From patchwork Thu Jul 14 16:31:47 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: 1656546 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=ZTz46xYI; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) 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 bilbo.ozlabs.org (Postfix) with ESMTPS id 4LkL0X3zKPz9sGD for ; Fri, 15 Jul 2022 02:43:40 +1000 (AEST) Received: from localhost ([::1]:56274 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oC1w9-00005s-Ao for incoming@patchwork.ozlabs.org; Thu, 14 Jul 2022 12:43:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36984) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oC1lm-00083Y-Ns for qemu-devel@nongnu.org; Thu, 14 Jul 2022 12:32:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:20310) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oC1li-0003Uc-NW for qemu-devel@nongnu.org; Thu, 14 Jul 2022 12:32:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657816370; 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=dgW3tb8E1zv1U1kT7LT+41RhB7zKrEFf3AsAF9oGxzI=; b=ZTz46xYIiEiVKkWoYFh/XkqyjC1W5vwtBd6MEK6DQUngLsc3FEi24t8BtzeBcJzQnglg9T jKRcF1gzWDYcGw9TwoQ1pEy7U6rstyYT+UX952LbnIYHe+XUDRjUds+STOn8jxYlJ2//Px CrSDq5i3Zv0kowFd30PTjG1oFh0npHg= 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-647-hnTDWpxDM_WQXxiVo-Zs9w-1; Thu, 14 Jul 2022 12:32:46 -0400 X-MC-Unique: hnTDWpxDM_WQXxiVo-Zs9w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0164B801231; Thu, 14 Jul 2022 16:32:46 +0000 (UTC) Received: from eperezma.remote.csb (unknown [10.39.192.102]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2517C1121314; Thu, 14 Jul 2022 16:32:43 +0000 (UTC) From: =?utf-8?q?Eugenio_P=C3=A9rez?= To: qemu-devel@nongnu.org Cc: Gautam Dawar , Paolo Bonzini , "Michael S. Tsirkin" , Stefano Garzarella , Eric Blake , Zhu Lingshan , Stefan Hajnoczi , Markus Armbruster , Cornelia Huck , Parav Pandit , Laurent Vivier , Liuxiangdong , Eli Cohen , Cindy Lu , Harpreet Singh Anand , Jason Wang , "Gonglei (Arei)" Subject: [PATCH v2 16/19] vdpa: Buffer CVQ support on shadow virtqueue Date: Thu, 14 Jul 2022 18:31:47 +0200 Message-Id: <20220714163150.2536327-17-eperezma@redhat.com> In-Reply-To: <20220714163150.2536327-1-eperezma@redhat.com> References: <20220714163150.2536327-1-eperezma@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eperezma@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Introduce the control virtqueue support for vDPA shadow virtqueue. This is needed for advanced networking features like rx filtering. Virtio-net control VQ copies the descriptors to qemu's VA, so we avoid TOCTOU with the guest's or device's memory every time there is a device model change. Otherwise, the guest could change the memory content in the time between qemu and the device read it. To demonstrate command handling, VIRTIO_NET_F_CTRL_MACADDR is implemented. If the virtio-net driver changes MAC the virtio-net device model will be updated with the new one, and a rx filtering change event will be raised. More cvq commands could be added here straightforwardly but they have not been tested. Signed-off-by: Eugenio Pérez --- net/vhost-vdpa.c | 211 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 204 insertions(+), 7 deletions(-) diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index 805c9dd6b6..bc115a1455 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -33,6 +33,9 @@ typedef struct VhostVDPAState { NetClientState nc; struct vhost_vdpa vhost_vdpa; VHostNetState *vhost_net; + + /* Control commands shadow buffers */ + void *cvq_cmd_out_buffer, *cvq_cmd_in_buffer; bool started; } VhostVDPAState; @@ -131,6 +134,8 @@ static void vhost_vdpa_cleanup(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); + qemu_vfree(s->cvq_cmd_out_buffer); + qemu_vfree(s->cvq_cmd_in_buffer); if (s->vhost_net) { vhost_net_cleanup(s->vhost_net); g_free(s->vhost_net); @@ -190,24 +195,191 @@ static NetClientInfo net_vhost_vdpa_info = { .check_peer_type = vhost_vdpa_check_peer_type, }; +static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr) +{ + VhostIOVATree *tree = v->iova_tree; + DMAMap needle = { + /* + * No need to specify size or to look for more translations since + * this contiguous chunk was allocated by us. + */ + .translated_addr = (hwaddr)(uintptr_t)addr, + }; + const DMAMap *map = vhost_iova_tree_find_iova(tree, &needle); + int r; + + if (unlikely(!map)) { + error_report("Cannot locate expected map"); + return; + } + + r = vhost_vdpa_dma_unmap(v, map->iova, map->size + 1); + if (unlikely(r != 0)) { + error_report("Device cannot unmap: %s(%d)", g_strerror(r), r); + } + + vhost_iova_tree_remove(tree, map); +} + +static size_t vhost_vdpa_net_cvq_cmd_len(void) +{ + /* + * MAC_TABLE_SET is the ctrl command that produces the longer out buffer. + * In buffer is always 1 byte, so it should fit here + */ + return sizeof(struct virtio_net_ctrl_hdr) + + 2 * sizeof(struct virtio_net_ctrl_mac) + + MAC_TABLE_ENTRIES * ETH_ALEN; +} + +static size_t vhost_vdpa_net_cvq_cmd_page_len(void) +{ + return ROUND_UP(vhost_vdpa_net_cvq_cmd_len(), qemu_real_host_page_size()); +} + +/** Copy and map a guest buffer. */ +static bool vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, + const struct iovec *out_data, + size_t out_num, size_t data_len, void *buf, + size_t *written, bool write) +{ + DMAMap map = {}; + int r; + + if (unlikely(!data_len)) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid legnth of %s buffer\n", + __func__, write ? "in" : "out"); + return false; + } + + *written = iov_to_buf(out_data, out_num, 0, buf, data_len); + map.translated_addr = (hwaddr)(uintptr_t)buf; + map.size = vhost_vdpa_net_cvq_cmd_page_len() - 1; + map.perm = write ? IOMMU_RW : IOMMU_RO, + r = vhost_iova_tree_map_alloc(v->iova_tree, &map); + if (unlikely(r != IOVA_OK)) { + error_report("Cannot map injected element"); + return false; + } + + r = vhost_vdpa_dma_map(v, map.iova, vhost_vdpa_net_cvq_cmd_page_len(), buf, + !write); + if (unlikely(r < 0)) { + goto dma_map_err; + } + + return true; + +dma_map_err: + vhost_iova_tree_remove(v->iova_tree, &map); + return false; +} + /** - * Forward buffer for the moment. + * Copy the guest element into a dedicated buffer suitable to be sent to NIC + * + * @iov: [0] is the out buffer, [1] is the in one + */ +static bool vhost_vdpa_net_cvq_map_elem(VhostVDPAState *s, + VirtQueueElement *elem, + struct iovec *iov) +{ + size_t in_copied; + bool ok; + + iov[0].iov_base = s->cvq_cmd_out_buffer; + ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, elem->out_sg, elem->out_num, + vhost_vdpa_net_cvq_cmd_len(), iov[0].iov_base, + &iov[0].iov_len, false); + if (unlikely(!ok)) { + return false; + } + + iov[1].iov_base = s->cvq_cmd_in_buffer; + ok = vhost_vdpa_cvq_map_buf(&s->vhost_vdpa, NULL, 0, + sizeof(virtio_net_ctrl_ack), iov[1].iov_base, + &in_copied, true); + if (unlikely(!ok)) { + vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer); + return false; + } + + iov[1].iov_len = sizeof(virtio_net_ctrl_ack); + return true; +} + +/** + * Do not forward commands not supported by SVQ. Otherwise, the device could + * accept it and qemu would not know how to update the device model. + */ +static bool vhost_vdpa_net_cvq_validate_cmd(const struct iovec *out, + size_t out_num) +{ + struct virtio_net_ctrl_hdr ctrl; + size_t n; + + n = iov_to_buf(out, out_num, 0, &ctrl, sizeof(ctrl)); + if (unlikely(n < sizeof(ctrl))) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: invalid legnth of out buffer %zu\n", __func__, n); + return false; + } + + switch (ctrl.class) { + case VIRTIO_NET_CTRL_MAC: + switch (ctrl.cmd) { + case VIRTIO_NET_CTRL_MAC_ADDR_SET: + return true; + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid mac cmd %u\n", + __func__, ctrl.cmd); + }; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid control class %u\n", + __func__, ctrl.class); + }; + + return false; +} + +/** + * Validate and copy control virtqueue commands. + * + * Following QEMU guidelines, we offer a copy of the buffers to the device to + * prevent TOCTOU bugs. */ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq, SVQElement *svq_elem, void *opaque) { VirtQueueElement *elem = &svq_elem->elem; - unsigned int n = elem->out_num + elem->in_num; - g_autofree struct iovec *dev_buffers = g_new(struct iovec, n); + VhostVDPAState *s = opaque; size_t in_len, dev_written; virtio_net_ctrl_ack status = VIRTIO_NET_ERR; + /* out and in buffers sent to the device */ + struct iovec dev_buffers[2] = { + { .iov_base = s->cvq_cmd_out_buffer }, + { .iov_base = s->cvq_cmd_in_buffer }, + }; + /* in buffer used for device model */ + const struct iovec in = { + .iov_base = &status, + .iov_len = sizeof(status), + }; int r; + bool ok; - memcpy(dev_buffers, elem->out_sg, elem->out_num); - memcpy(dev_buffers + elem->out_num, elem->in_sg, elem->in_num); + ok = vhost_vdpa_net_cvq_map_elem(s, elem, dev_buffers); + if (unlikely(!ok)) { + goto out; + } - r = vhost_svq_add(svq, &dev_buffers[0], elem->out_num, &dev_buffers[1], - elem->in_num, svq_elem); + ok = vhost_vdpa_net_cvq_validate_cmd(&dev_buffers[0], 1); + if (unlikely(!ok)) { + goto out; + } + + r = vhost_svq_add(svq, &dev_buffers[0], 1, &dev_buffers[1], 1, svq_elem); if (unlikely(r != 0)) { if (unlikely(r == -ENOSPC)) { qemu_log_mask(LOG_GUEST_ERROR, "%s: No space on device queue\n", @@ -224,6 +396,18 @@ static int vhost_vdpa_net_handle_ctrl_avail(VhostShadowVirtqueue *svq, dev_written = vhost_svq_poll(svq); if (unlikely(dev_written < sizeof(status))) { error_report("Insufficient written data (%zu)", dev_written); + goto out; + } + + memcpy(&status, dev_buffers[1].iov_base, sizeof(status)); + if (status != VIRTIO_NET_OK) { + goto out; + } + + status = VIRTIO_NET_ERR; + virtio_net_handle_ctrl_iov(svq->vdev, &in, 1, dev_buffers, 1); + if (status != VIRTIO_NET_OK) { + error_report("Bad CVQ processing in model"); } out: @@ -234,6 +418,12 @@ out: } vhost_svq_push_elem(svq, svq_elem, MIN(in_len, sizeof(status))); g_free(svq_elem); + if (dev_buffers[0].iov_base) { + vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[0].iov_base); + } + if (dev_buffers[1].iov_base) { + vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, dev_buffers[1].iov_base); + } return r; } @@ -266,6 +456,13 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer, s->vhost_vdpa.device_fd = vdpa_device_fd; s->vhost_vdpa.index = queue_pair_index; if (!is_datapath) { + s->cvq_cmd_out_buffer = qemu_memalign(qemu_real_host_page_size(), + vhost_vdpa_net_cvq_cmd_page_len()); + memset(s->cvq_cmd_out_buffer, 0, vhost_vdpa_net_cvq_cmd_page_len()); + s->cvq_cmd_in_buffer = qemu_memalign(qemu_real_host_page_size(), + vhost_vdpa_net_cvq_cmd_page_len()); + memset(s->cvq_cmd_in_buffer, 0, vhost_vdpa_net_cvq_cmd_page_len()); + s->vhost_vdpa.shadow_vq_ops = &vhost_vdpa_net_svq_ops; s->vhost_vdpa.shadow_vq_ops_opaque = s; }