From patchwork Fri Nov 20 18:50:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eugenio Perez Martin X-Patchwork-Id: 11922039 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35611C63777 for ; Fri, 20 Nov 2020 19:20:28 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 86599221F1 for ; Fri, 20 Nov 2020 19:20:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NeKpx8RD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86599221F1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35738 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kgBxK-00051z-IO for qemu-devel@archiver.kernel.org; Fri, 20 Nov 2020 14:20:26 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41890) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kgBZf-0007Rz-Bv for qemu-devel@nongnu.org; Fri, 20 Nov 2020 13:56:01 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:45921) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kgBZY-00086K-Ud for qemu-devel@nongnu.org; Fri, 20 Nov 2020 13:55:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605898551; 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=dZxEbXIS4zyXv2m5LGIw7P1HSVQ2S2HneDTGUSzuoD4=; b=NeKpx8RDCXzDnVnnSzOwCMIQ8c7SFIOlDZcO5QZWV5zm63yJ5FhSfj5feU2fgi6M/unwvz 14kE38Y+iNbaK3/Mqvr6bAk3I9U+UHkSo6/AQGONa+p65hTvK4V+OTH9fiv6VNJy8JY6G2 zI8QWUER6F5hagsRF+QxPfeV+It9FBk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-84-TAvJhVXkPzytOL7DCgwuCw-1; Fri, 20 Nov 2020 13:55:46 -0500 X-MC-Unique: TAvJhVXkPzytOL7DCgwuCw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A68DA8030A3; Fri, 20 Nov 2020 18:55:43 +0000 (UTC) Received: from eperezma.remote.csb (ovpn-112-88.ams2.redhat.com [10.36.112.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id 146EB5C1D5; Fri, 20 Nov 2020 18:55:30 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Subject: [RFC PATCH 19/27] vhost: add vhost_vring_get_buf_rcu Date: Fri, 20 Nov 2020 19:50:57 +0100 Message-Id: <20201120185105.279030-20-eperezma@redhat.com> In-Reply-To: <20201120185105.279030-1-eperezma@redhat.com> References: <20201120185105.279030-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Received-SPF: pass client-ip=63.128.21.124; envelope-from=eperezma@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_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" , Jason Wang , Daniel Daly , virtualization@lists.linux-foundation.org, Liran Alon , Eli Cohen , Nitin Shrivastav , Alex Barba , Christophe Fontaine , Juan Quintela , Lee Ballard , Lars Ganrot , Rob Miller , Stefano Garzarella , Howard Cai , Parav Pandit , vm , Salil Mehta , Stephen Finucane , Xiao W Wang , Sean Mooney , Stefan Hajnoczi , Jim Harford , Dmytro Kazantsev , Siwei Liu , Harpreet Singh Anand , Michael Lilja , Max Gurtovoy Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Eugenio Pérez --- hw/virtio/vhost-sw-lm-ring.h | 1 + hw/virtio/vhost-sw-lm-ring.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/hw/virtio/vhost-sw-lm-ring.h b/hw/virtio/vhost-sw-lm-ring.h index 03257d60c1..429a125558 100644 --- a/hw/virtio/vhost-sw-lm-ring.h +++ b/hw/virtio/vhost-sw-lm-ring.h @@ -19,6 +19,7 @@ typedef struct VhostShadowVirtqueue VhostShadowVirtqueue; bool vhost_vring_kick(VhostShadowVirtqueue *vq); int vhost_vring_add(VhostShadowVirtqueue *vq, VirtQueueElement *elem); +VirtQueueElement *vhost_vring_get_buf_rcu(VhostShadowVirtqueue *vq, size_t sz); /* Called within rcu_read_lock(). */ void vhost_vring_set_notification_rcu(VhostShadowVirtqueue *vq, bool enable); diff --git a/hw/virtio/vhost-sw-lm-ring.c b/hw/virtio/vhost-sw-lm-ring.c index 3652889d8e..4fafd1b278 100644 --- a/hw/virtio/vhost-sw-lm-ring.c +++ b/hw/virtio/vhost-sw-lm-ring.c @@ -187,6 +187,35 @@ int vhost_vring_add(VhostShadowVirtqueue *vq, VirtQueueElement *elem) return 0; } +VirtQueueElement *vhost_vring_get_buf_rcu(VhostShadowVirtqueue *vq, size_t sz) +{ + const vring_used_t *used = vq->vring.used; + VirtQueueElement *ret; + vring_used_elem_t used_elem; + uint16_t last_used; + + if (!vhost_vring_poll_rcu(vq)) { + return NULL; + } + + last_used = vq->used_idx & (vq->vring.num - 1); + used_elem.id = virtio_tswap32(vq->vdev, used->ring[last_used].id); + used_elem.len = virtio_tswap32(vq->vdev, used->ring[last_used].len); + + if (unlikely(used_elem.id >= vq->vring.num)) { + virtio_error(vq->vdev, "Device says index %u is available", + used_elem.id); + return NULL; + } + + ret = vq->ring_id_maps[used_elem.id]; + ret->len = used_elem.len; + + vq->used_idx++; + + return ret; +} + void vhost_vring_write_addr(const VhostShadowVirtqueue *vq, struct vhost_vring_addr *addr) {