From a315e022a72d95ef5f1d4e58e903cb492b0ad931 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:51 +0200 Subject: xsk: tighten UMEM headroom validation to account for tailroom and min frame MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The current headroom validation in xdp_umem_reg() could leave us with insufficient space dedicated to even receive minimum-sized ethernet frame. Furthermore if multi-buffer would come to play then skb_shared_info stored at the end of XSK frame would be corrupted. HW typically works with 128-aligned sizes so let us provide this value as bare minimum. Multi-buffer setting is known later in the configuration process so besides accounting for 128 bytes, let us also take care of tailroom space upfront. Reviewed-by: Björn Töpel Acked-by: Stanislav Fomichev Fixes: 99e3a236dd43 ("xsk: Add missing check on user supplied headroom size") Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-2-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- net/xdp/xdp_umem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 066ce07c506d..58da2f4f4397 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -203,7 +203,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr) if (!unaligned_chunks && chunks_rem) return -EINVAL; - if (headroom >= chunk_size - XDP_PACKET_HEADROOM) + if (headroom > chunk_size - XDP_PACKET_HEADROOM - + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) - 128) return -EINVAL; if (mr->flags & XDP_UMEM_TX_METADATA_LEN) { -- cgit v1.2.3 From 1ee1605138fc94cc8f8f273321dd2471c64977f9 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:52 +0200 Subject: xsk: respect tailroom for ZC setups MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Multi-buffer XDP stores information about frags in skb_shared_info that sits at the tailroom of a packet. The storage space is reserved via xdp_data_hard_end(): ((xdp)->data_hard_start + (xdp)->frame_sz - \ SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) and then we refer to it via macro below: static inline struct skb_shared_info * xdp_get_shared_info_from_buff(const struct xdp_buff *xdp) { return (struct skb_shared_info *)xdp_data_hard_end(xdp); } Currently we do not respect this tailroom space in multi-buffer AF_XDP ZC scenario. To address this, introduce xsk_pool_get_tailroom() and use it within xsk_pool_get_rx_frame_size() which is used in ZC drivers to configure length of HW Rx buffer. Typically drivers on Rx Hw buffers side work on 128 byte alignment so let us align the value returned by xsk_pool_get_rx_frame_size() in order to avoid addressing this on driver's side. This addresses the fact that idpf uses mentioned function *before* pool->dev being set so we were at risk that after subtracting tailroom we would not provide 128-byte aligned value to HW. Since xsk_pool_get_rx_frame_size() is actively used in xsk_rcv_check() and __xsk_rcv(), add a variant of this routine that will not include 128 byte alignment and therefore old behavior is preserved. Reviewed-by: Björn Töpel Acked-by: Stanislav Fomichev Fixes: 24ea50127ecf ("xsk: support mbuf on ZC RX") Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-3-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- include/net/xdp_sock_drv.h | 23 ++++++++++++++++++++++- net/xdp/xsk.c | 4 ++-- 2 files changed, 24 insertions(+), 3 deletions(-) diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h index 6b9ebae2dc95..46797645a0c2 100644 --- a/include/net/xdp_sock_drv.h +++ b/include/net/xdp_sock_drv.h @@ -41,16 +41,37 @@ static inline u32 xsk_pool_get_headroom(struct xsk_buff_pool *pool) return XDP_PACKET_HEADROOM + pool->headroom; } +static inline u32 xsk_pool_get_tailroom(bool mbuf) +{ + return mbuf ? SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) : 0; +} + static inline u32 xsk_pool_get_chunk_size(struct xsk_buff_pool *pool) { return pool->chunk_size; } -static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool) +static inline u32 __xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool) { return xsk_pool_get_chunk_size(pool) - xsk_pool_get_headroom(pool); } +static inline u32 xsk_pool_get_rx_frame_size(struct xsk_buff_pool *pool) +{ + u32 frame_size = __xsk_pool_get_rx_frame_size(pool); + struct xdp_umem *umem = pool->umem; + bool mbuf; + + /* Reserve tailroom only for zero-copy pools that opted into + * multi-buffer. The reserved area is used for skb_shared_info, + * matching the XDP core's xdp_data_hard_end() layout. + */ + mbuf = pool->dev && (umem->flags & XDP_UMEM_SG_FLAG); + frame_size -= xsk_pool_get_tailroom(mbuf); + + return ALIGN_DOWN(frame_size, 128); +} + static inline u32 xsk_pool_get_rx_frag_step(struct xsk_buff_pool *pool) { return pool->unaligned ? 0 : xsk_pool_get_chunk_size(pool); diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 6149f6a79897..c8ef9e427c9c 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -239,7 +239,7 @@ static u32 xsk_copy_xdp(void *to, void **from, u32 to_len, static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) { - u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool); + u32 frame_size = __xsk_pool_get_rx_frame_size(xs->pool); void *copy_from = xsk_copy_xdp_start(xdp), *copy_to; u32 from_len, meta_len, rem, num_desc; struct xdp_buff_xsk *xskb; @@ -338,7 +338,7 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) return -EINVAL; - if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { + if (len > __xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { xs->rx_dropped++; return -ENOSPC; } -- cgit v1.2.3 From 93e84fe45b752d17a5a46b306ed78f0133bbc719 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:53 +0200 Subject: xsk: fix XDP_UMEM_SG_FLAG issues MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently xp_assign_dev_shared() is missing XDP_USE_SG being propagated to flags so set it in order to preserve mtu check that is supposed to be done only when no multi-buffer setup is in picture. Also, this flag has the same value as XDP_UMEM_TX_SW_CSUM so we could get unexpected SG setups for software Tx checksums. Since csum flag is UAPI, modify value of XDP_UMEM_SG_FLAG. Fixes: d609f3d228a8 ("xsk: add multi-buffer support for sockets sharing umem") Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-4-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- include/net/xdp_sock.h | 2 +- net/xdp/xsk_buff_pool.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index 23e8861e8b25..ebac60a3d8a1 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -14,7 +14,7 @@ #include #include -#define XDP_UMEM_SG_FLAG (1 << 1) +#define XDP_UMEM_SG_FLAG BIT(3) struct net_device; struct xsk_queue; diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index 37b7a68b89b3..729602a3cec0 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -247,6 +247,10 @@ int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs, struct xdp_umem *umem = umem_xs->umem; flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY; + + if (umem->flags & XDP_UMEM_SG_FLAG) + flags |= XDP_USE_SG; + if (umem_xs->pool->uses_need_wakeup) flags |= XDP_USE_NEED_WAKEUP; -- cgit v1.2.3 From 36ee60b569ba0dfb6f961333b90d19ab5b323fa9 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:54 +0200 Subject: xsk: validate MTU against usable frame size on bind MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit AF_XDP bind currently accepts zero-copy pool configurations without verifying that the device MTU fits into the usable frame space provided by the UMEM chunk. This becomes a problem since we started to respect tailroom which is subtracted from chunk_size (among with headroom). 2k chunk size might not provide enough space for standard 1500 MTU, so let us catch such settings at bind time. Furthermore, validate whether underlying HW will be able to satisfy configured MTU wrt XSK's frame size multiplied by supported Rx buffer chain length (that is exposed via net_device::xdp_zc_max_segs). Fixes: 24ea50127ecf ("xsk: support mbuf on ZC RX") Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-5-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- net/xdp/xsk_buff_pool.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c index 729602a3cec0..cd7bc50872f6 100644 --- a/net/xdp/xsk_buff_pool.c +++ b/net/xdp/xsk_buff_pool.c @@ -10,6 +10,8 @@ #include "xdp_umem.h" #include "xsk.h" +#define ETH_PAD_LEN (ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN) + void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs) { if (!xs->tx) @@ -157,8 +159,12 @@ static void xp_disable_drv_zc(struct xsk_buff_pool *pool) int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *netdev, u16 queue_id, u16 flags) { + u32 needed = netdev->mtu + ETH_PAD_LEN; + u32 segs = netdev->xdp_zc_max_segs; + bool mbuf = flags & XDP_USE_SG; bool force_zc, force_copy; struct netdev_bpf bpf; + u32 frame_size; int err = 0; ASSERT_RTNL(); @@ -178,7 +184,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool, if (err) return err; - if (flags & XDP_USE_SG) + if (mbuf) pool->umem->flags |= XDP_UMEM_SG_FLAG; if (flags & XDP_USE_NEED_WAKEUP) @@ -200,8 +206,24 @@ int xp_assign_dev(struct xsk_buff_pool *pool, goto err_unreg_pool; } - if (netdev->xdp_zc_max_segs == 1 && (flags & XDP_USE_SG)) { - err = -EOPNOTSUPP; + if (mbuf) { + if (segs == 1) { + err = -EOPNOTSUPP; + goto err_unreg_pool; + } + } else { + segs = 1; + } + + /* open-code xsk_pool_get_rx_frame_size() as pool->dev is not + * set yet at this point; we are before getting down to driver + */ + frame_size = __xsk_pool_get_rx_frame_size(pool) - + xsk_pool_get_tailroom(mbuf); + frame_size = ALIGN_DOWN(frame_size, 128); + + if (needed > frame_size * segs) { + err = -EINVAL; goto err_unreg_pool; } -- cgit v1.2.3 From c5866a6be47207b05c6eead6292c8551c8a91669 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:55 +0200 Subject: selftests: bpf: introduce a common routine for reading procfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Parametrize current way of getting MAX_SKB_FRAGS value from {sys,proc}fs so that it can be re-used to get cache line size of system's CPU. All that just to mimic and compute size of kernel's struct skb_shared_info which for xsk and test suite interpret as tailroom. Introduce two variables to ifobject struct that will carry count of skb frags and tailroom size. Do the reading and computing once, at the beginning of test suite execution in xskxceiver, but for test_progs such way is not possible as in this environment each test setups and torns down ifobject structs. Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-6-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- tools/testing/selftests/bpf/prog_tests/test_xsk.c | 25 +---------------------- tools/testing/selftests/bpf/prog_tests/test_xsk.h | 23 +++++++++++++++++++++ tools/testing/selftests/bpf/prog_tests/xsk.c | 19 +++++++++++++++++ tools/testing/selftests/bpf/xskxceiver.c | 23 +++++++++++++++++++++ 4 files changed, 66 insertions(+), 24 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.c b/tools/testing/selftests/bpf/prog_tests/test_xsk.c index 7e38ec6e656b..62118ffba661 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_xsk.c +++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.c @@ -179,25 +179,6 @@ int xsk_configure_socket(struct xsk_socket_info *xsk, struct xsk_umem_info *umem return xsk_socket__create(&xsk->xsk, ifobject->ifindex, 0, umem->umem, rxr, txr, &cfg); } -#define MAX_SKB_FRAGS_PATH "/proc/sys/net/core/max_skb_frags" -static unsigned int get_max_skb_frags(void) -{ - unsigned int max_skb_frags = 0; - FILE *file; - - file = fopen(MAX_SKB_FRAGS_PATH, "r"); - if (!file) { - ksft_print_msg("Error opening %s\n", MAX_SKB_FRAGS_PATH); - return 0; - } - - if (fscanf(file, "%u", &max_skb_frags) != 1) - ksft_print_msg("Error reading %s\n", MAX_SKB_FRAGS_PATH); - - fclose(file); - return max_skb_frags; -} - static int set_ring_size(struct ifobject *ifobj) { int ret; @@ -2242,11 +2223,7 @@ int testapp_too_many_frags(struct test_spec *test) if (test->mode == TEST_MODE_ZC) { max_frags = test->ifobj_tx->xdp_zc_max_segs; } else { - max_frags = get_max_skb_frags(); - if (!max_frags) { - ksft_print_msg("Can't get MAX_SKB_FRAGS from system, using default (17)\n"); - max_frags = 17; - } + max_frags = test->ifobj_tx->max_skb_frags; max_frags += 1; } diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.h b/tools/testing/selftests/bpf/prog_tests/test_xsk.h index 8fc78a057de0..1ab8aee4ce56 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_xsk.h +++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.h @@ -31,6 +31,9 @@ #define SOCK_RECONF_CTR 10 #define USLEEP_MAX 10000 +#define MAX_SKB_FRAGS_PATH "/proc/sys/net/core/max_skb_frags" +#define SMP_CACHE_BYTES_PATH "/sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size" + extern bool opt_verbose; #define print_verbose(x...) do { if (opt_verbose) ksft_print_msg(x); } while (0) @@ -45,6 +48,24 @@ static inline u64 ceil_u64(u64 a, u64 b) return (a + b - 1) / b; } +static inline unsigned int read_procfs_val(const char *path) +{ + unsigned int read_val = 0; + FILE *file; + + file = fopen(path, "r"); + if (!file) { + ksft_print_msg("Error opening %s\n", path); + return 0; + } + + if (fscanf(file, "%u", &read_val) != 1) + ksft_print_msg("Error reading %s\n", path); + + fclose(file); + return read_val; +} + /* Simple test */ enum test_mode { TEST_MODE_SKB, @@ -115,6 +136,8 @@ struct ifobject { int mtu; u32 bind_flags; u32 xdp_zc_max_segs; + u32 umem_tailroom; + u32 max_skb_frags; bool tx_on; bool rx_on; bool use_poll; diff --git a/tools/testing/selftests/bpf/prog_tests/xsk.c b/tools/testing/selftests/bpf/prog_tests/xsk.c index dd4c35c0e428..6e2f63ee2a6c 100644 --- a/tools/testing/selftests/bpf/prog_tests/xsk.c +++ b/tools/testing/selftests/bpf/prog_tests/xsk.c @@ -62,6 +62,7 @@ int configure_ifobj(struct ifobject *tx, struct ifobject *rx) static void test_xsk(const struct test_spec *test_to_run, enum test_mode mode) { + u32 max_frags, umem_tailroom, cache_line_size; struct ifobject *ifobj_tx, *ifobj_rx; struct test_spec test; int ret; @@ -84,6 +85,24 @@ static void test_xsk(const struct test_spec *test_to_run, enum test_mode mode) ifobj_tx->set_ring.default_rx = ifobj_tx->ring.rx_pending; } + cache_line_size = read_procfs_val(SMP_CACHE_BYTES_PATH); + if (!cache_line_size) + cache_line_size = 64; + + max_frags = read_procfs_val(MAX_SKB_FRAGS_PATH); + if (!max_frags) + max_frags = 17; + + ifobj_tx->max_skb_frags = max_frags; + ifobj_rx->max_skb_frags = max_frags; + + /* 48 bytes is a part of skb_shared_info w/o frags array; + * 16 bytes is sizeof(skb_frag_t) + */ + umem_tailroom = ALIGN(48 + (max_frags * 16), cache_line_size); + ifobj_tx->umem_tailroom = umem_tailroom; + ifobj_rx->umem_tailroom = umem_tailroom; + if (!ASSERT_OK(init_iface(ifobj_rx, worker_testapp_validate_rx), "init RX")) goto delete_rx; if (!ASSERT_OK(init_iface(ifobj_tx, worker_testapp_validate_tx), "init TX")) diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c index 05b3cebc5ca9..7dad8556a722 100644 --- a/tools/testing/selftests/bpf/xskxceiver.c +++ b/tools/testing/selftests/bpf/xskxceiver.c @@ -80,6 +80,7 @@ #include #include #include +#include #include #include #include @@ -333,6 +334,7 @@ static void print_tests(void) int main(int argc, char **argv) { const size_t total_tests = ARRAY_SIZE(tests) + ARRAY_SIZE(ci_skip_tests); + u32 cache_line_size, max_frags, umem_tailroom; struct pkt_stream *rx_pkt_stream_default; struct pkt_stream *tx_pkt_stream_default; struct ifobject *ifobj_tx, *ifobj_rx; @@ -354,6 +356,27 @@ int main(int argc, char **argv) setlocale(LC_ALL, ""); + cache_line_size = read_procfs_val(SMP_CACHE_BYTES_PATH); + if (!cache_line_size) { + ksft_print_msg("Can't get SMP_CACHE_BYTES from system, using default (64)\n"); + cache_line_size = 64; + } + + max_frags = read_procfs_val(MAX_SKB_FRAGS_PATH); + if (!max_frags) { + ksft_print_msg("Can't get MAX_SKB_FRAGS from system, using default (17)\n"); + max_frags = 17; + } + ifobj_tx->max_skb_frags = max_frags; + ifobj_rx->max_skb_frags = max_frags; + + /* 48 bytes is a part of skb_shared_info w/o frags array; + * 16 bytes is sizeof(skb_frag_t) + */ + umem_tailroom = ALIGN(48 + (max_frags * 16), cache_line_size); + ifobj_tx->umem_tailroom = umem_tailroom; + ifobj_rx->umem_tailroom = umem_tailroom; + parse_command_line(ifobj_tx, ifobj_rx, argc, argv); if (opt_print_tests) { -- cgit v1.2.3 From 3197c51ce2fa00410f86f4829e4f9223553632f6 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:56 +0200 Subject: selftests: bpf: fix pkt grow tests MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Skip tail adjust tests in xskxceiver for SKB mode as it is not very friendly for it. multi-buffer case does not work as xdp_rxq_info that is registered for generic XDP does not report ::frag_size. The non-mbuf path copies packet via skb_pp_cow_data() which only accounts for headroom, leaving us with no tailroom and causing underlying XDP prog to drop packets therefore. For multi-buffer test on other modes, change the amount of bytes we use for growth, assume worst-case scenario and take care of headroom and tailroom. Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-7-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- tools/testing/selftests/bpf/prog_tests/test_xsk.c | 24 ++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.c b/tools/testing/selftests/bpf/prog_tests/test_xsk.c index 62118ffba661..ee60bcc22ee4 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_xsk.c +++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.c @@ -2528,16 +2528,34 @@ int testapp_adjust_tail_shrink_mb(struct test_spec *test) int testapp_adjust_tail_grow(struct test_spec *test) { + if (test->mode == TEST_MODE_SKB) + return TEST_SKIP; + /* Grow by 4 bytes for testing purpose */ return testapp_adjust_tail(test, 4, MIN_PKT_SIZE * 2); } int testapp_adjust_tail_grow_mb(struct test_spec *test) { + u32 grow_size; + + if (test->mode == TEST_MODE_SKB) + return TEST_SKIP; + + /* worst case scenario is when underlying setup will work on 3k + * buffers, let us account for it; given that we will use 6k as + * pkt_len, expect that it will be broken down to 2 descs each + * with 3k payload; + * + * 4k is truesize, 3k payload, 256 HR, 320 TR; + */ + grow_size = XSK_UMEM__MAX_FRAME_SIZE - + XSK_UMEM__LARGE_FRAME_SIZE - + XDP_PACKET_HEADROOM - + test->ifobj_tx->umem_tailroom; test->mtu = MAX_ETH_JUMBO_SIZE; - /* Grow by (frag_size - last_frag_Size) - 1 to stay inside the last fragment */ - return testapp_adjust_tail(test, (XSK_UMEM__MAX_FRAME_SIZE / 2) - 1, - XSK_UMEM__LARGE_FRAME_SIZE * 2); + + return testapp_adjust_tail(test, grow_size, XSK_UMEM__LARGE_FRAME_SIZE * 2); } int testapp_tx_queue_consumer(struct test_spec *test) -- cgit v1.2.3 From 16546954e117e65661109e788682891b15d4e3ce Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:57 +0200 Subject: selftests: bpf: have a separate variable for drop test MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently two different XDP programs share a static variable for different purposes (picking where to redirect on shared umem test & whether to drop a packet). This can be a problem when running full test suite - idx can be written by shared umem test and this value can cause a false behavior within XDP drop half test. Introduce a dedicated variable for drop half test so that these two don't step on each other toes. There is no real need for using __sync_fetch_and_add here as XSK tests are executed on single CPU. Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-8-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- tools/testing/selftests/bpf/progs/xsk_xdp_progs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c index 683306db8594..023d8befd4ca 100644 --- a/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c +++ b/tools/testing/selftests/bpf/progs/xsk_xdp_progs.c @@ -26,8 +26,10 @@ SEC("xdp.frags") int xsk_def_prog(struct xdp_md *xdp) SEC("xdp.frags") int xsk_xdp_drop(struct xdp_md *xdp) { + static unsigned int drop_idx; + /* Drop every other packet */ - if (idx++ % 2) + if (drop_idx++ % 2) return XDP_DROP; return bpf_redirect_map(&xsk, 0, XDP_DROP); -- cgit v1.2.3 From 62838e363e4f0753d43b2b78e9d3f6ad3c9102ec Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Thu, 2 Apr 2026 17:49:58 +0200 Subject: selftests: bpf: adjust rx_dropped xskxceiver's test to respect tailroom MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since we have changed how big user defined headroom in umem can be, change the logic in testapp_stats_rx_dropped() so we pass updated headroom validation in xdp_umem_reg() and still drop half of frames. Test works on non-mbuf setup so __xsk_pool_get_rx_frame_size() that is called on xsk_rcv_check() will not account skb_shared_info size. Taking the tailroom size into account in test being fixed is needed as xdp_umem_reg() defaults to respect it. Reviewed-by: Björn Töpel Signed-off-by: Maciej Fijalkowski Link: https://patch.msgid.link/20260402154958.562179-9-maciej.fijalkowski@intel.com Signed-off-by: Jakub Kicinski --- tools/testing/selftests/bpf/prog_tests/test_xsk.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/test_xsk.c b/tools/testing/selftests/bpf/prog_tests/test_xsk.c index ee60bcc22ee4..7950c504ed28 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_xsk.c +++ b/tools/testing/selftests/bpf/prog_tests/test_xsk.c @@ -1959,15 +1959,17 @@ int testapp_headroom(struct test_spec *test) int testapp_stats_rx_dropped(struct test_spec *test) { + u32 umem_tr = test->ifobj_tx->umem_tailroom; + if (test->mode == TEST_MODE_ZC) { ksft_print_msg("Can not run RX_DROPPED test for ZC mode\n"); return TEST_SKIP; } - if (pkt_stream_replace_half(test, MIN_PKT_SIZE * 4, 0)) + if (pkt_stream_replace_half(test, (MIN_PKT_SIZE * 3) + umem_tr, 0)) return TEST_FAILURE; test->ifobj_rx->umem->frame_headroom = test->ifobj_rx->umem->frame_size - - XDP_PACKET_HEADROOM - MIN_PKT_SIZE * 3; + XDP_PACKET_HEADROOM - (MIN_PKT_SIZE * 2) - umem_tr; if (pkt_stream_receive_half(test)) return TEST_FAILURE; test->ifobj_rx->validation_func = validate_rx_dropped; -- cgit v1.2.3