From 4a9b32f30f805ca596d76605903a48eab58e0b88 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Tue, 29 Jan 2019 15:03:50 +0100 Subject: ixgbe: fix potential RX buffer starvation for AF_XDP When the RX rings are created they are also populated with buffers so that packets can be received. Usually these are kernel buffers, but for AF_XDP in zero-copy mode, these are user-space buffers and in this case the application might not have sent down any buffers to the driver at this point. And if no buffers are allocated at ring creation time, no packets can be received and no interrupts will be generated so the NAPI poll function that allocates buffers to the rings will never get executed. To rectify this, we kick the NAPI context of any queue with an attached AF_XDP zero-copy socket in two places in the code. Once after an XDP program has loaded and once after the umem is registered. This take care of both cases: XDP program gets loaded first then AF_XDP socket is created, and the reverse, AF_XDP socket is created first, then XDP program is loaded. Fixes: d0bcacd0a130 ("ixgbe: add AF_XDP zero-copy Rx support") Signed-off-by: Magnus Karlsson Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c') diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c index 65c3e2c979d4..654ae92342ea 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c @@ -144,11 +144,19 @@ static int ixgbe_xsk_umem_enable(struct ixgbe_adapter *adapter, ixgbe_txrx_ring_disable(adapter, qid); err = ixgbe_add_xsk_umem(adapter, umem, qid); + if (err) + return err; - if (if_running) + if (if_running) { ixgbe_txrx_ring_enable(adapter, qid); - return err; + /* Kick start the NAPI context so that receiving will start */ + err = ixgbe_xsk_async_xmit(adapter->netdev, qid); + if (err) + return err; + } + + return 0; } static int ixgbe_xsk_umem_disable(struct ixgbe_adapter *adapter, u16 qid) -- cgit v1.2.3 From c685c69fba71462c3f9f6a1fb6151cded6c74d42 Mon Sep 17 00:00:00 2001 From: Jan Sokolowski Date: Wed, 20 Feb 2019 15:20:14 +0000 Subject: ixgbe: don't do any AF_XDP zero-copy transmit if netif is not OK An issue has been found while testing zero-copy XDP that causes a reset to be triggered. As it takes some time to turn the carrier on after setting zc, and we already start trying to transmit some packets, watchdog considers this as an erroneous state and triggers a reset. Don't do any work if netif carrier is not OK. Fixes: 8221c5eba8c13 (ixgbe: add AF_XDP zero-copy Tx support) Signed-off-by: Jan Sokolowski Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c') diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c index 654ae92342ea..36a8879536a4 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c @@ -642,7 +642,8 @@ static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget) dma_addr_t dma; while (budget-- > 0) { - if (unlikely(!ixgbe_desc_unused(xdp_ring))) { + if (unlikely(!ixgbe_desc_unused(xdp_ring)) || + !netif_carrier_ok(xdp_ring->netdev)) { work_done = false; break; } -- cgit v1.2.3