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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 4D5BDC433F5 for ; Tue, 7 Dec 2021 09:50:57 +0000 (UTC) Received: from localhost ([::1]:48570 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1muX7g-0002zS-67 for qemu-devel@archiver.kernel.org; Tue, 07 Dec 2021 04:50:56 -0500 Received: from eggs.gnu.org ([209.51.188.92]:56354) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1muX5k-0000bc-4L for qemu-devel@nongnu.org; Tue, 07 Dec 2021 04:48:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:50525) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1muX5g-0006IF-Bb for qemu-devel@nongnu.org; Tue, 07 Dec 2021 04:48:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1638870531; 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: in-reply-to:in-reply-to:references:references; bh=7GAlrN7VXXETc9qtGGCyCZNAw98uPhOK3+6hzQzsvng=; b=Xkj5THqmqXnP6YfArArV0D5d2Vw4UxJoGArN5OCUH+xuNK4s50T8EZdgpA3NxZU2diXLFl tAt2cfVPuRGtAlQAfibeA7RIGAg0cwpcvGogAg+6cKtHMO0R0+ahzpA31m2EpYEGgYWEsh IEKFKa+GSGVzB4GiSA8j48UXQYk2bg0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-423-JlMdFcOWMWC51hWwOK2SRQ-1; Tue, 07 Dec 2021 04:48:49 -0500 X-MC-Unique: JlMdFcOWMWC51hWwOK2SRQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E0472835E26; Tue, 7 Dec 2021 09:48:47 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-7.ams2.redhat.com [10.36.112.7]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 14AF61346F; Tue, 7 Dec 2021 09:48:05 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 979B2113865F; Tue, 7 Dec 2021 10:48:03 +0100 (CET) From: Markus Armbruster To: Jonah Palmer Subject: Re: [PATCH v10 7/8] qmp: add QMP command x-query-virtio-queue-element References: <1638794606-19631-1-git-send-email-jonah.palmer@oracle.com> <1638794606-19631-8-git-send-email-jonah.palmer@oracle.com> Date: Tue, 07 Dec 2021 10:48:03 +0100 In-Reply-To: <1638794606-19631-8-git-send-email-jonah.palmer@oracle.com> (Jonah Palmer's message of "Mon, 6 Dec 2021 07:43:25 -0500") Message-ID: <87lf0wd9v0.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.619, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mst@redhat.com, qemu_oss@crudebyte.com, qemu-devel@nongnu.org, kraxel@redhat.com, si-wei.liu@oracle.com, joao.m.martins@oracle.com, eblake@redhat.com, qemu-block@nongnu.org, david@redhat.com, arei.gonglei@huawei.com, marcandre.lureau@redhat.com, lvivier@redhat.com, thuth@redhat.com, michael.roth@amd.com, groug@kaod.org, dgilbert@redhat.com, eric.auger@redhat.com, stefanha@redhat.com, boris.ostrovsky@oracle.com, kwolf@redhat.com, mathieu.poirier@linaro.org, raphael.norwitz@nutanix.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Jonah Palmer writes: > From: Laurent Vivier > > This new command shows the information of a VirtQueue element. > > Signed-off-by: Jonah Palmer > --- > hw/virtio/virtio-stub.c | 9 +++ > hw/virtio/virtio.c | 154 ++++++++++++++++++++++++++++++++++++++++ > qapi/virtio.json | 183 ++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 346 insertions(+) > > diff --git a/hw/virtio/virtio-stub.c b/hw/virtio/virtio-stub.c > index 13e5f93..7ddb22c 100644 > --- a/hw/virtio/virtio-stub.c > +++ b/hw/virtio/virtio-stub.c > @@ -31,3 +31,12 @@ VirtQueueStatus *qmp_x_query_virtio_queue_status(const char *path, > { > return qmp_virtio_unsupported(errp); > } > + > +VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path, > + uint16_t queue, > + bool has_index, > + uint16_t index, > + Error **errp) > +{ > + return qmp_virtio_unsupported(errp); > +} > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 459bfb2..8c6cc27 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -475,6 +475,19 @@ static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem, > address_space_cache_invalidate(&caches->used, pa, sizeof(VRingUsedElem)); > } > > +/* Called within rcu_read_lock(). */ > +static inline uint16_t vring_used_flags(VirtQueue *vq) > +{ > + VRingMemoryRegionCaches *caches = vring_get_region_caches(vq); > + hwaddr pa = offsetof(VRingUsed, flags); > + > + if (!caches) { > + return 0; > + } > + > + return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa); > +} > + > /* Called within rcu_read_lock(). */ > static uint16_t vring_used_idx(VirtQueue *vq) > { > @@ -4381,6 +4394,147 @@ VirtQueueStatus *qmp_x_query_virtio_queue_status(const char *path, > return status; > } > > +static strList *qmp_decode_vring_desc_flags(uint16_t flags) > +{ > + strList *list = NULL; > + strList *node; > + int i; > + > + struct { > + uint16_t flag; > + const char *value; > + } map[] = { > + { VRING_DESC_F_NEXT, "next" }, > + { VRING_DESC_F_WRITE, "write" }, > + { VRING_DESC_F_INDIRECT, "indirect" }, > + { 1 << VRING_PACKED_DESC_F_AVAIL, "avail" }, > + { 1 << VRING_PACKED_DESC_F_USED, "used" }, > + { 0, "" } > + }; > + > + for (i = 0; map[i].flag; i++) { > + if ((map[i].flag & flags) == 0) { > + continue; > + } > + node = g_malloc0(sizeof(strList)); > + node->value = g_strdup(map[i].value); > + node->next = list; > + list = node; > + } > + > + return list; > +} > + > +VirtioQueueElement *qmp_x_query_virtio_queue_element(const char *path, > + uint16_t queue, > + bool has_index, > + uint16_t index, > + Error **errp) > +{ > + VirtIODevice *vdev; > + VirtQueue *vq; > + VirtioQueueElement *element = NULL; > + > + vdev = virtio_device_find(path); > + if (vdev == NULL) { > + error_setg(errp, "Path %s is not a VirtIO device", path); > + return NULL; > + } > + > + if (queue >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, queue)) { > + error_setg(errp, "Invalid virtqueue number %d", queue); > + return NULL; > + } > + vq = &vdev->vq[queue]; > + > + if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) { > + error_setg(errp, "Packed ring not supported"); > + return NULL; > + } else { > + unsigned int head, i, max; > + VRingMemoryRegionCaches *caches; > + MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; > + MemoryRegionCache *desc_cache; > + VRingDesc desc; > + VirtioRingDescList *list = NULL; > + VirtioRingDescList *node; > + int rc; int ndescs; > + > + RCU_READ_LOCK_GUARD(); > + > + max = vq->vring.num; > + > + if (!has_index) { > + head = vring_avail_ring(vq, vq->last_avail_idx % vq->vring.num); > + } else { > + head = vring_avail_ring(vq, index % vq->vring.num); > + } > + i = head; > + > + caches = vring_get_region_caches(vq); > + if (!caches) { > + error_setg(errp, "Region caches not initialized"); > + return NULL; > + } > + if (caches->desc.len < max * sizeof(VRingDesc)) { > + error_setg(errp, "Cannot map descriptor ring"); > + return NULL; > + } > + > + desc_cache = &caches->desc; > + vring_split_desc_read(vdev, &desc, desc_cache, i); > + if (desc.flags & VRING_DESC_F_INDIRECT) { > + int64_t len; > + len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, > + desc.addr, desc.len, false); > + desc_cache = &indirect_desc_cache; > + if (len < desc.len) { > + error_setg(errp, "Cannot map indirect buffer"); > + goto done; > + } > + > + max = desc.len / sizeof(VRingDesc); > + i = 0; > + vring_split_desc_read(vdev, &desc, desc_cache, i); > + } > + > + element = g_new0(VirtioQueueElement, 1); > + element->avail = g_new0(VirtioRingAvail, 1); > + element->used = g_new0(VirtioRingUsed, 1); > + element->name = g_strdup(vdev->name); > + element->index = head; > + element->avail->flags = vring_avail_flags(vq); > + element->avail->idx = vring_avail_idx(vq); > + element->avail->ring = head; > + element->used->flags = vring_used_flags(vq); > + element->used->idx = vring_used_idx(vq); > + ndescs = 0; > + > + do { > + /* A buggy driver may produce an infinite loop */ > + if (ndescs >= max) { > + break; > + } > + node = g_new0(VirtioRingDescList, 1); > + node->value = g_new0(VirtioRingDesc, 1); > + node->value->addr = desc.addr; > + node->value->len = desc.len; > + node->value->flags = qmp_decode_vring_desc_flags(desc.flags); > + node->next = list; > + list = node; > + > + ndescs++; > + rc = virtqueue_split_read_next_desc(vdev, &desc, desc_cache, > + max, &i); > + } while (rc == VIRTQUEUE_READ_DESC_MORE); > + element->descs = list; > +done: > + address_space_cache_destroy(&indirect_desc_cache); > + } > + > + return element; > +} > + > static const TypeInfo virtio_device_info = { > .name = TYPE_VIRTIO_DEVICE, > .parent = TYPE_DEVICE, > diff --git a/qapi/virtio.json b/qapi/virtio.json > index 56e56d2..2984e48 100644 > --- a/qapi/virtio.json > +++ b/qapi/virtio.json > @@ -654,3 +654,186 @@ > 'data': { 'path': 'str', 'queue': 'uint16' }, > 'returns': 'VirtVhostQueueStatus', > 'features': [ 'unstable' ] } > + > +## > +# @VirtioRingDesc: > +# > +# Information regarding the vring descriptor area > +# > +# @addr: Guest physical address of the descriptor area > +# > +# @len: Length of the descriptor area > +# > +# @flags: List of descriptor flags > +# > +# Since: 7.0 > +# > +## > + > +{ 'struct': 'VirtioRingDesc', > + 'data': { 'addr': 'uint64', > + 'len': 'uint32', > + 'flags': [ 'str' ] } } > + > +## > +# @VirtioRingAvail: > +# > +# Information regarding the avail vring (a.k.a. driver area) > +# > +# @flags: VRingAvail flags > +# > +# @idx: VRingAvail index > +# > +# @ring: VRingAvail ring[] entry at provided index > +# > +# Since: 7.0 > +# > +## > + > +{ 'struct': 'VirtioRingAvail', > + 'data': { 'flags': 'uint16', > + 'idx': 'uint16', > + 'ring': 'uint16' } } > + > +## > +# @VirtioRingUsed: > +# > +# Information regarding the used vring (a.k.a. device area) > +# > +# @flags: VRingUsed flags > +# > +# @idx: VRingUsed index > +# > +# Since: 7.0 > +# > +## > + > +{ 'struct': 'VirtioRingUsed', > + 'data': { 'flags': 'uint16', > + 'idx': 'uint16' } } > + > +## > +# @VirtioQueueElement: > +# > +# Information regarding a VirtQueue's VirtQueueElement including > +# descriptor, driver, and device areas > +# > +# @name: Name of the VirtIODevice that uses this VirtQueue > +# > +# @index: Index of the element in the queue > +# > +# @descs: List of descriptors (VirtioRingDesc) > +# > +# @avail: VRingAvail info > +# > +# @used: VRingUsed info > +# > +# Since: 7.0 > +# > +## > + > +{ 'struct': 'VirtioQueueElement', > + 'data': { 'name': 'str', > + 'index': 'uint32', > + 'descs': [ 'VirtioRingDesc' ], > + 'avail': 'VirtioRingAvail', > + 'used': 'VirtioRingUsed' } } > + > +## > +# @x-query-virtio-queue-element: > +# > +# Return the information about a VirtQueue's VirtQueueElement. By > +# default it looks at the head of the queue (if no index is given) > +# > +# @path: VirtIODevice canonical QOM path > +# > +# @queue: VirtQueue index to examine > +# > +# @index: Index of the element in the queue Suggest "(default: head of the queue)", and drop "By default it looks..." above. > +# > +# Features: > +# @unstable: This command is meant for debugging End with a period for consistency with existing docs, like you did in v9. > +# > +# Returns: VirtioQueueElement information > +# > +# Since: 7.0 > +# > +# Examples: > +# > +# 1. Introspect on virtio-net's VirtQueue 0 at index 5 > +# > +# -> { "execute": "x-query-virtio-queue-element", > +# "arguments": { "path": "/machine/peripheral-anon/device[1]/virtio-backend", > +# "queue": 0, > +# "index": 5 } > +# } > +# <- { "return": { > +# "index": 5, > +# "name": "virtio-net", > +# "descs": [ > +# { "flags": ["write"], "len": 1536, "addr": 5257305600 } > +# ], > +# "avail": { > +# "idx": 256, > +# "flags": 0, > +# "ring": 5 > +# }, > +# "used": { > +# "idx": 13, > +# "flags": 0 > +# }, > +# } > +# > +# 2. Introspect on virtio-crypto's VirtQueue 1 at head > +# > +# -> { "execute": "x-query-virtio-queue-element", > +# "arguments": { "path": "/machine/peripheral/crypto0/virtio-backend", > +# "queue": 1 } > +# } > +# <- { "return": { > +# "index": 0, > +# "name": "virtio-crypto", > +# "descs": [ > +# { "flags": [], "len": 0, "addr": 8080268923184214134 } > +# ], > +# "avail": { > +# "idx": 280, > +# "flags": 0, > +# "ring": 0 > +# }, > +# "used": { > +# "idx": 280, > +# "flags": 0 > +# } > +# } > +# > +# 3. Introspect on virtio-scsi's VirtQueue 2 at head > +# > +# -> { "execute": "x-query-virtio-queue-element", > +# "arguments": { "path": "/machine/peripheral-anon/device[2]/virtio-backend", > +# "queue": 2 } > +# } > +# <- { "return": { > +# "index": 19, > +# "name": "virtio-scsi", > +# "descs": [ > +# { "flags": ["used", "indirect", "write"], "len": 4099327944, > +# "addr": 12055409292258155293 } > +# ], > +# "avail": { > +# "idx": 1147, > +# "flags": 0, > +# "ring": 19 > +# }, > +# "used": { > +# "idx": 280, > +# "flags": 0 > +# } > +# } > +# > +## > + > +{ 'command': 'x-query-virtio-queue-element', > + 'data': { 'path': 'str', 'queue': 'uint16', '*index': 'uint16' }, > + 'returns': 'VirtioQueueElement', > + 'features': [ 'unstable' ] } With my doc remarks addressed, QAPI schema Acked-by: Markus Armbruster One more thing: a brief note in the commit messages on why I made you use 'str' instead of enums would be nice.