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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E6E9C433F5 for ; Wed, 25 May 2022 11:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241788AbiEYLAe (ORCPT ); Wed, 25 May 2022 07:00:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242480AbiEYLAE (ORCPT ); Wed, 25 May 2022 07:00:04 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 729AD5F8C9 for ; Wed, 25 May 2022 04:00:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653476402; 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=iHJ6PFjviDqPYy85yFDxjKt/WK/68mxqW6ae6Xic7iM=; b=h6VS+u5yDq0udPtoRRsKgUks1Btu7/67sWLB3scA4jdXzOo0/QwAbGV9WJ5qOb4l/l8akA XcSvxQ9hD0x5yZ1UWD8dGLBfsKa3w6hozJVLvj7hSXQMQITuEEke+R/QXXcw46qr58X1EG OKxRs8AeCen1LaBmKWWBAfjqHL3zsRU= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-392-QLLjc54rMoiQyA9K3FxXnA-1; Wed, 25 May 2022 06:59:57 -0400 X-MC-Unique: QLLjc54rMoiQyA9K3FxXnA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 603CE85A5BC; Wed, 25 May 2022 10:59:56 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.180]) by smtp.corp.redhat.com (Postfix) with ESMTP id 73FBE7AD8; Wed, 25 May 2022 10:59:48 +0000 (UTC) From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= To: "Michael S. Tsirkin" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, Jason Wang Cc: Zhu Lingshan , martinh@xilinx.com, Stefano Garzarella , ecree.xilinx@gmail.com, Eli Cohen , Dan Carpenter , Parav Pandit , Wu Zongyong , dinang@xilinx.com, Christophe JAILLET , Xie Yongji , gautam.dawar@amd.com, lulu@redhat.com, martinpo@xilinx.com, pabloc@xilinx.com, Longpeng , Piotr.Uminski@intel.com, tanuj.kamde@amd.com, Si-Wei Liu , habetsm.xilinx@gmail.com, lvivier@redhat.com, Zhang Min , hanand@xilinx.com Subject: [PATCH v3 2/4] vhost-vdpa: introduce STOP backend feature bit Date: Wed, 25 May 2022 12:59:20 +0200 Message-Id: <20220525105922.2413991-3-eperezma@redhat.com> In-Reply-To: <20220525105922.2413991-1-eperezma@redhat.com> References: <20220525105922.2413991-1-eperezma@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Userland knows if it can stop the device or not by checking this feature bit. It's only offered if the vdpa driver backend implements the stop() operation callback, and try to set it if the backend does not offer that callback is an error. Signed-off-by: Eugenio Pérez --- drivers/vhost/vdpa.c | 16 +++++++++++++++- include/uapi/linux/vhost_types.h | 2 ++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 1f1d1c425573..32713db5831d 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -347,6 +347,14 @@ static long vhost_vdpa_set_config(struct vhost_vdpa *v, return 0; } +static bool vhost_vdpa_can_stop(const struct vhost_vdpa *v) +{ + struct vdpa_device *vdpa = v->vdpa; + const struct vdpa_config_ops *ops = vdpa->config; + + return ops->stop; +} + static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) { struct vdpa_device *vdpa = v->vdpa; @@ -575,7 +583,11 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, if (cmd == VHOST_SET_BACKEND_FEATURES) { if (copy_from_user(&features, featurep, sizeof(features))) return -EFAULT; - if (features & ~VHOST_VDPA_BACKEND_FEATURES) + if (features & ~(VHOST_VDPA_BACKEND_FEATURES | + BIT_ULL(VHOST_BACKEND_F_STOP))) + return -EOPNOTSUPP; + if ((features & BIT_ULL(VHOST_BACKEND_F_STOP)) && + !vhost_vdpa_can_stop(v)) return -EOPNOTSUPP; vhost_set_backend_features(&v->vdev, features); return 0; @@ -624,6 +636,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, break; case VHOST_GET_BACKEND_FEATURES: features = VHOST_VDPA_BACKEND_FEATURES; + if (vhost_vdpa_can_stop(v)) + features |= BIT_ULL(VHOST_BACKEND_F_STOP); if (copy_to_user(featurep, &features, sizeof(features))) r = -EFAULT; break; diff --git a/include/uapi/linux/vhost_types.h b/include/uapi/linux/vhost_types.h index 634cee485abb..2758e665791b 100644 --- a/include/uapi/linux/vhost_types.h +++ b/include/uapi/linux/vhost_types.h @@ -161,5 +161,7 @@ struct vhost_vdpa_iova_range { * message */ #define VHOST_BACKEND_F_IOTLB_ASID 0x3 +/* Stop device from processing virtqueue buffers */ +#define VHOST_BACKEND_F_STOP 0x4 #endif -- 2.27.0