From nobody Mon Feb 9 06:44:18 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=quarantine dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1755081047; cv=none; d=zohomail.com; s=zohoarc; b=Jhfs45k+fq4OBxtKfProRq30bTpyKZCSD+CU/IFgXpfRAAipENibJn6iduLDjZlnHH88SIZkdLKAGA/C5hfCc3raTE+dfFHP3IxjV4LP2YPaJUGiQz/PGzu+ssY7uv+4whMMMsEdsJF1TybhWP0a7a8aOsXu1wG/CPH8Y+eNl5k= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1755081047; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:Subject:To:To:Message-Id:Reply-To; bh=PHPIfm2gD5x7SK9k9ayiZrFhwzAZ5Cctq1V4SO+lO4I=; b=f6nZmDLzNygwn4t1J1RwcjvEqeFfoLDL1l0S/hwom6j0upqecW5I2bIBJDWZBWWoI40LIXqwtYKeNiINj5j1ny5az/JJ4ygdKwvmVUR1YWKNucXhgIiX06myNVjX0nVVGLMSOcrxgH5tMR4UkWpRkEtNoEO2vTBFIg6xRVGBAwQ= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=quarantine dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1755081047891416.2702556288185; Wed, 13 Aug 2025 03:30:47 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1um8kN-00005H-Of; Wed, 13 Aug 2025 06:30:19 -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 1um8kM-0008VQ-2A for qemu-devel@nongnu.org; Wed, 13 Aug 2025 06:30:18 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1um8kE-0007s5-Cr for qemu-devel@nongnu.org; Wed, 13 Aug 2025 06:30:17 -0400 Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-313-ApQgirF1OHaP6FvjmWhUUw-1; Wed, 13 Aug 2025 06:30:07 -0400 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7F7911800345; Wed, 13 Aug 2025 10:30:06 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.45.224.219]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id EAED51955E88; Wed, 13 Aug 2025 10:30:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755081008; 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=PHPIfm2gD5x7SK9k9ayiZrFhwzAZ5Cctq1V4SO+lO4I=; b=gTxAglf5YyVU7wwsyZZndf66Bs7HlcCkHTaYxI8prF9StQuPDL6IgBgC9q8IL3hHLxQX7d +vJWhtoBnMS9a2RcmjpMR4oJ0JhSxzDaLnpWYSPJ3T+mS3mvVq9tZvDJ0vWSMYM5lh5b7L M2KeWnUfhsS8/I75mUwGy2isbdSN7q8= X-MC-Unique: ApQgirF1OHaP6FvjmWhUUw-1 X-Mimecast-MFC-AGG-ID: ApQgirF1OHaP6FvjmWhUUw_1755081006 From: Paolo Abeni To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Akihiko Odaki , Jason Wang , "Michael S. Tsirkin" , Stefano Garzarella , Cornelia Huck , Eric Blake , Markus Armbruster Subject: [PATCH v5 09/13] vhost-backend: implement extended features support Date: Wed, 13 Aug 2025 12:28:22 +0200 Message-ID: <4361056cae3adf74132d6d24a4b8afe895e2f31a.1755080614.git.pabeni@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.129.124; 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, T_SPF_TEMPERROR=0.01 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1755081052128124100 Content-Type: text/plain; charset="utf-8" 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 --- v3 -> v4: - use new virtio_features macro names 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..4367db0d95 100644 --- a/hw/virtio/vhost-backend.c +++ b/hw/virtio/vhost-backend.c @@ -20,6 +20,11 @@ #include #include =20 +struct vhost_features { + uint64_t count; + uint64_t features[VIRTIO_FEATURES_NU64S]; +}; + static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int requ= est, 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); } =20 -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; } =20 -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 =3D VIRTIO_FEATURES_NU64S; + virtio_features_copy(farray.features, features); + extended_in_use =3D virtio_features_use_ex(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 valida= ting + * such id, instead of reporting an unknown operation. + */ + r =3D 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 suppo= rt"); + 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 *feat= ures) +{ + struct vhost_features farray; + int r; + + farray.count =3D VIRTIO_FEATURES_NU64S; + r =3D vhost_kernel_call(dev, VHOST_GET_FEATURES_ARRAY, &farray); + if (r) { + memset(&farray, 0, sizeof(farray)); + r =3D vhost_kernel_call(dev, VHOST_GET_FEATURES, &farray.features[= 0]); + } + if (r) { + return r; + } + + virtio_features_copy(features, farray.features); + return 0; } =20 static int vhost_kernel_set_owner(struct vhost_dev *dev) @@ -341,8 +381,8 @@ const VhostOps kernel_ops =3D { .vhost_attach_vring_worker =3D vhost_kernel_attach_vring_worker, .vhost_new_worker =3D vhost_kernel_new_worker, .vhost_free_worker =3D vhost_kernel_free_worker, - .vhost_set_features =3D vhost_kernel_set_features, - .vhost_get_features =3D vhost_kernel_get_features, + .vhost_set_features_ex =3D vhost_kernel_set_features, + .vhost_get_features_ex =3D vhost_kernel_get_features, .vhost_set_backend_cap =3D vhost_kernel_set_backend_cap, .vhost_set_owner =3D vhost_kernel_set_owner, .vhost_get_vq_index =3D vhost_kernel_get_vq_index, --=20 2.50.1