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 124D5C83F1A for ; Fri, 18 Jul 2025 08:54:43 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ucgrB-0002Cg-W9; Fri, 18 Jul 2025 04:54:19 -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 1ucgr1-00026A-GK for qemu-devel@nongnu.org; Fri, 18 Jul 2025 04:54:07 -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 1ucgqz-0001If-9L for qemu-devel@nongnu.org; Fri, 18 Jul 2025 04:54:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752828844; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SL+GETdKban5g91ExaSvmecQrNfHVSXJ9ooj81M5Q9A=; b=SpStsfY7hKr9Ub0XxdFNPK2zgGtwAaDsN16e88F/NOnwQJs3SbuZhw5WKOWARr+/+aQFdh HQ3XE0nHaL7Judt0Sol1/otNEDoWlOHrA/gwd6P6S8RGLVUPtIDp4ogeh6iDKEA/na6q/t /QRUN2g2jmNQaZsGDBq4CgnSVzbOHcg= 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-466-EGYlpH9cPLa66DIJxssMAA-1; Fri, 18 Jul 2025 04:54:01 -0400 X-MC-Unique: EGYlpH9cPLa66DIJxssMAA-1 X-Mimecast-MFC-AGG-ID: EGYlpH9cPLa66DIJxssMAA_1752828839 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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 6BF6619560B3; Fri, 18 Jul 2025 08:53:59 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.44.33.19]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 7751C1956089; Fri, 18 Jul 2025 08:53:54 +0000 (UTC) From: Paolo Abeni To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Dmitry Fleytman , Akihiko Odaki , Jason Wang , Sriram Yagnaraman , "Michael S. Tsirkin" , Stefano Garzarella , Cornelia Huck , Luigi Rizzo , Giuseppe Lettieri , Vincenzo Maffione , Eric Blake , Markus Armbruster Subject: [PATCH RFC v3 09/13] vhost-backend: implement extended features support Date: Fri, 18 Jul 2025 10:52:35 +0200 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.133.124; envelope-from=pabeni@redhat.com; helo=us-smtp-delivery-124.mimecast.com 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, 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=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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 Leverage the kernel extended features manipulation ioctls(), if available, and fallback to old ops otherwise. Error out when setting extended features but kernel support is not available. Note that extended support for get/set backend features is not needed, as the only feature that can be changed belongs to the 64 bit range. Signed-off-by: Paolo Abeni --- v1 -> v2: - synced with kernel ioctl changes --- hw/virtio/vhost-backend.c | 62 ++++++++++++++++++++++++++++++++------- 1 file changed, 51 insertions(+), 11 deletions(-) diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c index 833804dd40..6fde994403 100644 --- a/hw/virtio/vhost-backend.c +++ b/hw/virtio/vhost-backend.c @@ -20,6 +20,11 @@ #include #include +struct vhost_features { + uint64_t count; + uint64_t features[VIRTIO_FEATURES_DWORDS]; +}; + static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request, void *arg) { @@ -182,12 +187,6 @@ static int vhost_kernel_get_vring_worker(struct vhost_dev *dev, return vhost_kernel_call(dev, VHOST_GET_VRING_WORKER, worker); } -static int vhost_kernel_set_features(struct vhost_dev *dev, - uint64_t features) -{ - return vhost_kernel_call(dev, VHOST_SET_FEATURES, &features); -} - static int vhost_kernel_set_backend_cap(struct vhost_dev *dev) { uint64_t features; @@ -210,10 +209,51 @@ static int vhost_kernel_set_backend_cap(struct vhost_dev *dev) return 0; } -static int vhost_kernel_get_features(struct vhost_dev *dev, - uint64_t *features) +static int vhost_kernel_set_features(struct vhost_dev *dev, + const uint64_t *features) { - return vhost_kernel_call(dev, VHOST_GET_FEATURES, features); + struct vhost_features farray; + bool extended_in_use; + int r; + + farray.count = VIRTIO_FEATURES_DWORDS; + virtio_features_copy(farray.features, features); + extended_in_use = virtio_features_use_extended(farray.features); + + /* + * Can't check for ENOTTY: for unknown ioctls the kernel interprets + * the argument as a virtio queue id and most likely errors out validating + * such id, instead of reporting an unknown operation. + */ + r = vhost_kernel_call(dev, VHOST_SET_FEATURES_ARRAY, &farray); + if (!r) { + return 0; + } + + if (extended_in_use) { + error_report("Trying to set extended features without kernel support"); + return -EINVAL; + } + return vhost_kernel_call(dev, VHOST_SET_FEATURES, &farray.features[0]); +} + +static int vhost_kernel_get_features(struct vhost_dev *dev, uint64_t *features) +{ + struct vhost_features farray; + int r; + + farray.count = VIRTIO_FEATURES_DWORDS; + r = vhost_kernel_call(dev, VHOST_GET_FEATURES_ARRAY, &farray); + if (r) { + memset(&farray, 0, sizeof(farray)); + r = vhost_kernel_call(dev, VHOST_GET_FEATURES, &farray.features[0]); + } + if (r) { + return r; + } + + virtio_features_copy(features, farray.features); + return 0; } static int vhost_kernel_set_owner(struct vhost_dev *dev) @@ -341,8 +381,8 @@ const VhostOps kernel_ops = { .vhost_attach_vring_worker = vhost_kernel_attach_vring_worker, .vhost_new_worker = vhost_kernel_new_worker, .vhost_free_worker = vhost_kernel_free_worker, - .vhost_set_features = vhost_kernel_set_features, - .vhost_get_features = vhost_kernel_get_features, + .vhost_set_features_ex = vhost_kernel_set_features, + .vhost_get_features_ex = vhost_kernel_get_features, .vhost_set_backend_cap = vhost_kernel_set_backend_cap, .vhost_set_owner = vhost_kernel_set_owner, .vhost_get_vq_index = vhost_kernel_get_vq_index, -- 2.50.0