From patchwork Fri May 20 17:23:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 12857043 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 35BDFC433EF for ; Fri, 20 May 2022 17:24:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352207AbiETRYC (ORCPT ); Fri, 20 May 2022 13:24:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352189AbiETRXt (ORCPT ); Fri, 20 May 2022 13:23:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 48791187077 for ; Fri, 20 May 2022 10:23:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653067427; 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=RwJhQswXs8DRWPiKRZyfAdOUa8pNFYiVHsGQwvzSwJs=; b=ieNICIYMT63ycgR0NE+plLOdiT5xMlxnDfoad6L3ITRoOks24k6/MURtCHapUGt8z6Fvab 0fjRQMQEeCsRSPV99edcuZ33nuHO0TaDj4hX8KvvRvYsLT+eeD4EtwXVQXlYGGM/rNYgF/ GN1mZDAlI3KusS+qGmLiN90BBcO7trM= 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-595-hTE2Afj0PlaaSHtniuPgdA-1; Fri, 20 May 2022 13:23:44 -0400 X-MC-Unique: hTE2Afj0PlaaSHtniuPgdA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 83F088015BA; Fri, 20 May 2022 17:23:42 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.124]) by smtp.corp.redhat.com (Postfix) with ESMTP id CB6AF492C14; Fri, 20 May 2022 17:23:37 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: virtualization@lists.linux-foundation.org, Jason Wang , kvm@vger.kernel.org, "Michael S. Tsirkin" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Stefano Garzarella , Longpeng , Zhu Lingshan , martinh@xilinx.com, hanand@xilinx.com, Si-Wei Liu , dinang@xilinx.com, Eli Cohen , lvivier@redhat.com, pabloc@xilinx.com, gautam.dawar@amd.com, Xie Yongji , habetsm.xilinx@gmail.com, Christophe JAILLET , tanuj.kamde@amd.com, eperezma@redhat.com, Wu Zongyong , martinpo@xilinx.com, lulu@redhat.com, ecree.xilinx@gmail.com, Parav Pandit , Dan Carpenter , Zhang Min Subject: [PATCH 2/4] vhost-vdpa: introduce STOP backend feature bit Date: Fri, 20 May 2022 19:23:23 +0200 Message-Id: <20220520172325.980884-3-eperezma@redhat.com> In-Reply-To: <20220520172325.980884-1-eperezma@redhat.com> References: <20220520172325.980884-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: kvm@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 | 13 +++++++++++++ include/uapi/linux/vhost_types.h | 2 ++ 2 files changed, 15 insertions(+) diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index 1f1d1c425573..a325bc259afb 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; @@ -577,6 +585,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep, return -EFAULT; if (features & ~VHOST_VDPA_BACKEND_FEATURES) return -EOPNOTSUPP; + if ((features & VHOST_BACKEND_F_STOP) && + !vhost_vdpa_can_stop(v)) + return -EOPNOTSUPP; vhost_set_backend_features(&v->vdev, features); return 0; } @@ -624,6 +635,8 @@ 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 |= 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