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 203A0C433EF for ; Wed, 19 Jan 2022 17:19:50 +0000 (UTC) Received: from localhost ([::1]:42794 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nAEcf-0002ss-0U for qemu-devel@archiver.kernel.org; Wed, 19 Jan 2022 12:19:49 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43316) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nAEZ2-0000no-Dc for qemu-devel@nongnu.org; Wed, 19 Jan 2022 12:16:04 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:59784) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nAEYv-0008C8-Pr for qemu-devel@nongnu.org; Wed, 19 Jan 2022 12:16:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1642612555; 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=nXXOJUHaN54LlsfNUYhZM4coUBB6GNMO3fXCPYuWDNQ=; b=du40S1maLyZUFl2op8nvEq6fJgNvqRVJAn5MpMLmbRVT/8Uv/W0jAaAdFojCUru7TP9t48 5BTcTz/eCC4wNtF5Q4jJcrOCf8TI4bRzd22nHW3npZClkKaLeAxao8nWEIX857bd4fPK6a pjIl1IKGtHK98uYTkZndNJ2CpsrI44A= 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-665-QP7OodXlPHaNrITc0PPp6Q-1; Wed, 19 Jan 2022 12:15:54 -0500 X-MC-Unique: QP7OodXlPHaNrITc0PPp6Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A4E794686E; Wed, 19 Jan 2022 17:15:47 +0000 (UTC) Received: from localhost (unknown [10.39.192.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2295C798DA; Wed, 19 Jan 2022 17:15:46 +0000 (UTC) Date: Wed, 19 Jan 2022 17:15:46 +0000 From: Stefan Hajnoczi To: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" Subject: Re: [RFC 05/10] vdpa-dev: implement the realize interface Message-ID: References: <20220105005900.860-1-longpeng2@huawei.com> <20220105005900.860-6-longpeng2@huawei.com> <8abbe9c2599247599aec2d0d7ff01c32@huawei.com> <99584ad9258745e1a9d1ba2e7ee4239d@huawei.com> MIME-Version: 1.0 In-Reply-To: <99584ad9258745e1a9d1ba2e7ee4239d@huawei.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cTtuV5cpj1NUmZYL" Content-Disposition: inline Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.7, 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" , "jasowang@redhat.com" , "cohuck@redhat.com" , "qemu-devel@nongnu.org" , Yechuan , "Gonglei \(Arei\)" , Huangzhichao , "pbonzini@redhat.com" , "sgarzare@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --cTtuV5cpj1NUmZYL Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jan 17, 2022 at 12:34:50PM +0000, Longpeng (Mike, Cloud Infrastruct= ure Service Product Dept.) wrote: >=20 >=20 > > -----Original Message----- > > From: Stefan Hajnoczi [mailto:stefanha@redhat.com] > > Sent: Thursday, January 6, 2022 7:34 PM > > To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.) > > > > Cc: mst@redhat.com; jasowang@redhat.com; sgarzare@redhat.com; > > cohuck@redhat.com; pbonzini@redhat.com; Gonglei (Arei) > > ; Yechuan ; Huangzhichao > > ; qemu-devel@nongnu.org > > Subject: Re: [RFC 05/10] vdpa-dev: implement the realize interface > >=20 > > On Thu, Jan 06, 2022 at 03:02:37AM +0000, Longpeng (Mike, Cloud Infrast= ructure > > Service Product Dept.) wrote: > > > > > > > > > > -----Original Message----- > > > > From: Stefan Hajnoczi [mailto:stefanha@redhat.com] > > > > Sent: Wednesday, January 5, 2022 6:18 PM > > > > To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.) > > > > > > > > Cc: mst@redhat.com; jasowang@redhat.com; sgarzare@redhat.com; > > > > cohuck@redhat.com; pbonzini@redhat.com; Gonglei (Arei) > > > > ; Yechuan ; Huangzhich= ao > > > > ; qemu-devel@nongnu.org > > > > Subject: Re: [RFC 05/10] vdpa-dev: implement the realize interface > > > > > > > > On Wed, Jan 05, 2022 at 08:58:55AM +0800, Longpeng(Mike) wrote: > > > > > From: Longpeng > > > > > > > > > > Implements the .realize interface. > > > > > > > > > > Signed-off-by: Longpeng > > > > > --- > > > > > hw/virtio/vdpa-dev.c | 114 +++++++++++++++++++++++++++++= ++++++ > > > > > include/hw/virtio/vdpa-dev.h | 8 +++ > > > > > 2 files changed, 122 insertions(+) > > > > > > > > > > diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c > > > > > index 790117fb3b..2d534d837a 100644 > > > > > --- a/hw/virtio/vdpa-dev.c > > > > > +++ b/hw/virtio/vdpa-dev.c > > > > > @@ -15,9 +15,122 @@ > > > > > #include "sysemu/sysemu.h" > > > > > #include "sysemu/runstate.h" > > > > > > > > > > +static void > > > > > +vhost_vdpa_device_dummy_handle_output(VirtIODevice *vdev, VirtQu= eue > > *vq) > > > > > +{ > > > > > + /* Nothing to do */ > > > > > +} > > > > > + > > > > > +static int vdpa_dev_get_info_by_fd(int fd, uint64_t cmd, Error *= *errp) > > > > > > > > This looks similar to the helper function in a previous patch but t= his > > > > time the return value type is int instead of uint32_t. Please make = the > > > > types consistent. > > > > > > > > > > OK. > > > > > > > > +{ > > > > > + int val; > > > > > + > > > > > + if (ioctl(fd, cmd, &val) < 0) { > > > > > + error_setg(errp, "vhost-vdpa-device: cmd 0x%lx failed: %= s", > > > > > + cmd, strerror(errno)); > > > > > + return -1; > > > > > + } > > > > > + > > > > > + return val; > > > > > +} > > > > > + > > > > > +static inline int vdpa_dev_get_queue_size(int fd, Error **errp) > > > > > +{ > > > > > + return vdpa_dev_get_info_by_fd(fd, VHOST_VDPA_GET_VRING_NUM,= errp); > > > > > +} > > > > > + > > > > > +static inline int vdpa_dev_get_vqs_num(int fd, Error **errp) > > > > > +{ > > > > > + return vdpa_dev_get_info_by_fd(fd, VHOST_VDPA_GET_VQS_NUM, e= rrp); > > > > > +} > > > > > + > > > > > +static inline int vdpa_dev_get_config_size(int fd, Error **errp) > > > > > +{ > > > > > + return vdpa_dev_get_info_by_fd(fd, VHOST_VDPA_GET_CONFIG_SIZ= E, > > errp); > > > > > +} > > > > > + > > > > > static void vhost_vdpa_device_realize(DeviceState *dev, Error **= errp) > > > > > { > > > > > + VirtIODevice *vdev =3D VIRTIO_DEVICE(dev); > > > > > + VhostVdpaDevice *s =3D VHOST_VDPA_DEVICE(vdev); > > > > > + uint32_t device_id; > > > > > + int max_queue_size; > > > > > + int fd; > > > > > + int i, ret; > > > > > + > > > > > + fd =3D qemu_open(s->vdpa_dev, O_RDWR, errp); > > > > > + if (fd =3D=3D -1) { > > > > > + return; > > > > > + } > > > > > + s->vdpa.device_fd =3D fd; > > > > > > > > This is the field I suggest exposing as a QOM property so it can be= set > > > > from the proxy object (e.g. when the PCI proxy opens the vdpa devic= e > > > > before our .realize() function is called). > > > > > > > > > > OK. > > > > > > > > + > > > > > + max_queue_size =3D vdpa_dev_get_queue_size(fd, errp); > > > > > + if (*errp) { > > > > > + goto out; > > > > > + } > > > > > + > > > > > + if (s->queue_size > max_queue_size) { > > > > > + error_setg(errp, "vhost-vdpa-device: invalid queue_size:= %d > > > > (max:%d)", > > > > > + s->queue_size, max_queue_size); > > > > > + goto out; > > > > > + } else if (!s->queue_size) { > > > > > + s->queue_size =3D max_queue_size; > > > > > + } > > > > > + > > > > > + ret =3D vdpa_dev_get_vqs_num(fd, errp); > > > > > + if (*errp) { > > > > > + goto out; > > > > > + } > > > > > + > > > > > + s->dev.nvqs =3D ret; > > > > > > > > There is no input validation because we trust the kernel vDPA retur= n > > > > values. That seems okay for now but if there is a vhost-user versio= n of > > > > this in the future then input validation will be necessary to achie= ve > > > > isolation between QEMU and the vhost-user processes. I suggest incl= uding > > > > input validation code right away because it's harder to audit the c= ode > > > > and fix missing input validation later on. > > > > > > > > > > Make sense! > > > > > > Should we only need to validate the upper boundary (e.g. >=20 > > Careful, ret is currently an int so negative values would bypass the < > > VIRTIO_QUEUE_MAX check. > >=20 > > > > > > > > + s->dev.vqs =3D g_new0(struct vhost_virtqueue, s->dev.nvqs); > > > > > + s->dev.vq_index =3D 0; > > > > > + s->dev.vq_index_end =3D s->dev.nvqs; > > > > > + s->dev.backend_features =3D 0; > > > > > + s->started =3D false; > > > > > + > > > > > + ret =3D vhost_dev_init(&s->dev, &s->vdpa, VHOST_BACKEND_TYPE= _VDPA, 0, > > > > NULL); > > > > > + if (ret < 0) { > > > > > + error_setg(errp, "vhost-vdpa-device: vhost initializatio= n > > > > failed: %s", > > > > > + strerror(-ret)); > > > > > + goto out; > > > > > + } > > > > > + > > > > > + ret =3D s->dev.vhost_ops->vhost_get_device_id(&s->dev, &devi= ce_id); > > > > > > > > The vhost_*() API abstracts the ioctl calls but this source file an= d the > > > > PCI proxy have ioctl calls. I wonder if it's possible to move the i= octls > > > > calls into the vhost_*() API? That would be cleaner and also make i= t > > > > easier to add vhost-user vDPA support in the future. > > > > > > We need these ioctls calls because we need invoke them before the vho= st-dev > > > object is initialized. > >=20 > > It may be possible to clean this up by changing how vhost_dev_init() > > works but I haven't investigated. The issue is that the vhost_dev_init(= ) > > API requires information from the caller that has to be fetched from th= e > > vDPA device. This forces the caller to communicate directly with the > > vDPA device before calling vhost_dev_init(). It may be possible to move > > this setup code inside vhost_dev_init() (and vhost_ops callbacks). > >=20 >=20 > Hmm, this is still not clear to me, so let's continue to discuss this > in v2 if you think it's necessary. Okay. 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