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GET /api/patches/1042124/?format=api
HTTP 200 OK
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Content-Type: application/json
Vary: Accept

{
    "id": 1042124,
    "url": "http://patchwork.ozlabs.org/api/patches/1042124/?format=api",
    "web_url": "http://patchwork.ozlabs.org/project/intel-wired-lan/patch/20190214130302.29434-1-bjorn.topel@gmail.com/",
    "project": {
        "id": 46,
        "url": "http://patchwork.ozlabs.org/api/projects/46/?format=api",
        "name": "Intel Wired Ethernet development",
        "link_name": "intel-wired-lan",
        "list_id": "intel-wired-lan.osuosl.org",
        "list_email": "intel-wired-lan@osuosl.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": "",
        "list_archive_url": "",
        "list_archive_url_format": "",
        "commit_url_format": ""
    },
    "msgid": "<20190214130302.29434-1-bjorn.topel@gmail.com>",
    "list_archive_url": null,
    "date": "2019-02-14T13:03:02",
    "name": "[net] i40e: fix XDP_REDIRECT/XDP xmit ring cleanup race",
    "commit_ref": null,
    "pull_url": null,
    "state": "accepted",
    "archived": false,
    "hash": "12754fca93d4706abf58012fae583b6b123b67f9",
    "submitter": {
        "id": 70569,
        "url": "http://patchwork.ozlabs.org/api/people/70569/?format=api",
        "name": "Björn Töpel",
        "email": "bjorn.topel@gmail.com"
    },
    "delegate": {
        "id": 68,
        "url": "http://patchwork.ozlabs.org/api/users/68/?format=api",
        "username": "jtkirshe",
        "first_name": "Jeff",
        "last_name": "Kirsher",
        "email": "jeffrey.t.kirsher@intel.com"
    },
    "mbox": "http://patchwork.ozlabs.org/project/intel-wired-lan/patch/20190214130302.29434-1-bjorn.topel@gmail.com/mbox/",
    "series": [
        {
            "id": 91991,
            "url": "http://patchwork.ozlabs.org/api/series/91991/?format=api",
            "web_url": "http://patchwork.ozlabs.org/project/intel-wired-lan/list/?series=91991",
            "date": "2019-02-14T13:03:02",
            "name": "[net] i40e: fix XDP_REDIRECT/XDP xmit ring cleanup race",
            "version": 1,
            "mbox": "http://patchwork.ozlabs.org/series/91991/mbox/"
        }
    ],
    "comments": "http://patchwork.ozlabs.org/api/patches/1042124/comments/",
    "check": "pending",
    "checks": "http://patchwork.ozlabs.org/api/patches/1042124/checks/",
    "tags": {},
    "related": [],
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        "From": "=?utf-8?b?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@gmail.com>",
        "To": "intel-wired-lan@lists.osuosl.org",
        "Date": "Thu, 14 Feb 2019 14:03:02 +0100",
        "Message-Id": "<20190214130302.29434-1-bjorn.topel@gmail.com>",
        "X-Mailer": "git-send-email 2.19.1",
        "MIME-Version": "1.0",
        "Subject": "[Intel-wired-lan] [PATCH net] i40e: fix XDP_REDIRECT/XDP xmit ring\n\tcleanup race",
        "X-BeenThere": "intel-wired-lan@osuosl.org",
        "X-Mailman-Version": "2.1.29",
        "Precedence": "list",
        "List-Id": "Intel Wired Ethernet Linux Kernel Driver Development\n\t<intel-wired-lan.osuosl.org>",
        "List-Unsubscribe": "<https://lists.osuosl.org/mailman/options/intel-wired-lan>, \n\t<mailto:intel-wired-lan-request@osuosl.org?subject=unsubscribe>",
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        "Cc": "maciej.fijalkowski@intel.com, netdev@vger.kernel.org, brouer@redhat.com, \n\t=?utf-8?b?QmrDtnJuIFTDtnBlbA==?= <bjorn.topel@intel.com>,\n\tmagnus.karlsson@intel.com",
        "Content-Type": "text/plain; charset=\"utf-8\"",
        "Content-Transfer-Encoding": "base64",
        "Errors-To": "intel-wired-lan-bounces@osuosl.org",
        "Sender": "\"Intel-wired-lan\" <intel-wired-lan-bounces@osuosl.org>"
    },
    "content": "From: Björn Töpel <bjorn.topel@intel.com>\n\nWhen the driver clears the XDP xmit ring due to re-configuration or\nteardown, in-progress ndo_xdp_xmit must be taken into consideration.\n\nThe ndo_xdp_xmit function is typically called from a napi context that\nthe driver does not control. Therefore, we must be careful not to\nclear the XDP ring, while the call is on-going. This patch adds a\nsynchronize_rcu() to wait for napi(s) (preempt-disable regions and\nsoftirqs), prior clearing the queue. Further, the __I40E_CONFIG_BUSY\nflag is checked in the ndo_xdp_xmit implementation to avoid touching\nthe XDP xmit queue during re-configuration.\n\nFixes: d9314c474d4f (\"i40e: add support for XDP_REDIRECT\")\nFixes: 123cecd427b6 (\"i40e: added queue pair disable/enable functions\")\nReported-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>\nSigned-off-by: Björn Töpel <bjorn.topel@intel.com>\n---\n drivers/net/ethernet/intel/i40e/i40e_main.c | 14 ++++++++++++--\n drivers/net/ethernet/intel/i40e/i40e_txrx.c |  4 +++-\n 2 files changed, 15 insertions(+), 3 deletions(-)",
    "diff": "diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c\nindex f52e2c46e6a7..6a54a1e2f4ae 100644\n--- a/drivers/net/ethernet/intel/i40e/i40e_main.c\n+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c\n@@ -6725,8 +6725,13 @@ void i40e_down(struct i40e_vsi *vsi)\n \n \tfor (i = 0; i < vsi->num_queue_pairs; i++) {\n \t\ti40e_clean_tx_ring(vsi->tx_rings[i]);\n-\t\tif (i40e_enabled_xdp_vsi(vsi))\n+\t\tif (i40e_enabled_xdp_vsi(vsi)) {\n+\t\t\t/* Make sure that in-progress ndo_xdp_xmit\n+\t\t\t * calls are completed.\n+\t\t\t */\n+\t\t\tsynchronize_rcu();\n \t\t\ti40e_clean_tx_ring(vsi->xdp_rings[i]);\n+\t\t}\n \t\ti40e_clean_rx_ring(vsi->rx_rings[i]);\n \t}\n \n@@ -11955,8 +11960,13 @@ static void i40e_queue_pair_reset_stats(struct i40e_vsi *vsi, int queue_pair)\n static void i40e_queue_pair_clean_rings(struct i40e_vsi *vsi, int queue_pair)\n {\n \ti40e_clean_tx_ring(vsi->tx_rings[queue_pair]);\n-\tif (i40e_enabled_xdp_vsi(vsi))\n+\tif (i40e_enabled_xdp_vsi(vsi)) {\n+\t\t/* Make sure that in-progress ndo_xdp_xmit calls are\n+\t\t * completed.\n+\t\t */\n+\t\tsynchronize_rcu();\n \t\ti40e_clean_tx_ring(vsi->xdp_rings[queue_pair]);\n+\t}\n \ti40e_clean_rx_ring(vsi->rx_rings[queue_pair]);\n }\n \ndiff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c\nindex a7e14e98889f..6c97667d20ef 100644\n--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c\n+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c\n@@ -3709,6 +3709,7 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,\n \tstruct i40e_netdev_priv *np = netdev_priv(dev);\n \tunsigned int queue_index = smp_processor_id();\n \tstruct i40e_vsi *vsi = np->vsi;\n+\tstruct i40e_pf *pf = vsi->back;\n \tstruct i40e_ring *xdp_ring;\n \tint drops = 0;\n \tint i;\n@@ -3716,7 +3717,8 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,\n \tif (test_bit(__I40E_VSI_DOWN, vsi->state))\n \t\treturn -ENETDOWN;\n \n-\tif (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs)\n+\tif (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs ||\n+\t    test_bit(__I40E_CONFIG_BUSY, pf->state))\n \t\treturn -ENXIO;\n \n \tif (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))\n",
    "prefixes": [
        "net"
    ]
}