linux/include/net/xdp.h

710 lines
21 KiB

xdp: rss hash types representation The RSS hash type specifies what portion of packet data NIC hardware used when calculating RSS hash value. The RSS types are focused on Internet traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4 primarily TCP vs UDP, but some hardware supports SCTP. Hardware RSS types are differently encoded for each hardware NIC. Most hardware represent RSS hash type as a number. Determining L3 vs L4 often requires a mapping table as there often isn't a pattern or sorting according to ISO layer. The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that contains both BITs for the L3/L4 types, and combinations to be used by drivers for their mapping tables. The enum xdp_rss_type_bits get exposed to BPF via BTF, and it is up to the BPF-programmer to match using these defines. This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding a pointer value argument for provide the RSS hash type. Change signature for all xmo_rx_hash calls in drivers to make it compile. The RSS type implementations for each driver comes as separate patches. Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-12 21:48:40 +02:00
xsk: Introduce AF_XDP buffer allocation API In order to simplify AF_XDP zero-copy enablement for NIC driver developers, a new AF_XDP buffer allocation API is added. The implementation is based on a single core (single producer/consumer) buffer pool for the AF_XDP UMEM. A buffer is allocated using the xsk_buff_alloc() function, and returned using xsk_buff_free(). If a buffer is disassociated with the pool, e.g. when a buffer is passed to an AF_XDP socket, a buffer is said to be released. Currently, the release function is only used by the AF_XDP internals and not visible to the driver. Drivers using this API should register the XDP memory model with the new MEM_TYPE_XSK_BUFF_POOL type. The API is defined in net/xdp_sock_drv.h. The buffer type is struct xdp_buff, and follows the lifetime of regular xdp_buffs, i.e. the lifetime of an xdp_buff is restricted to a NAPI context. In other words, the API is not replacing xdp_frames. In addition to introducing the API and implementations, the AF_XDP core is migrated to use the new APIs. rfc->v1: Fixed build errors/warnings for m68k and riscv. (kbuild test robot) Added headroom/chunk size getter. (Maxim/Björn) v1->v2: Swapped SoBs. (Maxim) v2->v3: Initialize struct xdp_buff member frame_sz. (Björn) Add API to query the DMA address of a frame. (Maxim) Do DMA sync for CPU till the end of the frame to handle possible growth (frame_sz). (Maxim) Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200520192103.355233-6-bjorn.topel@gmail.com
2020-05-20 21:20:53 +02:00
xdp: rhashtable with allocator ID to pointer mapping Use the IDA infrastructure for getting a cyclic increasing ID number, that is used for keeping track of each registered allocator per RX-queue xdp_rxq_info. Instead of using the IDR infrastructure, which uses a radix tree, use a dynamic rhashtable, for creating ID to pointer lookup table, because this is faster. The problem that is being solved here is that, the xdp_rxq_info pointer (stored in xdp_buff) cannot be used directly, as the guaranteed lifetime is too short. The info is needed on a (potentially) remote CPU during DMA-TX completion time . In an xdp_frame the xdp_mem_info is stored, when it got converted from an xdp_buff, which is sufficient for the simple page refcnt based recycle schemes. For more advanced allocators there is a need to store a pointer to the registered allocator. Thus, there is a need to guard the lifetime or validity of the allocator pointer, which is done through this rhashtable ID map to pointer. The removal and validity of of the allocator and helper struct xdp_mem_allocator is guarded by RCU. The allocator will be created by the driver, and registered with xdp_rxq_info_reg_mem_model(). It is up-to debate who is responsible for freeing the allocator pointer or invoking the allocator destructor function. In any case, this must happen via RCU freeing. Use the IDA infrastructure for getting a cyclic increasing ID number, that is used for keeping track of each registered allocator per RX-queue xdp_rxq_info. V4: Per req of Jason Wang - Use xdp_rxq_info_reg_mem_model() in all drivers implementing XDP_REDIRECT, even-though it's not strictly necessary when allocator==NULL for type MEM_TYPE_PAGE_SHARED (given it's zero). V6: Per req of Alex Duyck - Introduce rhashtable_lookup() call in later patch V8: Address sparse should be static warnings (from kbuild test robot) Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 16:46:12 +02:00
xdp: Extend xdp_redirect_map with broadcast support This patch adds two flags BPF_F_BROADCAST and BPF_F_EXCLUDE_INGRESS to extend xdp_redirect_map for broadcast support. With BPF_F_BROADCAST the packet will be broadcasted to all the interfaces in the map. with BPF_F_EXCLUDE_INGRESS the ingress interface will be excluded when do broadcasting. When getting the devices in dev hash map via dev_map_hash_get_next_key(), there is a possibility that we fall back to the first key when a device was removed. This will duplicate packets on some interfaces. So just walk the whole buckets to avoid this issue. For dev array map, we also walk the whole map to find valid interfaces. Function bpf_clear_redirect_map() was removed in commit ee75aef23afe ("bpf, xdp: Restructure redirect actions"). Add it back as we need to use ri->map again. With test topology: +-------------------+ +-------------------+ | Host A (i40e 10G) | ---------- | eno1(i40e 10G) | +-------------------+ | | | Host B | +-------------------+ | | | Host C (i40e 10G) | ---------- | eno2(i40e 10G) | +-------------------+ | | | +------+ | | veth0 -- | Peer | | | veth1 -- | | | | veth2 -- | NS | | | +------+ | +-------------------+ On Host A: # pktgen/pktgen_sample03_burst_single_flow.sh -i eno1 -d $dst_ip -m $dst_mac -s 64 On Host B(Intel(R) Xeon(R) CPU E5-2690 v3 @ 2.60GHz, 128G Memory): Use xdp_redirect_map and xdp_redirect_map_multi in samples/bpf for testing. All the veth peers in the NS have a XDP_DROP program loaded. The forward_map max_entries in xdp_redirect_map_multi is modify to 4. Testing the performance impact on the regular xdp_redirect path with and without patch (to check impact of additional check for broadcast mode): 5.12 rc4 | redirect_map i40e->i40e | 2.0M | 9.7M 5.12 rc4 | redirect_map i40e->veth | 1.7M | 11.8M 5.12 rc4 + patch | redirect_map i40e->i40e | 2.0M | 9.6M 5.12 rc4 + patch | redirect_map i40e->veth | 1.7M | 11.7M Testing the performance when cloning packets with the redirect_map_multi test, using a redirect map size of 4, filled with 1-3 devices: 5.12 rc4 + patch | redirect_map multi i40e->veth (x1) | 1.7M | 11.4M 5.12 rc4 + patch | redirect_map multi i40e->veth (x2) | 1.1M | 4.3M 5.12 rc4 + patch | redirect_map multi i40e->veth (x3) | 0.8M | 2.6M Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/20210519090747.1655268-3-liuhangbin@gmail.com
2021-05-19 17:07:45 +08:00
xdp: transition into using xdp_frame for return API Changing API xdp_return_frame() to take struct xdp_frame as argument, seems like a natural choice. But there are some subtle performance details here that needs extra care, which is a deliberate choice. When de-referencing xdp_frame on a remote CPU during DMA-TX completion, result in the cache-line is change to "Shared" state. Later when the page is reused for RX, then this xdp_frame cache-line is written, which change the state to "Modified". This situation already happens (naturally) for, virtio_net, tun and cpumap as the xdp_frame pointer is the queued object. In tun and cpumap, the ptr_ring is used for efficiently transferring cache-lines (with pointers) between CPUs. Thus, the only option is to de-referencing xdp_frame. It is only the ixgbe driver that had an optimization, in which it can avoid doing the de-reference of xdp_frame. The driver already have TX-ring queue, which (in case of remote DMA-TX completion) have to be transferred between CPUs anyhow. In this data area, we stored a struct xdp_mem_info and a data pointer, which allowed us to avoid de-referencing xdp_frame. To compensate for this, a prefetchw is used for telling the cache coherency protocol about our access pattern. My benchmarks show that this prefetchw is enough to compensate the ixgbe driver. V7: Adjust for commit d9314c474d4f ("i40e: add support for XDP_REDIRECT") V8: Adjust for commit bd658dda4237 ("net/mlx5e: Separate dma base address and offset in dma_sync call") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-17 16:46:32 +02:00
xdp: rss hash types representation The RSS hash type specifies what portion of packet data NIC hardware used when calculating RSS hash value. The RSS types are focused on Internet traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4 primarily TCP vs UDP, but some hardware supports SCTP. Hardware RSS types are differently encoded for each hardware NIC. Most hardware represent RSS hash type as a number. Determining L3 vs L4 often requires a mapping table as there often isn't a pattern or sorting according to ISO layer. The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that contains both BITs for the L3/L4 types, and combinations to be used by drivers for their mapping tables. The enum xdp_rss_type_bits get exposed to BPF via BTF, and it is up to the BPF-programmer to match using these defines. This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding a pointer value argument for provide the RSS hash type. Change signature for all xmo_rx_hash calls in drivers to make it compile. The RSS type implementations for each driver comes as separate patches. Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-12 21:48:40 +02:00
xdp: rss hash types representation The RSS hash type specifies what portion of packet data NIC hardware used when calculating RSS hash value. The RSS types are focused on Internet traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4 primarily TCP vs UDP, but some hardware supports SCTP. Hardware RSS types are differently encoded for each hardware NIC. Most hardware represent RSS hash type as a number. Determining L3 vs L4 often requires a mapping table as there often isn't a pattern or sorting according to ISO layer. The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that contains both BITs for the L3/L4 types, and combinations to be used by drivers for their mapping tables. The enum xdp_rss_type_bits get exposed to BPF via BTF, and it is up to the BPF-programmer to match using these defines. This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding a pointer value argument for provide the RSS hash type. Change signature for all xmo_rx_hash calls in drivers to make it compile. The RSS type implementations for each driver comes as separate patches. Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-12 21:48:40 +02:00
xdp: rss hash types representation The RSS hash type specifies what portion of packet data NIC hardware used when calculating RSS hash value. The RSS types are focused on Internet traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4 primarily TCP vs UDP, but some hardware supports SCTP. Hardware RSS types are differently encoded for each hardware NIC. Most hardware represent RSS hash type as a number. Determining L3 vs L4 often requires a mapping table as there often isn't a pattern or sorting according to ISO layer. The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that contains both BITs for the L3/L4 types, and combinations to be used by drivers for their mapping tables. The enum xdp_rss_type_bits get exposed to BPF via BTF, and it is up to the BPF-programmer to match using these defines. This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding a pointer value argument for provide the RSS hash type. Change signature for all xmo_rx_hash calls in drivers to make it compile. The RSS type implementations for each driver comes as separate patches. Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-12 21:48:40 +02:00
xdp: rss hash types representation The RSS hash type specifies what portion of packet data NIC hardware used when calculating RSS hash value. The RSS types are focused on Internet traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4 primarily TCP vs UDP, but some hardware supports SCTP. Hardware RSS types are differently encoded for each hardware NIC. Most hardware represent RSS hash type as a number. Determining L3 vs L4 often requires a mapping table as there often isn't a pattern or sorting according to ISO layer. The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that contains both BITs for the L3/L4 types, and combinations to be used by drivers for their mapping tables. The enum xdp_rss_type_bits get exposed to BPF via BTF, and it is up to the BPF-programmer to match using these defines. This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding a pointer value argument for provide the RSS hash type. Change signature for all xmo_rx_hash calls in drivers to make it compile. The RSS type implementations for each driver comes as separate patches. Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-12 21:48:40 +02:00
drivers: net: turn on XDP features A summary of the flags being set for various drivers is given below. Note that XDP_F_REDIRECT_TARGET and XDP_F_FRAG_TARGET are features that can be turned off and on at runtime. This means that these flags may be set and unset under RTNL lock protection by the driver. Hence, READ_ONCE must be used by code loading the flag value. Also, these flags are not used for synchronization against the availability of XDP resources on a device. It is merely a hint, and hence the read may race with the actual teardown of XDP resources on the device. This may change in the future, e.g. operations taking a reference on the XDP resources of the driver, and in turn inhibiting turning off this flag. However, for now, it can only be used as a hint to check whether device supports becoming a redirection target. Turn 'hw-offload' feature flag on for: - netronome (nfp) - netdevsim. Turn 'native' and 'zerocopy' features flags on for: - intel (i40e, ice, ixgbe, igc) - mellanox (mlx5). - stmmac - netronome (nfp) Turn 'native' features flags on for: - amazon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2, enetc) - funeth - intel (igb) - marvell (mvneta, mvpp2, octeontx2) - mellanox (mlx4) - mtk_eth_soc - qlogic (qede) - sfc - socionext (netsec) - ti (cpsw) - tap - tsnep - veth - xen - virtio_net. Turn 'basic' (tx, pass, aborted and drop) features flags on for: - netronome (nfp) - cavium (thunder) - hyperv. Turn 'redirect_target' feature flag on for: - amanzon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2) - intel (i40e, ice, igb, ixgbe) - ti (cpsw) - marvell (mvneta, mvpp2) - sfc - socionext (netsec) - qlogic (qede) - mellanox (mlx5) - tap - veth - virtio_net - xen Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Stanislav Fomichev <sdf@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Marek Majtyka <alardam@gmail.com> Link: https://lore.kernel.org/r/3eca9fafb308462f7edb1f58e451d59209aa07eb.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-01 11:24:18 +01:00
xdp: create locked/unlocked instances of xdp redirect target setters Commit 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") introduces the netdev lock to xdp_set_features_flag(). The change includes a _locked version of the method, as it is possible for a driver to have already acquired the netdev lock before calling this helper. However, the same applies to xdp_features_(set|clear)_redirect_flags(), which ends up calling the unlocked version of xdp_set_features_flags() leading to deadlocks in GVE, which grabs the netdev lock as part of its suspend, reset, and shutdown processes: [ 833.265543] WARNING: possible recursive locking detected [ 833.270949] 6.15.0-rc1 #6 Tainted: G E [ 833.276271] -------------------------------------------- [ 833.281681] systemd-shutdow/1 is trying to acquire lock: [ 833.287090] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: xdp_set_features_flag+0x29/0x90 [ 833.295470] [ 833.295470] but task is already holding lock: [ 833.301400] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve] [ 833.309508] [ 833.309508] other info that might help us debug this: [ 833.316130] Possible unsafe locking scenario: [ 833.316130] [ 833.322142] CPU0 [ 833.324681] ---- [ 833.327220] lock(&dev->lock); [ 833.330455] lock(&dev->lock); [ 833.333689] [ 833.333689] *** DEADLOCK *** [ 833.333689] [ 833.339701] May be due to missing lock nesting notation [ 833.339701] [ 833.346582] 5 locks held by systemd-shutdow/1: [ 833.351205] #0: ffffffffa9c89130 (system_transition_mutex){+.+.}-{4:4}, at: __se_sys_reboot+0xe6/0x210 [ 833.360695] #1: ffff93b399e5c1b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xb4/0x1f0 [ 833.369144] #2: ffff949d19a471b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xc2/0x1f0 [ 833.377603] #3: ffffffffa9eca050 (rtnl_mutex){+.+.}-{4:4}, at: gve_shutdown+0x33/0x90 [gve] [ 833.386138] #4: ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve] Introduce xdp_features_(set|clear)_redirect_target_locked() versions which assume that the netdev lock has already been acquired before setting the XDP feature flag and update GVE to use the locked version. Fixes: 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") Tested-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com> Signed-off-by: Joshua Washington <joshwash@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20250422011643.3509287-1-joshwash@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-21 18:16:32 -07:00
drivers: net: turn on XDP features A summary of the flags being set for various drivers is given below. Note that XDP_F_REDIRECT_TARGET and XDP_F_FRAG_TARGET are features that can be turned off and on at runtime. This means that these flags may be set and unset under RTNL lock protection by the driver. Hence, READ_ONCE must be used by code loading the flag value. Also, these flags are not used for synchronization against the availability of XDP resources on a device. It is merely a hint, and hence the read may race with the actual teardown of XDP resources on the device. This may change in the future, e.g. operations taking a reference on the XDP resources of the driver, and in turn inhibiting turning off this flag. However, for now, it can only be used as a hint to check whether device supports becoming a redirection target. Turn 'hw-offload' feature flag on for: - netronome (nfp) - netdevsim. Turn 'native' and 'zerocopy' features flags on for: - intel (i40e, ice, ixgbe, igc) - mellanox (mlx5). - stmmac - netronome (nfp) Turn 'native' features flags on for: - amazon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2, enetc) - funeth - intel (igb) - marvell (mvneta, mvpp2, octeontx2) - mellanox (mlx4) - mtk_eth_soc - qlogic (qede) - sfc - socionext (netsec) - ti (cpsw) - tap - tsnep - veth - xen - virtio_net. Turn 'basic' (tx, pass, aborted and drop) features flags on for: - netronome (nfp) - cavium (thunder) - hyperv. Turn 'redirect_target' feature flag on for: - amanzon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2) - intel (i40e, ice, igb, ixgbe) - ti (cpsw) - marvell (mvneta, mvpp2) - sfc - socionext (netsec) - qlogic (qede) - mellanox (mlx5) - tap - veth - virtio_net - xen Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Stanislav Fomichev <sdf@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Marek Majtyka <alardam@gmail.com> Link: https://lore.kernel.org/r/3eca9fafb308462f7edb1f58e451d59209aa07eb.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-01 11:24:18 +01:00
xdp: create locked/unlocked instances of xdp redirect target setters Commit 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") introduces the netdev lock to xdp_set_features_flag(). The change includes a _locked version of the method, as it is possible for a driver to have already acquired the netdev lock before calling this helper. However, the same applies to xdp_features_(set|clear)_redirect_flags(), which ends up calling the unlocked version of xdp_set_features_flags() leading to deadlocks in GVE, which grabs the netdev lock as part of its suspend, reset, and shutdown processes: [ 833.265543] WARNING: possible recursive locking detected [ 833.270949] 6.15.0-rc1 #6 Tainted: G E [ 833.276271] -------------------------------------------- [ 833.281681] systemd-shutdow/1 is trying to acquire lock: [ 833.287090] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: xdp_set_features_flag+0x29/0x90 [ 833.295470] [ 833.295470] but task is already holding lock: [ 833.301400] ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve] [ 833.309508] [ 833.309508] other info that might help us debug this: [ 833.316130] Possible unsafe locking scenario: [ 833.316130] [ 833.322142] CPU0 [ 833.324681] ---- [ 833.327220] lock(&dev->lock); [ 833.330455] lock(&dev->lock); [ 833.333689] [ 833.333689] *** DEADLOCK *** [ 833.333689] [ 833.339701] May be due to missing lock nesting notation [ 833.339701] [ 833.346582] 5 locks held by systemd-shutdow/1: [ 833.351205] #0: ffffffffa9c89130 (system_transition_mutex){+.+.}-{4:4}, at: __se_sys_reboot+0xe6/0x210 [ 833.360695] #1: ffff93b399e5c1b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xb4/0x1f0 [ 833.369144] #2: ffff949d19a471b8 (&dev->mutex){....}-{4:4}, at: device_shutdown+0xc2/0x1f0 [ 833.377603] #3: ffffffffa9eca050 (rtnl_mutex){+.+.}-{4:4}, at: gve_shutdown+0x33/0x90 [gve] [ 833.386138] #4: ffff949d2b148c68 (&dev->lock){+.+.}-{4:4}, at: gve_shutdown+0x44/0x90 [gve] Introduce xdp_features_(set|clear)_redirect_target_locked() versions which assume that the netdev lock has already been acquired before setting the XDP feature flag and update GVE to use the locked version. Fixes: 03df156dd3a6 ("xdp: double protect netdev->xdp_flags with netdev->lock") Tested-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com> Signed-off-by: Joshua Washington <joshwash@google.com> Acked-by: Stanislav Fomichev <sdf@fomichev.me> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20250422011643.3509287-1-joshwash@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-21 18:16:32 -07:00
drivers: net: turn on XDP features A summary of the flags being set for various drivers is given below. Note that XDP_F_REDIRECT_TARGET and XDP_F_FRAG_TARGET are features that can be turned off and on at runtime. This means that these flags may be set and unset under RTNL lock protection by the driver. Hence, READ_ONCE must be used by code loading the flag value. Also, these flags are not used for synchronization against the availability of XDP resources on a device. It is merely a hint, and hence the read may race with the actual teardown of XDP resources on the device. This may change in the future, e.g. operations taking a reference on the XDP resources of the driver, and in turn inhibiting turning off this flag. However, for now, it can only be used as a hint to check whether device supports becoming a redirection target. Turn 'hw-offload' feature flag on for: - netronome (nfp) - netdevsim. Turn 'native' and 'zerocopy' features flags on for: - intel (i40e, ice, ixgbe, igc) - mellanox (mlx5). - stmmac - netronome (nfp) Turn 'native' features flags on for: - amazon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2, enetc) - funeth - intel (igb) - marvell (mvneta, mvpp2, octeontx2) - mellanox (mlx4) - mtk_eth_soc - qlogic (qede) - sfc - socionext (netsec) - ti (cpsw) - tap - tsnep - veth - xen - virtio_net. Turn 'basic' (tx, pass, aborted and drop) features flags on for: - netronome (nfp) - cavium (thunder) - hyperv. Turn 'redirect_target' feature flag on for: - amanzon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2) - intel (i40e, ice, igb, ixgbe) - ti (cpsw) - marvell (mvneta, mvpp2) - sfc - socionext (netsec) - qlogic (qede) - mellanox (mlx5) - tap - veth - virtio_net - xen Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Stanislav Fomichev <sdf@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Marek Majtyka <alardam@gmail.com> Link: https://lore.kernel.org/r/3eca9fafb308462f7edb1f58e451d59209aa07eb.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-01 11:24:18 +01:00
drivers: net: turn on XDP features A summary of the flags being set for various drivers is given below. Note that XDP_F_REDIRECT_TARGET and XDP_F_FRAG_TARGET are features that can be turned off and on at runtime. This means that these flags may be set and unset under RTNL lock protection by the driver. Hence, READ_ONCE must be used by code loading the flag value. Also, these flags are not used for synchronization against the availability of XDP resources on a device. It is merely a hint, and hence the read may race with the actual teardown of XDP resources on the device. This may change in the future, e.g. operations taking a reference on the XDP resources of the driver, and in turn inhibiting turning off this flag. However, for now, it can only be used as a hint to check whether device supports becoming a redirection target. Turn 'hw-offload' feature flag on for: - netronome (nfp) - netdevsim. Turn 'native' and 'zerocopy' features flags on for: - intel (i40e, ice, ixgbe, igc) - mellanox (mlx5). - stmmac - netronome (nfp) Turn 'native' features flags on for: - amazon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2, enetc) - funeth - intel (igb) - marvell (mvneta, mvpp2, octeontx2) - mellanox (mlx4) - mtk_eth_soc - qlogic (qede) - sfc - socionext (netsec) - ti (cpsw) - tap - tsnep - veth - xen - virtio_net. Turn 'basic' (tx, pass, aborted and drop) features flags on for: - netronome (nfp) - cavium (thunder) - hyperv. Turn 'redirect_target' feature flag on for: - amanzon (ena) - broadcom (bnxt) - freescale (dpaa, dpaa2) - intel (i40e, ice, igb, ixgbe) - ti (cpsw) - marvell (mvneta, mvpp2) - sfc - socionext (netsec) - qlogic (qede) - mellanox (mlx5) - tap - veth - virtio_net - xen Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Acked-by: Stanislav Fomichev <sdf@google.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Marek Majtyka <alardam@gmail.com> Link: https://lore.kernel.org/r/3eca9fafb308462f7edb1f58e451d59209aa07eb.1675245258.git.lorenzo@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-02-01 11:24:18 +01:00