| Message ID | 20260224174618.2780516-3-aleksander.lobakin@intel.com |
|---|---|
| State | Under Review |
| Delegated to: | Anthony Nguyen |
| Headers | show |
| Series | ice: add support for devmem/io_uring Rx and Tx | expand |
On 2/24/2026 9:46 AM, Alexander Lobakin wrote: > libeth uses netmems for quite some time already, so in order to > support unreadable frags / memory providers, it only needs to set > PP_FLAG_ALLOW_UNREADABLE_NETMEM when needed. > Also add a couple sanity checks to make sure the driver didn't mess > up the configuration options and, in case when an MP is installed, > return the truesize always equal to PAGE_SIZE, so that > libeth_rx_alloc() will never try to allocate frags. Memory providers > manage buffers on their own and expect 1:1 buffer / HW Rx descriptor > association. > > Bonus: mention in the libeth_sqe_type description that > LIBETH_SQE_EMPTY should also be used for netmem Tx SQEs -- they > don't need DMA unmapping. > > Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> > Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> > Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> > --- > include/net/libeth/tx.h | 2 +- > drivers/net/ethernet/intel/libeth/rx.c | 42 ++++++++++++++++++++++++++ > 2 files changed, 43 insertions(+), 1 deletion(-) > > diff --git a/include/net/libeth/tx.h b/include/net/libeth/tx.h > index c3db5c6f1641..a66fc2b3a114 100644 > --- a/include/net/libeth/tx.h > +++ b/include/net/libeth/tx.h > @@ -12,7 +12,7 @@ > > /** > * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion > - * @LIBETH_SQE_EMPTY: unused/empty OR XDP_TX/XSk frame, no action required > + * @LIBETH_SQE_EMPTY: empty OR netmem/XDP_TX/XSk frame, no action required > * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required > * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree() > * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA > diff --git a/drivers/net/ethernet/intel/libeth/rx.c b/drivers/net/ethernet/intel/libeth/rx.c > index 8874b714cdcc..11e6e8f353ef 100644 > --- a/drivers/net/ethernet/intel/libeth/rx.c > +++ b/drivers/net/ethernet/intel/libeth/rx.c > @@ -6,6 +6,7 @@ > #include <linux/export.h> > > #include <net/libeth/rx.h> > +#include <net/netdev_queues.h> > > /* Rx buffer management */ > > @@ -139,9 +140,47 @@ static bool libeth_rx_page_pool_params_zc(struct libeth_fq *fq, > fq->buf_len = clamp(mtu, LIBETH_RX_BUF_STRIDE, max); > fq->truesize = fq->buf_len; > > + /* > + * Allow frags only for kernel pages. `fq->truesize == pp->max_len` > + * will always fall back to regular page_pool_alloc_netmems() > + * regardless of the MTU / FQ buffer size. > + */ > + if (pp->flags & PP_FLAG_ALLOW_UNREADABLE_NETMEM) > + fq->truesize = pp->max_len; > + > return true; > } > > +/** > + * libeth_rx_page_pool_check_unread - check input params for unreadable MPs > + * @fq: buffer queue to check > + * @pp: &page_pool_params for the queue > + * > + * Make sure we don't create an invalid pool with full-frame unreadable > + * buffers, bidirectional unreadable buffers or so, and configure the > + * ZC payload pool accordingly. > + * > + * Return: true on success, false on invalid input params. > + */ > +static bool libeth_rx_page_pool_check_unread(const struct libeth_fq *fq, > + struct page_pool_params *pp) > +{ > + if (!netif_rxq_has_unreadable_mp(pp->netdev, pp->queue_idx)) > + return true; This is causing a crash on IDPF: [ 420.570632] BUG: kernel NULL pointer dereference, address: 00000000000000e8 [ 420.570684] #PF: supervisor read access in kernel mode [ 420.570712] #PF: error_code(0x0000) - not-present page [ 420.570739] PGD 0 [ 420.570757] Oops: Oops: 0000 [#1] SMP NOPTI [ 420.570784] CPU: 35 UID: 0 PID: 1058 Comm: kworker/u258:8 Kdump: loaded Tainted: G S OE 7.0.0-rc1-next-devq-030526+ #34 PREEMPT(full) [ 420.570844] Tainted: [S]=CPU_OUT_OF_SPEC, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 420.570872] Hardware name: Intel Corporation M50CYP2SBSTD/M50CYP2SBSTD, BIOS SE5C6200.86B.0027.P10.2201070222 01/07/2022 [ 420.570912] Workqueue: idpf-0000:83:00.0-vc_event idpf_vc_event_task [idpf] [ 420.570967] RIP: 0010:netif_rxq_has_unreadable_mp+0xf/0x30 [ 420.571004] Code: 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 89 f6 48 c1 e6 08 <48> 03 b7 e8 00 00 00 48 83 be c8 00 00 00 00 0f 95 c0 e9 8a 25 2b [ 420.571078] RSP: 0018:ff6bf03aa83e7bd8 EFLAGS: 00010246 [ 420.571109] RAX: ff3579f9888ed0d0 RBX: ff6bf03aa83e7c78 RCX: 0000000000000000 [ 420.571145] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 420.571178] RBP: ff6bf03aa83e7be0 R08: 0000000000000040 R09: 000000004b1a4093 [ 420.571213] R10: 0000000000000003 R11: ff3579f9bed90ee0 R12: ff3579f9d58c6060 [ 420.571247] R13: ff6bf03aa83e7d88 R14: 0000000000000001 R15: ff3579f9d58c6050 [ 420.571281] FS: 0000000000000000(0000) GS:ff357a195e9db000(0000) knlGS:0000000000000000 [ 420.571320] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 420.571350] CR2: 00000000000000e8 CR3: 00000023b2e2a006 CR4: 0000000000773ef0 [ 420.571384] PKRU: 55555554 [ 420.571402] Call Trace: [ 420.571419] <TASK> [ 420.571436] libeth_rx_fq_create+0x7c/0x380 [libeth] [ 420.571479] libie_ctlq_init+0x304/0x460 [libie_cp] [ 420.571516] libie_ctlq_xn_init+0x29/0x230 [libie_cp] [ 420.571550] idpf_init_dflt_mbx+0xa7/0x170 [idpf] [ 420.571611] idpf_vc_event_task+0x15d/0x2f0 [idpf] [ 420.571655] process_one_work+0x226/0x730 [ 420.571699] worker_thread+0x19e/0x340 [ 420.571729] ? __pfx_worker_thread+0x10/0x10 [ 420.571760] kthread+0xf4/0x130 [ 420.571785] ? __pfx_kthread+0x10/0x10 [ 420.571813] ret_from_fork+0x32c/0x410 [ 420.571844] ? __pfx_kthread+0x10/0x10 [ 420.571871] ret_from_fork_asm+0x1a/0x30 [ 420.571909] </TASK> The driver will call idpf_init_dflt_mbx() before the netdevs are created. Thanks, Emil > + > + /* For now, the core stack doesn't allow XDP with unreadable frags */ > + if (fq->xdp) > + return false; > + > + /* It should be either a header pool or a ZC payload pool */ > + if (fq->type == LIBETH_FQE_HDR) > + return !fq->hsplit; > + > + pp->flags |= PP_FLAG_ALLOW_UNREADABLE_NETMEM; > + > + return fq->hsplit; > +} > + > /** > * libeth_rx_fq_create - create a PP with the default libeth settings > * @fq: buffer queue struct to fill > @@ -165,6 +204,9 @@ int libeth_rx_fq_create(struct libeth_fq *fq, struct napi_struct *napi) > struct page_pool *pool; > int ret; > > + if (!libeth_rx_page_pool_check_unread(fq, &pp)) > + return -EINVAL; > + > pp.dma_dir = fq->xdp ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE; > > if (!fq->hsplit)
From: Tantilov, Emil S <emil.s.tantilov@intel.com> Date: Thu, 5 Mar 2026 14:04:52 -0800 > > > On 2/24/2026 9:46 AM, Alexander Lobakin wrote: >> libeth uses netmems for quite some time already, so in order to >> support unreadable frags / memory providers, it only needs to set >> PP_FLAG_ALLOW_UNREADABLE_NETMEM when needed. >> Also add a couple sanity checks to make sure the driver didn't mess >> up the configuration options and, in case when an MP is installed, >> return the truesize always equal to PAGE_SIZE, so that >> libeth_rx_alloc() will never try to allocate frags. Memory providers >> manage buffers on their own and expect 1:1 buffer / HW Rx descriptor >> association. >> >> Bonus: mention in the libeth_sqe_type description that >> LIBETH_SQE_EMPTY should also be used for netmem Tx SQEs -- they >> don't need DMA unmapping. >> >> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> >> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> >> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> >> --- >> include/net/libeth/tx.h | 2 +- >> drivers/net/ethernet/intel/libeth/rx.c | 42 ++++++++++++++++++++++++++ >> 2 files changed, 43 insertions(+), 1 deletion(-) >> >> diff --git a/include/net/libeth/tx.h b/include/net/libeth/tx.h >> index c3db5c6f1641..a66fc2b3a114 100644 >> --- a/include/net/libeth/tx.h >> +++ b/include/net/libeth/tx.h >> @@ -12,7 +12,7 @@ >> /** >> * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion >> - * @LIBETH_SQE_EMPTY: unused/empty OR XDP_TX/XSk frame, no action >> required >> + * @LIBETH_SQE_EMPTY: empty OR netmem/XDP_TX/XSk frame, no action >> required >> * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action >> required >> * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree() >> * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA >> diff --git a/drivers/net/ethernet/intel/libeth/rx.c b/drivers/net/ >> ethernet/intel/libeth/rx.c >> index 8874b714cdcc..11e6e8f353ef 100644 >> --- a/drivers/net/ethernet/intel/libeth/rx.c >> +++ b/drivers/net/ethernet/intel/libeth/rx.c >> @@ -6,6 +6,7 @@ >> #include <linux/export.h> >> #include <net/libeth/rx.h> >> +#include <net/netdev_queues.h> >> /* Rx buffer management */ >> @@ -139,9 +140,47 @@ static bool >> libeth_rx_page_pool_params_zc(struct libeth_fq *fq, >> fq->buf_len = clamp(mtu, LIBETH_RX_BUF_STRIDE, max); >> fq->truesize = fq->buf_len; >> + /* >> + * Allow frags only for kernel pages. `fq->truesize == pp->max_len` >> + * will always fall back to regular page_pool_alloc_netmems() >> + * regardless of the MTU / FQ buffer size. >> + */ >> + if (pp->flags & PP_FLAG_ALLOW_UNREADABLE_NETMEM) >> + fq->truesize = pp->max_len; >> + >> return true; >> } >> +/** >> + * libeth_rx_page_pool_check_unread - check input params for >> unreadable MPs >> + * @fq: buffer queue to check >> + * @pp: &page_pool_params for the queue >> + * >> + * Make sure we don't create an invalid pool with full-frame unreadable >> + * buffers, bidirectional unreadable buffers or so, and configure the >> + * ZC payload pool accordingly. >> + * >> + * Return: true on success, false on invalid input params. >> + */ >> +static bool libeth_rx_page_pool_check_unread(const struct libeth_fq *fq, >> + struct page_pool_params *pp) >> +{ >> + if (!netif_rxq_has_unreadable_mp(pp->netdev, pp->queue_idx)) >> + return true; > > This is causing a crash on IDPF: > > [ 420.570632] BUG: kernel NULL pointer dereference, address: > 00000000000000e8 > [ 420.570684] #PF: supervisor read access in kernel mode > [ 420.570712] #PF: error_code(0x0000) - not-present page > [ 420.570739] PGD 0 > [ 420.570757] Oops: Oops: 0000 [#1] SMP NOPTI > [ 420.570784] CPU: 35 UID: 0 PID: 1058 Comm: kworker/u258:8 Kdump: > loaded Tainted: G S OE 7.0.0-rc1-next-devq-030526+ #34 > PREEMPT(full) > [ 420.570844] Tainted: [S]=CPU_OUT_OF_SPEC, [O]=OOT_MODULE, > [E]=UNSIGNED_MODULE > [ 420.570872] Hardware name: Intel Corporation M50CYP2SBSTD/ > M50CYP2SBSTD, BIOS SE5C6200.86B.0027.P10.2201070222 01/07/2022 > [ 420.570912] Workqueue: idpf-0000:83:00.0-vc_event idpf_vc_event_task > [idpf] > [ 420.570967] RIP: 0010:netif_rxq_has_unreadable_mp+0xf/0x30 > [ 420.571004] Code: 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 > 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 89 f6 48 c1 e6 > 08 <48> 03 b7 e8 00 00 00 48 83 be c8 00 00 00 00 0f 95 c0 e9 8a 25 2b > [ 420.571078] RSP: 0018:ff6bf03aa83e7bd8 EFLAGS: 00010246 > [ 420.571109] RAX: ff3579f9888ed0d0 RBX: ff6bf03aa83e7c78 RCX: > 0000000000000000 > [ 420.571145] RDX: 0000000000000000 RSI: 0000000000000000 RDI: > 0000000000000000 > [ 420.571178] RBP: ff6bf03aa83e7be0 R08: 0000000000000040 R09: > 000000004b1a4093 > [ 420.571213] R10: 0000000000000003 R11: ff3579f9bed90ee0 R12: > ff3579f9d58c6060 > [ 420.571247] R13: ff6bf03aa83e7d88 R14: 0000000000000001 R15: > ff3579f9d58c6050 > [ 420.571281] FS: 0000000000000000(0000) GS:ff357a195e9db000(0000) > knlGS:0000000000000000 > [ 420.571320] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 420.571350] CR2: 00000000000000e8 CR3: 00000023b2e2a006 CR4: > 0000000000773ef0 > [ 420.571384] PKRU: 55555554 > [ 420.571402] Call Trace: > [ 420.571419] <TASK> > [ 420.571436] libeth_rx_fq_create+0x7c/0x380 [libeth] > [ 420.571479] libie_ctlq_init+0x304/0x460 [libie_cp] > [ 420.571516] libie_ctlq_xn_init+0x29/0x230 [libie_cp] > [ 420.571550] idpf_init_dflt_mbx+0xa7/0x170 [idpf] > [ 420.571611] idpf_vc_event_task+0x15d/0x2f0 [idpf] > [ 420.571655] process_one_work+0x226/0x730 > [ 420.571699] worker_thread+0x19e/0x340 > [ 420.571729] ? __pfx_worker_thread+0x10/0x10 > [ 420.571760] kthread+0xf4/0x130 > [ 420.571785] ? __pfx_kthread+0x10/0x10 > [ 420.571813] ret_from_fork+0x32c/0x410 > [ 420.571844] ? __pfx_kthread+0x10/0x10 > [ 420.571871] ret_from_fork_asm+0x1a/0x30 > [ 420.571909] </TASK> > > The driver will call idpf_init_dflt_mbx() before the netdevs are created. > > Thanks, > Emil This series is based on top of the latest net-next as the PR will be sent soon. net-next doesn't have libie_ctql. For the tree which contains ixd this will look different as it introduces ability to pass a device instead of napi_struct. Once this PR is accepted, we'll rebase the next-queue to handle this. Thanks, Olek
diff --git a/include/net/libeth/tx.h b/include/net/libeth/tx.h index c3db5c6f1641..a66fc2b3a114 100644 --- a/include/net/libeth/tx.h +++ b/include/net/libeth/tx.h @@ -12,7 +12,7 @@ /** * enum libeth_sqe_type - type of &libeth_sqe to act on Tx completion - * @LIBETH_SQE_EMPTY: unused/empty OR XDP_TX/XSk frame, no action required + * @LIBETH_SQE_EMPTY: empty OR netmem/XDP_TX/XSk frame, no action required * @LIBETH_SQE_CTX: context descriptor with empty SQE, no action required * @LIBETH_SQE_SLAB: kmalloc-allocated buffer, unmap and kfree() * @LIBETH_SQE_FRAG: mapped skb frag, only unmap DMA diff --git a/drivers/net/ethernet/intel/libeth/rx.c b/drivers/net/ethernet/intel/libeth/rx.c index 8874b714cdcc..11e6e8f353ef 100644 --- a/drivers/net/ethernet/intel/libeth/rx.c +++ b/drivers/net/ethernet/intel/libeth/rx.c @@ -6,6 +6,7 @@ #include <linux/export.h> #include <net/libeth/rx.h> +#include <net/netdev_queues.h> /* Rx buffer management */ @@ -139,9 +140,47 @@ static bool libeth_rx_page_pool_params_zc(struct libeth_fq *fq, fq->buf_len = clamp(mtu, LIBETH_RX_BUF_STRIDE, max); fq->truesize = fq->buf_len; + /* + * Allow frags only for kernel pages. `fq->truesize == pp->max_len` + * will always fall back to regular page_pool_alloc_netmems() + * regardless of the MTU / FQ buffer size. + */ + if (pp->flags & PP_FLAG_ALLOW_UNREADABLE_NETMEM) + fq->truesize = pp->max_len; + return true; } +/** + * libeth_rx_page_pool_check_unread - check input params for unreadable MPs + * @fq: buffer queue to check + * @pp: &page_pool_params for the queue + * + * Make sure we don't create an invalid pool with full-frame unreadable + * buffers, bidirectional unreadable buffers or so, and configure the + * ZC payload pool accordingly. + * + * Return: true on success, false on invalid input params. + */ +static bool libeth_rx_page_pool_check_unread(const struct libeth_fq *fq, + struct page_pool_params *pp) +{ + if (!netif_rxq_has_unreadable_mp(pp->netdev, pp->queue_idx)) + return true; + + /* For now, the core stack doesn't allow XDP with unreadable frags */ + if (fq->xdp) + return false; + + /* It should be either a header pool or a ZC payload pool */ + if (fq->type == LIBETH_FQE_HDR) + return !fq->hsplit; + + pp->flags |= PP_FLAG_ALLOW_UNREADABLE_NETMEM; + + return fq->hsplit; +} + /** * libeth_rx_fq_create - create a PP with the default libeth settings * @fq: buffer queue struct to fill @@ -165,6 +204,9 @@ int libeth_rx_fq_create(struct libeth_fq *fq, struct napi_struct *napi) struct page_pool *pool; int ret; + if (!libeth_rx_page_pool_check_unread(fq, &pp)) + return -EINVAL; + pp.dma_dir = fq->xdp ? DMA_BIDIRECTIONAL : DMA_FROM_DEVICE; if (!fq->hsplit)