From: Jason Wang <jasowang@redhat.com> To: Jason Gunthorpe <jgg@nvidia.com> Cc: mst <mst@redhat.com>, linux-kernel <linux-kernel@vger.kernel.org>, kvm <kvm@vger.kernel.org>, virtualization <virtualization@lists.linux-foundation.org>, netdev <netdev@vger.kernel.org>, Maxime Coquelin <maxime.coquelin@redhat.com>, "Liang, Cunming" <cunming.liang@intel.com>, zhihong.wang@intel.com, rob.miller@broadcom.com, Xiao W Wang <xiao.w.wang@intel.com>, Zhu Lingshan <lingshan.zhu@intel.com>, eperezma <eperezma@redhat.com>, Cindy Lu <lulu@redhat.com>, Parav Pandit <parav@mellanox.com>, "Tian, Kevin" <kevin.tian@intel.com>, Stefan Hajnoczi <stefanha@redhat.com>, Randy Dunlap <rdunlap@infradead.org>, Christoph Hellwig <hch@infradead.org>, Ariel Adam <aadam@redhat.com>, jiri@mellanox.com, shahafs@mellanox.com, Harpreet Singh Anand <hanand@xilinx.com>, mhabets@solarflare.com, Gautam Dawar <gdawar@xilinx.com>, Saugat Mitra <saugatm@xilinx.com>, vmireyno@marvell.com, zhangweining@ruijie.com.cn, Tiwei Bie <tiwei.bie@intel.com>, Lu Baolu <baolu.lu@linux.intel.com> Subject: Re: [PATCH V9 7/9] vhost: introduce vDPA-based backend Date: Tue, 2 Nov 2021 11:52:20 +0800 [thread overview] Message-ID: <CACGkMEtbs3u7J7krpkusfqczTU00+6o_YtZjD8htC=+Un9cNew@mail.gmail.com> (raw) In-Reply-To: <20211101141133.GA1073864@nvidia.com> On Mon, Nov 1, 2021 at 10:11 PM Jason Gunthorpe <jgg@nvidia.com> wrote: > > On Thu, Mar 26, 2020 at 10:01:23PM +0800, Jason Wang wrote: > > From: Tiwei Bie <tiwei.bie@intel.com> > > > > This patch introduces a vDPA-based vhost backend. This backend is > > built on top of the same interface defined in virtio-vDPA and provides > > a generic vhost interface for userspace to accelerate the virtio > > devices in guest. > > > > This backend is implemented as a vDPA device driver on top of the same > > ops used in virtio-vDPA. It will create char device entry named > > vhost-vdpa-$index for userspace to use. Userspace can use vhost ioctls > > on top of this char device to setup the backend. > > > > Vhost ioctls are extended to make it type agnostic and behave like a > > virtio device, this help to eliminate type specific API like what > > vhost_net/scsi/vsock did: > > > > - VHOST_VDPA_GET_DEVICE_ID: get the virtio device ID which is defined > > by virtio specification to differ from different type of devices > > - VHOST_VDPA_GET_VRING_NUM: get the maximum size of virtqueue > > supported by the vDPA device > > - VHSOT_VDPA_SET/GET_STATUS: set and get virtio status of vDPA device > > - VHOST_VDPA_SET/GET_CONFIG: access virtio config space > > - VHOST_VDPA_SET_VRING_ENABLE: enable a specific virtqueue > > > > For memory mapping, IOTLB API is mandated for vhost-vDPA which means > > userspace drivers are required to use > > VHOST_IOTLB_UPDATE/VHOST_IOTLB_INVALIDATE to add or remove mapping for > > a specific userspace memory region. > > > > The vhost-vDPA API is designed to be type agnostic, but it allows net > > device only in current stage. Due to the lacking of control virtqueue > > support, some features were filter out by vhost-vdpa. > > > > We will enable more features and devices in the near future. > > [..] > > > +static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v) > > +{ > > + struct vdpa_device *vdpa = v->vdpa; > > + const struct vdpa_config_ops *ops = vdpa->config; > > + struct device *dma_dev = vdpa_get_dma_dev(vdpa); > > + struct bus_type *bus; > > + int ret; > > + > > + /* Device want to do DMA by itself */ > > + if (ops->set_map || ops->dma_map) > > + return 0; > > + > > + bus = dma_dev->bus; > > + if (!bus) > > + return -EFAULT; > > + > > + if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY)) > > + return -ENOTSUPP; > > + > > + v->domain = iommu_domain_alloc(bus); > > + if (!v->domain) > > + return -EIO; > > + > > + ret = iommu_attach_device(v->domain, dma_dev); > > + if (ret) > > + goto err_attach; > > > > I've been looking at the security of iommu_attach_device() users, and > I wonder if this is safe? > > The security question is if userspace is able to control the DMA > address the devices uses? Eg if any of the cpu to device ring's are in > userspace memory? > > For instance if userspace can tell the device to send a packet from an > arbitrary user controlled address. The map is validated via pin_user_pages() which guarantees that the address is not arbitrary and must belong to userspace? Thanks > > Thanks, > Jason >
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com> To: Jason Gunthorpe <jgg@nvidia.com> Cc: kvm <kvm@vger.kernel.org>, mst <mst@redhat.com>, mhabets@solarflare.com, virtualization <virtualization@lists.linux-foundation.org>, rob.miller@broadcom.com, Saugat Mitra <saugatm@xilinx.com>, Cindy Lu <lulu@redhat.com>, Harpreet Singh Anand <hanand@xilinx.com>, Christoph Hellwig <hch@infradead.org>, eperezma <eperezma@redhat.com>, shahafs@mellanox.com, Parav Pandit <parav@mellanox.com>, vmireyno@marvell.com, Gautam Dawar <gdawar@xilinx.com>, jiri@mellanox.com, Xiao W Wang <xiao.w.wang@intel.com>, Stefan Hajnoczi <stefanha@redhat.com>, zhihong.wang@intel.com, zhangweining@ruijie.com.cn, Tiwei Bie <tiwei.bie@intel.com>, Randy Dunlap <rdunlap@infradead.org>, linux-kernel <linux-kernel@vger.kernel.org>, Maxime Coquelin <maxime.coquelin@redhat.com>, netdev <netdev@vger.kernel.org>, Zhu Lingshan <lingshan.zhu@intel.com>, Lu Baolu <baolu.lu@linux.intel.com> Subject: Re: [PATCH V9 7/9] vhost: introduce vDPA-based backend Date: Tue, 2 Nov 2021 11:52:20 +0800 [thread overview] Message-ID: <CACGkMEtbs3u7J7krpkusfqczTU00+6o_YtZjD8htC=+Un9cNew@mail.gmail.com> (raw) In-Reply-To: <20211101141133.GA1073864@nvidia.com> On Mon, Nov 1, 2021 at 10:11 PM Jason Gunthorpe <jgg@nvidia.com> wrote: > > On Thu, Mar 26, 2020 at 10:01:23PM +0800, Jason Wang wrote: > > From: Tiwei Bie <tiwei.bie@intel.com> > > > > This patch introduces a vDPA-based vhost backend. This backend is > > built on top of the same interface defined in virtio-vDPA and provides > > a generic vhost interface for userspace to accelerate the virtio > > devices in guest. > > > > This backend is implemented as a vDPA device driver on top of the same > > ops used in virtio-vDPA. It will create char device entry named > > vhost-vdpa-$index for userspace to use. Userspace can use vhost ioctls > > on top of this char device to setup the backend. > > > > Vhost ioctls are extended to make it type agnostic and behave like a > > virtio device, this help to eliminate type specific API like what > > vhost_net/scsi/vsock did: > > > > - VHOST_VDPA_GET_DEVICE_ID: get the virtio device ID which is defined > > by virtio specification to differ from different type of devices > > - VHOST_VDPA_GET_VRING_NUM: get the maximum size of virtqueue > > supported by the vDPA device > > - VHSOT_VDPA_SET/GET_STATUS: set and get virtio status of vDPA device > > - VHOST_VDPA_SET/GET_CONFIG: access virtio config space > > - VHOST_VDPA_SET_VRING_ENABLE: enable a specific virtqueue > > > > For memory mapping, IOTLB API is mandated for vhost-vDPA which means > > userspace drivers are required to use > > VHOST_IOTLB_UPDATE/VHOST_IOTLB_INVALIDATE to add or remove mapping for > > a specific userspace memory region. > > > > The vhost-vDPA API is designed to be type agnostic, but it allows net > > device only in current stage. Due to the lacking of control virtqueue > > support, some features were filter out by vhost-vdpa. > > > > We will enable more features and devices in the near future. > > [..] > > > +static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v) > > +{ > > + struct vdpa_device *vdpa = v->vdpa; > > + const struct vdpa_config_ops *ops = vdpa->config; > > + struct device *dma_dev = vdpa_get_dma_dev(vdpa); > > + struct bus_type *bus; > > + int ret; > > + > > + /* Device want to do DMA by itself */ > > + if (ops->set_map || ops->dma_map) > > + return 0; > > + > > + bus = dma_dev->bus; > > + if (!bus) > > + return -EFAULT; > > + > > + if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY)) > > + return -ENOTSUPP; > > + > > + v->domain = iommu_domain_alloc(bus); > > + if (!v->domain) > > + return -EIO; > > + > > + ret = iommu_attach_device(v->domain, dma_dev); > > + if (ret) > > + goto err_attach; > > > > I've been looking at the security of iommu_attach_device() users, and > I wonder if this is safe? > > The security question is if userspace is able to control the DMA > address the devices uses? Eg if any of the cpu to device ring's are in > userspace memory? > > For instance if userspace can tell the device to send a packet from an > arbitrary user controlled address. The map is validated via pin_user_pages() which guarantees that the address is not arbitrary and must belong to userspace? Thanks > > Thanks, > Jason > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2021-11-02 3:52 UTC|newest] Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-03-26 14:01 [PATCH V9 0/9] vDPA support Jason Wang 2020-03-26 14:01 ` [PATCH V9 1/9] vhost: refine vhost and vringh kconfig Jason Wang 2020-04-01 11:21 ` Christian Borntraeger 2020-04-01 12:50 ` Jason Wang 2020-04-01 12:56 ` Christian Borntraeger 2020-04-01 13:02 ` Christian Borntraeger 2020-04-01 14:01 ` Michael S. Tsirkin 2020-04-01 14:13 ` Jason Wang 2020-04-01 14:18 ` Michael S. Tsirkin 2020-04-01 14:36 ` Jason Wang 2020-04-01 14:27 ` Michael S. Tsirkin 2020-04-01 14:50 ` Jason Wang 2020-04-01 15:57 ` Michael S. Tsirkin 2020-04-01 18:53 ` Christian Borntraeger 2020-04-01 13:22 ` Michael S. Tsirkin 2020-04-01 14:08 ` Jason Wang 2020-04-01 14:13 ` Michael S. Tsirkin 2020-04-01 14:29 ` Jason Wang 2020-04-01 14:35 ` Michael S. Tsirkin 2020-04-01 14:39 ` Jason Wang 2020-04-01 14:39 ` Michael S. Tsirkin 2020-04-01 14:43 ` Jason Wang 2020-04-01 16:05 ` Michael S. Tsirkin 2020-04-01 16:08 ` Michael S. Tsirkin 2020-04-02 3:22 ` Jason Wang 2020-04-02 3:22 ` Jason Wang 2020-04-02 14:03 ` Michael S. Tsirkin 2020-04-02 14:23 ` Jason Wang 2020-04-02 14:38 ` Michael S. Tsirkin 2020-04-02 14:56 ` Jason Wang 2020-03-26 14:01 ` [PATCH V9 2/9] vhost: allow per device message handler Jason Wang 2020-03-26 14:01 ` [PATCH V9 3/9] vhost: factor out IOTLB Jason Wang 2020-03-26 14:01 ` [PATCH V9 4/9] vringh: IOTLB support Jason Wang 2020-03-26 14:01 ` [PATCH V9 5/9] vDPA: introduce vDPA bus Jason Wang 2020-03-26 14:01 ` [PATCH V9 6/9] virtio: introduce a vDPA based transport Jason Wang 2020-03-26 14:01 ` [PATCH V9 7/9] vhost: introduce vDPA-based backend Jason Wang 2021-11-01 14:11 ` Jason Gunthorpe 2021-11-02 3:52 ` Jason Wang [this message] 2021-11-02 3:52 ` Jason Wang 2021-11-02 15:56 ` Jason Gunthorpe 2021-11-03 7:34 ` Jason Wang 2021-11-03 7:34 ` Jason Wang 2020-03-26 14:01 ` [PATCH V9 8/9] vdpasim: vDPA device simulator Jason Wang 2020-04-10 7:45 ` Geert Uytterhoeven 2020-04-10 7:45 ` Geert Uytterhoeven 2020-04-10 8:23 ` Jason Wang 2020-04-10 8:23 ` Jason Wang 2020-03-26 14:01 ` [PATCH V9 9/9] virtio: Intel IFC VF driver for VDPA Jason Wang 2020-04-09 10:41 ` Arnd Bergmann 2020-04-09 10:41 ` Arnd Bergmann 2020-04-09 12:43 ` Jason Wang 2020-04-09 12:43 ` Jason Wang 2020-04-09 12:49 ` Zhu, Lingshan 2020-04-09 12:49 ` Zhu, Lingshan 2020-04-09 20:25 ` Michael S. Tsirkin 2020-04-09 20:25 ` Michael S. Tsirkin 2020-04-10 3:15 ` Zhu, Lingshan 2020-04-10 3:15 ` Zhu, Lingshan 2020-03-29 11:07 ` [PATCH V9 0/9] vDPA support Michael S. Tsirkin
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