhat similar problem in [5] when trying to use direct map manipulation functions in KVM and was pointed by David at Elliot's guestmem library [6] that might include a shim for that. Would the library be the right place to expose required interfaces like `vma_is_gmem`? Nikita [1] https://lore.kernel.org/kvm/20250303130838.28812-1-kalyazin@amazon.com/T/ [2] https://lore.kernel.org/kvm/20250109204929.1106563-1-jthoughton@google.com/… [3] https://docs.google.com/document/d/1M6766BzdY1Lhk7LiR5IqVR8B8mG3cr-cxTxOrAo… [4] https://lore.kernel.org/kvm/20250221160728.1584559-1-roypat@amazon.co.uk/T/ [4] https://lore.kernel.org/kvm/20250221160728.1584559-1-roypat@amazon.co.uk/T/… [5] https://lore.kernel.org/kvm/20241122-guestmem-library-v5-2-450e92951a15@qui… Nikita Kalyazin (5): KVM: guest_memfd: add kvm_gmem_vma_is_gmem KVM: guest_memfd: add support for uffd missing mm: userfaultfd: allow to register userfaultfd for guest_memfd mm: userfaultfd: support continue for guest_memfd KVM: selftests: add uffd missing test for guest_memfd include/linux/userfaultfd_k.h | 9 ++ mm/userfaultfd.c | 23 ++++- .../testing/selftests/kvm/guest_memfd_test.c | 88 +++++++++++++++++++ virt/kvm/guest_memfd.c | 17 +++- virt/kvm/kvm_mm.h | 1 + 5 files changed, 136 insertions(+), 2 deletions(-) base-commit: 592e7531753dc4b711f96cd1daf808fd493d3223 -- 2.47.1

17 hours, 26 minutes

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[PATCH 0/2] kselftest/arm64: mte: Minor fixes to the MTE hugetlb test

by Catalin Marinas

The first patch makes use of the correct terminology for synchronous and asynchronous errors. The second patch checks whether PROT_MTE is supported on hugetlb mappings before continuing with the tests. Such support was added in 6.13 but people tend to use current kselftests on older kernels. Avoid the failure reporting on such kernels, just skip the tests. Catalin Marinas (2): kselftest/arm64: mte: Use the correct naming for tag check modes in check_hugetlb_options.c kselftest/arm64: mte: Skip the hugetlb tests if MTE not supported on such mappings .../arm64/mte/check_hugetlb_options.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)

18 hours, 27 minutes

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[PATCH v4 0/6] Fix some issues related to an interrupt type in pci_endpoint_test

by Kunihiko Hayashi

This series solves some issues about global "irq_type" that is used for indicating the current type for users. In addition, avoid an unexpected warning that occur due to interrupts remaining after displaying an error caused by devm_request_irq(). Patch 1 includes adding GET_IRQTYPE test (check for failure). Patch 2-4 include fixes for stable kernels that have global "irq_type". Patch 5-6 include improvements for the latest. Changes since v3: - Add GET_IRQTYPE check to pci_endpoint test in selftests - Add the reason why global variables aren't necessary (patch 5/6) - Add Reviewed-by: lines (patch {2, 4, 6}/6) Changes since v2: - Rebase to v6.14-rc1 - Update message to clarify, and add result of call trace (patch 1/5) - Add Reviewed-by: lines (patch 2/5) - Add new patch to remove global "irq_type" variable (patch 4/5) - Add new patch to replace "devm" version of IRQ functions (patch 5/5) Changes since v1: - Divide original patch into two - Add an error message example - Add "pcitest" display example - Add a patch to fix an interrupt remaining issue Kunihiko Hayashi (6): selftests: pci_endpoint: Add GET_IRQTYPE checks to each interrupt test misc: pci_endpoint_test: Avoid issue of interrupts remaining after request_irq error misc: pci_endpoint_test: Fix displaying irq_type after request_irq error misc: pci_endpoint_test: Fix irq_type to convey the correct type misc: pci_endpoint_test: Remove global 'irq_type' and 'no_msi' misc: pci_endpoint_test: Do not use managed irq functions drivers/misc/pci_endpoint_test.c | 31 +++++++------------ .../pci_endpoint/pci_endpoint_test.c | 11 ++++++- 2 files changed, 21 insertions(+), 21 deletions(-) -- 2.25.1

19 hours, 37 minutes

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[PATCH v2 0/2] Fix xdp_adjust_frags_tail_grow selftest on powerpc

by Saket Kumar Bhaskar

For platforms on powerpc architecture with a default page size greater than 4096, there was an inconsistency in fragment size calculation. This caused the BPF selftest xdp_adjust_tail/xdp_adjust_frags_tail_grow to fail on powerpc. The issue occurred because the fragment buffer size in bpf_prog_test_run_xdp() was set to 4096, while the actual data size in the fragment within the shared skb was checked against PAGE_SIZE (65536 on powerpc) in min_t, causing it to exceed 4096 and be set accordingly. This discrepancy led to an overflow when bpf_xdp_frags_increase_tail() checked for tailroom, as skb_frag_size(frag) could be greater than rxq->frag_size (when PAGE_SIZE > 4096). This change fixes: 1. test_run by getting the correct arch dependent PAGE_SIZE. 2. selftest by caculating tailroom and getting correct PAGE_SIZE. Changes: v1 -> v2: * Address comments from Alexander * Use dynamic page size, cacheline size and size of struct skb_shared_info to calculate parameters. * Fixed both test_run and selftest. v1: https://lore.kernel.org/all/20250122183720.1411176-1-skb99@linux.ibm.com/ Saket Kumar Bhaskar (2): bpf, test_run: Replace hardcoded page size with dynamic PAGE_SIZE in test_run selftests/bpf: Refactor xdp_adjust_tail selftest with dynamic sizing .../bpf/prog_tests/xdp_adjust_tail.c | 160 +++++++++++++----- .../bpf/progs/test_xdp_adjust_tail_grow.c | 41 +++-- 2 files changed, 149 insertions(+), 52 deletions(-) -- 2.43.5

20 hours, 41 minutes

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Re: [PATCH v8 3/4] scanf: convert self-test to KUnit

by Petr Mladek

On Sat 2025-02-15 14:52:22, Tamir Duberstein wrote: > On Sat, Feb 15, 2025 at 1:51 PM kernel test robot <lkp(a)intel.com> wrote: > > > > Hi Tamir, > > > > kernel test robot noticed the following build warnings: > > > > [auto build test WARNING on 7b7a883c7f4de1ee5040bd1c32aabaafde54d209] > > > > url: > https://github.com/intel-lab-lkp/linux/commits/Tamir-Duberstein/scanf-impli… > > base: 7b7a883c7f4de1ee5040bd1c32aabaafde54d209 > > patch link: > https://lore.kernel.org/r/20250214-scanf-kunit-convert-v8-3-5ea50f95f83c%40… > > patch subject: [PATCH v8 3/4] scanf: convert self-test to KUnit > > config: sh-randconfig-002-20250216 ( > https://download.01.org/0day-ci/archive/20250216/202502160245.KUrryBJR-lkp@… > ) > > compiler: sh4-linux-gcc (GCC) 14.2.0 > > reproduce (this is a W=1 build): ( > https://download.01.org/0day-ci/archive/20250216/202502160245.KUrryBJR-lkp@… > ) > > > > If you fix the issue in a separate patch/commit (i.e. not just a new > version of > > the same patch/commit), kindly add following tags > > | Reported-by: kernel test robot <lkp(a)intel.com> > > | Closes: > https://lore.kernel.org/oe-kbuild-all/202502160245.KUrryBJR-lkp@intel.com/ > > > > All warnings (new ones prefixed by >>): > > > > In file included from <command-line>: > > lib/tests/scanf_kunit.c: In function 'numbers_list_ll': > > >> include/linux/compiler.h:197:61: warning: function 'numbers_list_ll' > might be a candidate for 'gnu_scanf' format attribute > [-Wsuggest-attribute=format] > > I am not able to reproduce these warnings with clang 19.1.7. They also > don't obviously make sense to me. I have reproduced the problem with gcc: $> gcc --version gcc (SUSE Linux) 14.2.1 20250220 [revision 9ffecde121af883b60bbe60d00425036bc873048] $> make W=1 lib/test_scanf.ko CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CC [M] lib/test_scanf.o In file included from <command-line>: lib/test_scanf.c: In function ‘numbers_list_ll’: ./include/linux/compiler.h:197:61: warning: function ‘numbers_list_ll’ might be a candidate for ‘gnu_scanf’ format attribute [-Wsuggest-attribute=format] 197 | #define __BUILD_BUG_ON_ZERO_MSG(e, msg) ((int)sizeof(struct {_Static_assert(!(e), msg);})) | ^ [...] It seems that it is a regression introduced by the first patch of this patch set. And the fix is: diff --git a/lib/test_scanf.c b/lib/test_scanf.c index d1664e0d0138..e65b10c3dc11 100644 --- a/lib/test_scanf.c +++ b/lib/test_scanf.c @@ -27,7 +27,7 @@ static struct rnd_state rnd_state __initdata; typedef int (*check_fn)(const char *file, const int line, const void *check_data, const char *string, const char *fmt, int n_args, va_list ap); -static void __scanf(6, 0) __init +static void __scanf(6, 8) __init _test(const char *file, const int line, check_fn fn, const void *check_data, const char *string, const char *fmt, int n_args, ...) { Best Regards, Petr

1 day, 2 hours

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[PATCH 00/32] kselftest harness and nolibc compatibility

by Thomas Weißschuh

Nolibc is useful for selftests as the test programs can be very small, and compiled with just a kernel crosscompiler, without userspace support. Currently nolibc is only usable with kselftest.h, not the more convenient to use kselftest_harness.h This series provides this compatibility by adding new features to nolibc and removing the usage of problematic features from the harness. The first half of the series are changes to the harness, the second one are for nolibc. Both parts are very independent and can go through different trees. The last patch is not meant to be applied and serves as test that everything works correctly. Based on the next branch of the nolibc tree: https://web.git.kernel.org/pub/scm/linux/kernel/git/nolibc/linux-nolibc.git… Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de> --- Thomas Weißschuh (32): selftests: harness: Add harness selftest selftests: harness: Use C89 comment style selftests: harness: Ignore unused variant argument warning selftests: harness: Mark functions without prototypes static selftests: harness: Remove inline qualifier for wrappers selftests: harness: Guard includes on nolibc selftests: harness: Remove dependency on libatomic selftests: harness: Implement test timeouts through pidfd selftests: harness: Don't set setup_completed for fixtureless tests selftests: harness: Always provide "self" and "variant" selftests: harness: Move teardown conditional into test metadata selftests: harness: Add teardown callback to test metadata selftests: harness: Stop using setjmp()/longjmp() tools/nolibc: handle intmax_t/uintmax_t in printf tools/nolibc: use intmax definitions from compiler tools/nolibc: use pselect6_time64 if available tools/nolibc: use ppoll_time64 if available tools/nolibc: add tolower() and toupper() tools/nolibc: add _exit() tools/nolibc: add setpgrp() tools/nolibc: implement waitpid() in terms of waitid() Revert "selftests/nolibc: use waitid() over waitpid()" tools/nolibc: add dprintf() and vdprintf() tools/nolibc: add getopt() tools/nolibc: allow different write callbacks in printf tools/nolibc: allow limiting of printf destination size tools/nolibc: add snprintf() and friends selftests/nolibc: use snprintf() for printf tests selftests/nolibc: rename vfprintf test suite selftests/nolibc: add test for snprintf() truncation tools/nolibc: implement width padding in printf() HACK: selftests/nolibc: demonstrate usage of the kselftest harness tools/include/nolibc/Makefile | 1 + tools/include/nolibc/getopt.h | 105 ++ tools/include/nolibc/nolibc.h | 1 + tools/include/nolibc/stdint.h | 4 +- tools/include/nolibc/stdio.h | 127 +- tools/include/nolibc/string.h | 17 + tools/include/nolibc/sys.h | 102 +- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/kselftest/.gitignore | 1 + tools/testing/selftests/kselftest/Makefile | 6 + .../testing/selftests/kselftest/harness-selftest.c | 129 ++ .../selftests/kselftest/harness-selftest.expected | 62 + .../selftests/kselftest/harness-selftest.sh | 14 + tools/testing/selftests/kselftest_harness.h | 188 +-- tools/testing/selftests/nolibc/Makefile | 17 +- tools/testing/selftests/nolibc/harness-selftest.c | 1 + tools/testing/selftests/nolibc/nolibc-test.c | 1712 +------------------- tools/testing/selftests/nolibc/run-tests.sh | 2 +- 18 files changed, 639 insertions(+), 1851 deletions(-) --- base-commit: cb839e0cc881b4abd4a2e64cd06c2e313987a189 change-id: 20250130-nolibc-kselftest-harness-8b2c8cac43bf Best regards, -- Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>

1 day, 5 hours

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[PATCH rcu 00/10] Miscellaneous RCU changes for v6.15

by Boqun Feng

Hi, Please find the upcoming miscellaneous RCU changes. The changes can also be found at: git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux.git misc.2025.03.04a Regards, Boqun Paul E. McKenney (6): rcu: Split rcu_report_exp_cpu_mult() mask parameter and use for tracing rcu: Fix get_state_synchronize_rcu_full() GP-start detection rcu-tasks: Move RCU Tasks self-tests to core_initcall() rcu/nocb: Print segment lengths in show_rcu_nocb_gp_state() context_tracking: Make RCU watch ct_kernel_exit_state() warning Flush console log from kernel_power_off() Uladzislau Rezki (Sony) (3): rcutorture: Allow a negative value for nfakewriters rcu: Update TREE05.boot to test normal synchronize_rcu() rcu: Use _full() API to debug synchronize_rcu() Zilin Guan (1): rcu: Remove READ_ONCE() for rdp->gpwrap access in __note_gp_changes() include/linux/printk.h | 6 ++++ include/linux/rcupdate.h | 6 ---- include/linux/rcupdate_wait.h | 3 ++ init/main.c | 1 - kernel/context_tracking.c | 9 +++--- kernel/printk/printk.c | 4 +-- kernel/rcu/rcu.h | 2 +- kernel/rcu/rcutorture.c | 22 ++++++++++---- kernel/rcu/tasks.h | 5 +++- kernel/rcu/tree.c | 29 +++++++++++-------- kernel/rcu/tree_exp.h | 6 ++-- kernel/rcu/tree_nocb.h | 20 +++++++++---- kernel/reboot.c | 1 + .../rcutorture/configs/rcu/TREE05.boot | 6 ++++ 14 files changed, 78 insertions(+), 42 deletions(-) -- 2.48.1

1 day, 10 hours

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[PATCH rcu 00/11] Lazy Preempt changes for v6.15

by Boqun Feng

Hi, Please find the upcoming changes for CONFIG_PREEMPT_LAZY in RCU. The changes can also be found at: git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux.git lazypreempt.2025.02.24a Paul & Ankur, I put patch #7 and #8 (bug fixes in rcutorture) before patch #9 (which is the one that enables non-preemptible RCU in preemptible kernel), because I want to avoid introduce a bug in-between a series, appreciate it if you can double check on this. Thanks! Regards, Boqun Ankur Arora (7): rcu: fix header guard for rcu_all_qs() rcu: rename PREEMPT_AUTO to PREEMPT_LAZY sched: update __cond_resched comment about RCU quiescent states rcu: handle unstable rdp in rcu_read_unlock_strict() rcu: handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y osnoise: provide quiescent states rcu: limit PREEMPT_RCU configurations Boqun Feng (1): rcutorture: Update ->extendables check for lazy preemption Paul E. McKenney (3): rcutorture: Update rcutorture_one_extend_check() for lazy preemption rcutorture: Make scenario TREE10 build CONFIG_PREEMPT_LAZY=y rcutorture: Make scenario TREE07 build CONFIG_PREEMPT_LAZY=y include/linux/rcupdate.h | 2 +- include/linux/rcutree.h | 2 +- include/linux/srcutiny.h | 2 +- kernel/rcu/Kconfig | 4 +-- kernel/rcu/rcutorture.c | 26 ++++++++++++--- kernel/rcu/srcutiny.c | 14 ++++---- kernel/rcu/tree_plugin.h | 22 ++++++++++--- kernel/sched/core.c | 4 ++- kernel/trace/trace_osnoise.c | 32 +++++++++---------- .../selftests/rcutorture/configs/rcu/TREE07 | 3 +- .../selftests/rcutorture/configs/rcu/TREE10 | 3 +- 11 files changed, 73 insertions(+), 41 deletions(-) -- 2.39.5 (Apple Git-154)

1 day, 11 hours

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[PATCH net-next v6 0/8] Device memory TCP TX

by Mina Almasry

v6: https://lore.kernel.org/netdev/20250222191517.743530-1-almasrymina@google.c… === 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@google.c… === 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@google.… === 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@google.… [2] https://lore.kernel.org/netdev/20240913150913.1280238-2-sdf@fomichev.me/T/#… Cc: sdf(a)fomichev.me Cc: asml.silence(a)gmail.com Cc: dw(a)davidwei.uk Cc: Jamal Hadi Salim <jhs(a)mojatatu.com> Cc: Victor Nogueira <victor(a)mojatatu.com> Cc: Pedro Tammela <pctammela(a)mojatatu.com> Cc: Samiullah Khawaja <skhawaja(a)google.com> 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

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