From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 76212C83F17 for ; Mon, 14 Jul 2025 05:36:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ubBps-00017g-Hx; Mon, 14 Jul 2025 01:34:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubBpq-00013n-QP for qemu-devel@nongnu.org; Mon, 14 Jul 2025 01:34:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ubBpo-00036F-VG for qemu-devel@nongnu.org; Mon, 14 Jul 2025 01:34:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752471280; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=781Vd1RCDVNzKBhruVItGkuo2QXETHPOcYRirLtEix0=; b=bLRkn5eROSSG5ARSUWfoy0BcU80oSGOIoz2+qEl8QlorBAaUz9eja+fydJbWiW5fkdZDzd rOIJtM223PbielH6djWyuYGRBYI53qZABpeVZZRN1meMq9Zv+iyxqGCZlly+ZDCy4QisBS h9M4fKCmp7HV7d6f+KKy2jbtmjBO8vE= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-196-bYCz6XarMSmHZMUjjSaoaQ-1; Mon, 14 Jul 2025 01:34:38 -0400 X-MC-Unique: bYCz6XarMSmHZMUjjSaoaQ-1 X-Mimecast-MFC-AGG-ID: bYCz6XarMSmHZMUjjSaoaQ_1752471277 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6F11619560B0; Mon, 14 Jul 2025 05:34:37 +0000 (UTC) Received: from localhost.localdomain (unknown [10.72.112.55]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 8F7FE19560A3; Mon, 14 Jul 2025 05:34:34 +0000 (UTC) From: Jason Wang To: qemu-devel@nongnu.org Cc: Akihiko Odaki , Lei Yang , qemu-stable@nongnu.org, Jason Wang Subject: [PULL 02/13] virtio-net: Add queues for RSS during migration Date: Mon, 14 Jul 2025 13:34:12 +0800 Message-ID: <20250714053423.10415-3-jasowang@redhat.com> In-Reply-To: <20250714053423.10415-1-jasowang@redhat.com> References: <20250714053423.10415-1-jasowang@redhat.com> MIME-Version: 1.0 Content-type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Received-SPF: pass client-ip=170.10.133.124; envelope-from=jasowang@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, 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 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Akihiko Odaki virtio_net_pre_load_queues() inspects vdev->guest_features to tell if VIRTIO_NET_F_RSS or VIRTIO_NET_F_MQ is enabled to infer the required number of queues. This works for VIRTIO_NET_F_MQ but it doesn't for VIRTIO_NET_F_RSS because only the lowest 32 bits of vdev->guest_features is set at the point and VIRTIO_NET_F_RSS uses bit 60 while VIRTIO_NET_F_MQ uses bit 22. Instead of inferring the required number of queues from vdev->guest_features, use the number loaded from the vm state. This change also has a nice side effect to remove a duplicate peer queue pair change by circumventing virtio_net_set_multiqueue(). Also update the comment in include/hw/virtio/virtio.h to prevent an implementation of pre_load_queues() from refering to any fields being loaded during migration by accident in the future. Fixes: 8c49756825da ("virtio-net: Add only one queue pair when realizing") Tested-by: Lei Yang Cc: qemu-stable@nongnu.org Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 11 ++++------- hw/virtio/virtio.c | 14 +++++++------- include/hw/virtio/virtio.h | 10 ++++++++-- 3 files changed, 19 insertions(+), 16 deletions(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index eb93607b8c..351377c025 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -3022,11 +3022,10 @@ static void virtio_net_del_queue(VirtIONet *n, int index) virtio_del_queue(vdev, index * 2 + 1); } -static void virtio_net_change_num_queue_pairs(VirtIONet *n, int new_max_queue_pairs) +static void virtio_net_change_num_queues(VirtIONet *n, int new_num_queues) { VirtIODevice *vdev = VIRTIO_DEVICE(n); int old_num_queues = virtio_get_num_queues(vdev); - int new_num_queues = new_max_queue_pairs * 2 + 1; int i; assert(old_num_queues >= 3); @@ -3062,16 +3061,14 @@ static void virtio_net_set_multiqueue(VirtIONet *n, int multiqueue) int max = multiqueue ? n->max_queue_pairs : 1; n->multiqueue = multiqueue; - virtio_net_change_num_queue_pairs(n, max); + virtio_net_change_num_queues(n, max * 2 + 1); virtio_net_set_queue_pairs(n); } -static int virtio_net_pre_load_queues(VirtIODevice *vdev) +static int virtio_net_pre_load_queues(VirtIODevice *vdev, uint32_t n) { - virtio_net_set_multiqueue(VIRTIO_NET(vdev), - virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_RSS) || - virtio_has_feature(vdev->guest_features, VIRTIO_NET_F_MQ)); + virtio_net_change_num_queues(VIRTIO_NET(vdev), n); return 0; } diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 82a285a31d..7e38b1ca97 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -3270,13 +3270,6 @@ virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) config_len--; } - if (vdc->pre_load_queues) { - ret = vdc->pre_load_queues(vdev); - if (ret) { - return ret; - } - } - num = qemu_get_be32(f); if (num > VIRTIO_QUEUE_MAX) { @@ -3284,6 +3277,13 @@ virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) return -1; } + if (vdc->pre_load_queues) { + ret = vdc->pre_load_queues(vdev, num); + if (ret) { + return ret; + } + } + for (i = 0; i < num; i++) { vdev->vq[i].vring.num = qemu_get_be32(f); if (k->has_variable_vring_alignment) { diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 214d4a77e9..c594764f23 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -210,8 +210,14 @@ struct VirtioDeviceClass { void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask); int (*start_ioeventfd)(VirtIODevice *vdev); void (*stop_ioeventfd)(VirtIODevice *vdev); - /* Called before loading queues. Useful to add queues before loading. */ - int (*pre_load_queues)(VirtIODevice *vdev); + /* + * Called before loading queues. + * If the number of queues change at runtime, use @n to know the + * number and add or remove queues accordingly. + * Note that this function is called in the middle of loading vmsd; + * no assumption should be made on states being loaded from vmsd. + */ + int (*pre_load_queues)(VirtIODevice *vdev, uint32_t n); /* Saving and loading of a device; trying to deprecate save/load * use vmsd for new devices. */ -- 2.42.0