{"id":2198120,"url":"http://patchwork.ozlabs.org/api/1.0/patches/2198120/?format=json","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.0/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260219115530.2019498-3-vsementsov@yandex-team.ru>","date":"2026-02-19T11:55:23","name":"[v11,2/8] net/tap: move vhost initialization to tap_setup_vhost()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"3473f4c25583a0addcd4b8846f4d7efe667501e7","submitter":{"id":84116,"url":"http://patchwork.ozlabs.org/api/1.0/people/84116/?format=json","name":"Vladimir Sementsov-Ogievskiy","email":"vsementsov@yandex-team.ru"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260219115530.2019498-3-vsementsov@yandex-team.ru/mbox/","series":[{"id":492667,"url":"http://patchwork.ozlabs.org/api/1.0/series/492667/?format=json","date":"2026-02-19T11:55:27","name":"virtio-net: live-TAP local migration","version":11,"mbox":"http://patchwork.ozlabs.org/series/492667/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2198120/checks/","tags":{},"headers":{"Return-Path":"<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=yandex-team.ru header.i=@yandex-team.ru\n header.a=rsa-sha256 header.s=default header.b=uFY82wqL;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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Thu, 19 Feb 2026 06:55:40 -0500","from mail-nwsmtp-smtp-corp-main-34.sas.yp-c.yandex.net\n (mail-nwsmtp-smtp-corp-main-34.sas.yp-c.yandex.net\n [IPv6:2a02:6b8:c24:fa2:0:640:41ee:0])\n by forwardcorp1b.mail.yandex.net (Yandex) with ESMTPS id 92D5080878;\n Thu, 19 Feb 2026 14:55:36 +0300 (MSK)","from vsementsov-lin (unknown [2a02:6bf:8080:192::1:26])\n by mail-nwsmtp-smtp-corp-main-34.sas.yp-c.yandex.net (smtpcorp/Yandex) with\n ESMTPSA id VtZwpM4A6uQ0-lpbtJ6aw; Thu, 19 Feb 2026 14:55:36 +0300"],"Precedence":"bulk","X-Yandex-Fwd":"1","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru;\n s=default; t=1771502136;\n bh=fF0WU7Y5ApYR2lkAVIV/MqBLwBoq0YXSQE5sJlwnsPM=;\n h=Message-ID:Date:In-Reply-To:Cc:Subject:References:To:From;\n b=uFY82wqLwx2GK6Ar9Pt93oNYlU/mqfxZPsCqOzQSkdtch//Fmxp8H0N61Vk4LIaKJ\n 6i85djid4dg43ruC7QC2U3SZNAJ0ye4sjyObFRIUCJBtuhHN183Rgj4Ovw9EXumwgc\n lnyndiddghYqo6875DmxCBIweiUmNaenVAglhypg=","From":"Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>","To":"jasowang@redhat.com,\n\tmst@redhat.com","Cc":"thuth@redhat.com, armbru@redhat.com, eblake@redhat.com, farosas@suse.de,\n peterx@redhat.com, zhao1.liu@intel.com, wangyanan55@huawei.com,\n philmd@linaro.org, marcel.apfelbaum@gmail.com, eduardo@habkost.net,\n davydov-max@yandex-team.ru, qemu-devel@nongnu.org,\n vsementsov@yandex-team.ru, yc-core@yandex-team.ru, leiyang@redhat.com,\n raphael.s.norwitz@gmail.com, bchaney@akamai.com","Subject":"[PATCH v11 2/8] net/tap: move vhost initialization to\n tap_setup_vhost()","Date":"Thu, 19 Feb 2026 14:55:23 +0300","Message-ID":"<20260219115530.2019498-3-vsementsov@yandex-team.ru>","X-Mailer":"git-send-email 2.52.0","In-Reply-To":"<20260219115530.2019498-1-vsementsov@yandex-team.ru>","References":"<20260219115530.2019498-1-vsementsov@yandex-team.ru>","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","Received-SPF":"pass client-ip=2a02:6b8:c02:900:1:45:d181:df01;\n envelope-from=vsementsov@yandex-team.ru; helo=forwardcorp1b.mail.yandex.net","X-Spam_score_int":"-20","X-Spam_score":"-2.1","X-Spam_bar":"--","X-Spam_report":"(-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,\n DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001,\n SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","List-Id":"qemu development <qemu-devel.nongnu.org>","List-Unsubscribe":"<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>","List-Archive":"<https://lists.nongnu.org/archive/html/qemu-devel>","List-Post":"<mailto:qemu-devel@nongnu.org>","List-Help":"<mailto:qemu-devel-request@nongnu.org?subject=help>","List-Subscribe":"<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"Make a new helper function in a way it can be reused later for\nTAP fd-migration feature: we'll need to initialize vhost in a later\npoint when we doesn't have access to QAPI parameters.\n\nSigned-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>\n---\n net/tap.c | 62 ++++++++++++++++++++++++++++++++++---------------------\n 1 file changed, 38 insertions(+), 24 deletions(-)","diff":"diff --git a/net/tap.c b/net/tap.c\nindex 1245b98408..294ca61f8b 100644\n--- a/net/tap.c\n+++ b/net/tap.c\n@@ -71,6 +71,8 @@ static const int kernel_feature_bits[] = {\n typedef struct TAPState {\n     NetClientState nc;\n     int fd;\n+    int vhostfd;\n+    uint32_t vhost_busyloop_timeout;\n     char down_script[1024];\n     char down_script_arg[128];\n     uint8_t buf[NET_BUFSIZE];\n@@ -702,6 +704,38 @@ static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,\n     return fd;\n }\n \n+static bool tap_setup_vhost(TAPState *s, Error **errp)\n+{\n+    VhostNetOptions options;\n+\n+    if (s->vhostfd == -1) {\n+        return true;\n+    }\n+\n+    options.backend_type = VHOST_BACKEND_TYPE_KERNEL;\n+    options.net_backend = &s->nc;\n+    options.busyloop_timeout = s->vhost_busyloop_timeout;\n+    options.opaque = (void *)(uintptr_t)s->vhostfd;\n+    options.nvqs = 2;\n+    options.feature_bits = kernel_feature_bits;\n+    options.get_acked_features = NULL;\n+    options.save_acked_features = NULL;\n+    options.max_tx_queue_size = 0;\n+    options.is_vhost_user = false;\n+\n+    s->vhost_net = vhost_net_init(&options);\n+    if (!s->vhost_net) {\n+        error_setg(errp,\n+                   \"vhost-net requested but could not be initialized\");\n+        return false;\n+    }\n+\n+    /* vhostfd ownership is passed to s->vhost_net */\n+    s->vhostfd = -1;\n+\n+    return true;\n+}\n+\n static bool net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,\n                              const char *name,\n                              const char *ifname, const char *script,\n@@ -736,30 +770,10 @@ static bool net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,\n         }\n     }\n \n-    if (vhostfd != -1) {\n-        VhostNetOptions options;\n-\n-        options.backend_type = VHOST_BACKEND_TYPE_KERNEL;\n-        options.net_backend = &s->nc;\n-        if (tap->has_poll_us) {\n-            options.busyloop_timeout = tap->poll_us;\n-        } else {\n-            options.busyloop_timeout = 0;\n-        }\n-        options.opaque = (void *)(uintptr_t)vhostfd;\n-        options.nvqs = 2;\n-        options.feature_bits = kernel_feature_bits;\n-        options.get_acked_features = NULL;\n-        options.save_acked_features = NULL;\n-        options.max_tx_queue_size = 0;\n-        options.is_vhost_user = false;\n-\n-        s->vhost_net = vhost_net_init(&options);\n-        if (!s->vhost_net) {\n-            error_setg(errp,\n-                       \"vhost-net requested but could not be initialized\");\n-            goto failed;\n-        }\n+    s->vhostfd = vhostfd;\n+    s->vhost_busyloop_timeout = tap->has_poll_us ? tap->poll_us : 0;\n+    if (!tap_setup_vhost(s, errp)) {\n+        return false;\n     }\n \n     return true;\n","prefixes":["v11","2/8"]}