From: Yongji Xie <xieyongji@bytedance.com> To: Stefan Hajnoczi <stefanha@redhat.com> Cc: "Michael S. Tsirkin" <mst@redhat.com>, "Jason Wang" <jasowang@redhat.com>, "Stefano Garzarella" <sgarzare@redhat.com>, "Parav Pandit" <parav@nvidia.com>, "Christoph Hellwig" <hch@infradead.org>, "Christian Brauner" <christian.brauner@canonical.com>, "Randy Dunlap" <rdunlap@infradead.org>, "Matthew Wilcox" <willy@infradead.org>, "Al Viro" <viro@zeniv.linux.org.uk>, "Jens Axboe" <axboe@kernel.dk>, bcrl@kvack.org, "Jonathan Corbet" <corbet@lwn.net>, "Mika Penttilä" <mika.penttila@nextfour.com>, "Dan Carpenter" <dan.carpenter@oracle.com>, joro@8bytes.org, "Greg KH" <gregkh@linuxfoundation.org>, songmuchun@bytedance.com, virtualization <virtualization@lists.linux-foundation.org>, netdev@vger.kernel.org, kvm <kvm@vger.kernel.org>, linux-fsdevel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-kernel <linux-kernel@vger.kernel.org> Subject: Re: Re: Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace Date: Thu, 1 Jul 2021 14:50:03 +0800 [thread overview] Message-ID: <CACycT3t6M5i0gznABm52v=rdmeeLZu8smXAOLg+WsM3WY1fgTw@mail.gmail.com> (raw) In-Reply-To: <YNw+q/ADMPviZi6S@stefanha-x1.localdomain> On Wed, Jun 30, 2021 at 5:51 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > On Tue, Jun 29, 2021 at 10:59:51AM +0800, Yongji Xie wrote: > > On Mon, Jun 28, 2021 at 9:02 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > On Tue, Jun 15, 2021 at 10:13:30PM +0800, Xie Yongji wrote: > > > > +/* ioctls */ > > > > + > > > > +struct vduse_dev_config { > > > > + char name[VDUSE_NAME_MAX]; /* vduse device name */ > > > > + __u32 vendor_id; /* virtio vendor id */ > > > > + __u32 device_id; /* virtio device id */ > > > > + __u64 features; /* device features */ > > > > + __u64 bounce_size; /* bounce buffer size for iommu */ > > > > + __u16 vq_size_max; /* the max size of virtqueue */ > > > > > > The VIRTIO specification allows per-virtqueue sizes. A device can have > > > two virtqueues, where the first one allows up to 1024 descriptors and > > > the second one allows only 128 descriptors, for example. > > > > > > > Good point! But it looks like virtio-vdpa/virtio-pci doesn't support > > that now. All virtqueues have the same maximum size. > > I see struct vpda_config_ops only supports a per-device max vq size: > u16 (*get_vq_num_max)(struct vdpa_device *vdev); > > virtio-pci supports per-virtqueue sizes because the struct > virtio_pci_common_cfg->queue_size register is per-queue (controlled by > queue_select). > Oh, yes. I miss queue_select. > I guess this is a question for Jason: will vdpa will keep this limitation? > If yes, then VDUSE can stick to it too without running into problems in > the future. > > > > > + __u16 padding; /* padding */ > > > > + __u32 vq_num; /* the number of virtqueues */ > > > > + __u32 vq_align; /* the allocation alignment of virtqueue's metadata */ > > > > > > I'm not sure what this is? > > > > > > > This will be used by vring_create_virtqueue() too. > > If there is no official definition for the meaning of this value then > "/* same as vring_create_virtqueue()'s vring_align parameter */" would > be clearer. That way the reader knows what to research in order to > understand how this field works. > OK. > I don't remember but maybe it was used to support vrings when the > host/guest have non-4KB page sizes. I wonder if anyone has an official > definition for this value? Not sure. Maybe we might need some alignment which is less than PAGE_SIZE sometimes. Thanks, Yongji
WARNING: multiple messages have this Message-ID (diff)
From: Yongji Xie <xieyongji@bytedance.com> To: Stefan Hajnoczi <stefanha@redhat.com> Cc: kvm <kvm@vger.kernel.org>, "Michael S. Tsirkin" <mst@redhat.com>, "Jason Wang" <jasowang@redhat.com>, virtualization <virtualization@lists.linux-foundation.org>, "Christian Brauner" <christian.brauner@canonical.com>, "Jonathan Corbet" <corbet@lwn.net>, "Matthew Wilcox" <willy@infradead.org>, "Christoph Hellwig" <hch@infradead.org>, "Dan Carpenter" <dan.carpenter@oracle.com>, "Stefano Garzarella" <sgarzare@redhat.com>, "Al Viro" <viro@zeniv.linux.org.uk>, songmuchun@bytedance.com, "Jens Axboe" <axboe@kernel.dk>, "Greg KH" <gregkh@linuxfoundation.org>, "Randy Dunlap" <rdunlap@infradead.org>, linux-kernel <linux-kernel@vger.kernel.org>, iommu@lists.linux-foundation.org, bcrl@kvack.org, netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, "Mika Penttilä" <mika.penttila@nextfour.com> Subject: Re: Re: Re: [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace Date: Thu, 1 Jul 2021 14:50:03 +0800 [thread overview] Message-ID: <CACycT3t6M5i0gznABm52v=rdmeeLZu8smXAOLg+WsM3WY1fgTw@mail.gmail.com> (raw) In-Reply-To: <YNw+q/ADMPviZi6S@stefanha-x1.localdomain> On Wed, Jun 30, 2021 at 5:51 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > On Tue, Jun 29, 2021 at 10:59:51AM +0800, Yongji Xie wrote: > > On Mon, Jun 28, 2021 at 9:02 PM Stefan Hajnoczi <stefanha@redhat.com> wrote: > > > > > > On Tue, Jun 15, 2021 at 10:13:30PM +0800, Xie Yongji wrote: > > > > +/* ioctls */ > > > > + > > > > +struct vduse_dev_config { > > > > + char name[VDUSE_NAME_MAX]; /* vduse device name */ > > > > + __u32 vendor_id; /* virtio vendor id */ > > > > + __u32 device_id; /* virtio device id */ > > > > + __u64 features; /* device features */ > > > > + __u64 bounce_size; /* bounce buffer size for iommu */ > > > > + __u16 vq_size_max; /* the max size of virtqueue */ > > > > > > The VIRTIO specification allows per-virtqueue sizes. A device can have > > > two virtqueues, where the first one allows up to 1024 descriptors and > > > the second one allows only 128 descriptors, for example. > > > > > > > Good point! But it looks like virtio-vdpa/virtio-pci doesn't support > > that now. All virtqueues have the same maximum size. > > I see struct vpda_config_ops only supports a per-device max vq size: > u16 (*get_vq_num_max)(struct vdpa_device *vdev); > > virtio-pci supports per-virtqueue sizes because the struct > virtio_pci_common_cfg->queue_size register is per-queue (controlled by > queue_select). > Oh, yes. I miss queue_select. > I guess this is a question for Jason: will vdpa will keep this limitation? > If yes, then VDUSE can stick to it too without running into problems in > the future. > > > > > + __u16 padding; /* padding */ > > > > + __u32 vq_num; /* the number of virtqueues */ > > > > + __u32 vq_align; /* the allocation alignment of virtqueue's metadata */ > > > > > > I'm not sure what this is? > > > > > > > This will be used by vring_create_virtqueue() too. > > If there is no official definition for the meaning of this value then > "/* same as vring_create_virtqueue()'s vring_align parameter */" would > be clearer. That way the reader knows what to research in order to > understand how this field works. > OK. > I don't remember but maybe it was used to support vrings when the > host/guest have non-4KB page sizes. I wonder if anyone has an official > definition for this value? Not sure. Maybe we might need some alignment which is less than PAGE_SIZE sometimes. Thanks, Yongji _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-07-01 6:50 UTC|newest] Thread overview: 193+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-15 14:13 [PATCH v8 00/10] Introduce VDUSE - vDPA Device in Userspace Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 01/10] iova: Export alloc_iova_fast() and free_iova_fast(); Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 02/10] file: Export receive_fd() to modules Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 03/10] eventfd: Increase the recursion depth of eventfd_signal() Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-17 8:33 ` He Zhe 2021-06-17 8:33 ` He Zhe 2021-06-17 8:33 ` He Zhe 2021-06-18 3:29 ` Yongji Xie 2021-06-18 3:29 ` Yongji Xie 2021-06-18 8:41 ` He Zhe 2021-06-18 8:41 ` He Zhe 2021-06-18 8:41 ` He Zhe 2021-06-18 8:44 ` [PATCH] eventfd: Enlarge recursion limit to allow vhost to work He Zhe 2021-06-18 8:44 ` He Zhe 2021-06-18 8:44 ` He Zhe 2021-07-03 8:31 ` Michael S. Tsirkin 2021-07-03 8:31 ` Michael S. Tsirkin 2021-07-03 8:31 ` Michael S. Tsirkin 2021-08-25 7:57 ` Yongji Xie 2021-08-25 7:57 ` Yongji Xie 2021-06-15 14:13 ` [PATCH v8 04/10] vhost-iotlb: Add an opaque pointer for vhost IOTLB Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 05/10] vdpa: Add an opaque pointer for vdpa_config_ops.dma_map() Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 06/10] vdpa: factor out vhost_vdpa_pa_map() and vhost_vdpa_pa_unmap() Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 07/10] vdpa: Support transferring virtual addressing during DMA mapping Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 08/10] vduse: Implement an MMU-based IOMMU driver Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-15 14:13 ` [PATCH v8 09/10] vduse: Introduce VDUSE - vDPA Device in Userspace Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-21 9:13 ` Jason Wang 2021-06-21 9:13 ` Jason Wang 2021-06-21 9:13 ` Jason Wang 2021-06-21 10:41 ` Yongji Xie 2021-06-21 10:41 ` Yongji Xie 2021-06-22 5:06 ` Jason Wang 2021-06-22 5:06 ` Jason Wang 2021-06-22 5:06 ` Jason Wang 2021-06-22 7:22 ` Yongji Xie 2021-06-22 7:22 ` Yongji Xie 2021-06-22 7:49 ` Jason Wang 2021-06-22 7:49 ` Jason Wang 2021-06-22 7:49 ` Jason Wang 2021-06-22 8:14 ` Yongji Xie 2021-06-22 8:14 ` Yongji Xie 2021-06-23 3:30 ` Jason Wang 2021-06-23 3:30 ` Jason Wang 2021-06-23 3:30 ` Jason Wang 2021-06-23 5:50 ` Yongji Xie 2021-06-23 5:50 ` Yongji Xie 2021-06-24 3:34 ` Jason Wang 2021-06-24 3:34 ` Jason Wang 2021-06-24 3:34 ` Jason Wang 2021-06-24 4:46 ` Yongji Xie 2021-06-24 4:46 ` Yongji Xie 2021-06-24 8:13 ` Jason Wang 2021-06-24 8:13 ` Jason Wang 2021-06-24 8:13 ` Jason Wang 2021-06-24 9:16 ` Yongji Xie 2021-06-24 9:16 ` Yongji Xie 2021-06-25 3:08 ` Jason Wang 2021-06-25 3:08 ` Jason Wang 2021-06-25 3:08 ` Jason Wang 2021-06-25 4:19 ` Yongji Xie 2021-06-25 4:19 ` Yongji Xie 2021-06-28 4:40 ` Jason Wang 2021-06-28 4:40 ` Jason Wang 2021-06-28 4:40 ` Jason Wang 2021-06-29 2:26 ` Yongji Xie 2021-06-29 2:26 ` Yongji Xie 2021-06-29 3:29 ` Jason Wang 2021-06-29 3:29 ` Jason Wang 2021-06-29 3:29 ` Jason Wang 2021-06-29 3:56 ` Yongji Xie 2021-06-29 3:56 ` Yongji Xie 2021-06-29 4:03 ` Jason Wang 2021-06-29 4:03 ` Jason Wang 2021-06-29 4:03 ` Jason Wang 2021-06-24 14:46 ` Stefan Hajnoczi 2021-06-24 14:46 ` Stefan Hajnoczi 2021-06-24 14:46 ` Stefan Hajnoczi 2021-06-29 2:59 ` Yongji Xie 2021-06-29 2:59 ` Yongji Xie 2021-06-30 9:51 ` Stefan Hajnoczi 2021-06-30 9:51 ` Stefan Hajnoczi 2021-06-30 9:51 ` Stefan Hajnoczi 2021-07-01 6:50 ` Yongji Xie [this message] 2021-07-01 6:50 ` Yongji Xie 2021-07-01 7:55 ` Jason Wang 2021-07-01 7:55 ` Jason Wang 2021-07-01 7:55 ` Jason Wang 2021-07-01 10:26 ` Yongji Xie 2021-07-01 10:26 ` Yongji Xie 2021-07-02 3:25 ` Jason Wang 2021-07-02 3:25 ` Jason Wang 2021-07-02 3:25 ` Jason Wang 2021-07-07 8:52 ` Stefan Hajnoczi 2021-07-07 8:52 ` Stefan Hajnoczi 2021-07-07 8:52 ` Stefan Hajnoczi 2021-07-07 9:19 ` Yongji Xie 2021-07-07 9:19 ` Yongji Xie 2021-06-15 14:13 ` [PATCH v8 10/10] Documentation: Add documentation for VDUSE Xie Yongji 2021-06-15 14:13 ` Xie Yongji 2021-06-24 13:01 ` Stefan Hajnoczi 2021-06-24 13:01 ` Stefan Hajnoczi 2021-06-24 13:01 ` Stefan Hajnoczi 2021-06-29 5:43 ` Yongji Xie 2021-06-29 5:43 ` Yongji Xie 2021-06-30 10:06 ` Stefan Hajnoczi 2021-06-30 10:06 ` Stefan Hajnoczi 2021-06-30 10:06 ` Stefan Hajnoczi 2021-07-01 10:00 ` Yongji Xie 2021-07-01 10:00 ` Yongji Xie 2021-07-01 13:15 ` Stefan Hajnoczi 2021-07-01 13:15 ` Stefan Hajnoczi 2021-07-01 13:15 ` Stefan Hajnoczi 2021-07-04 9:49 ` Yongji Xie 2021-07-04 9:49 ` Yongji Xie 2021-07-05 3:36 ` Jason Wang 2021-07-05 3:36 ` Jason Wang 2021-07-05 3:36 ` Jason Wang 2021-07-05 12:49 ` Stefan Hajnoczi 2021-07-05 12:49 ` Stefan Hajnoczi 2021-07-05 12:49 ` Stefan Hajnoczi 2021-07-06 2:34 ` Jason Wang 2021-07-06 2:34 ` Jason Wang 2021-07-06 2:34 ` Jason Wang 2021-07-06 10:14 ` Stefan Hajnoczi 2021-07-06 10:14 ` Stefan Hajnoczi 2021-07-06 10:14 ` Stefan Hajnoczi [not found] ` <CACGkMEs2HHbUfarum8uQ6wuXoDwLQUSXTsa-huJFiqr__4cwRg@mail.gmail.com> [not found] ` <YOSOsrQWySr0andk@stefanha-x1.localdomain> [not found] ` <100e6788-7fdf-1505-d69c-bc28a8bc7a78@redhat.com> [not found] ` <YOVr801d01YOPzLL@stefanha-x1.localdomain> 2021-07-07 9:24 ` Jason Wang 2021-07-07 9:24 ` Jason Wang 2021-07-07 9:24 ` Jason Wang 2021-07-07 15:54 ` Stefan Hajnoczi 2021-07-07 15:54 ` Stefan Hajnoczi 2021-07-07 15:54 ` Stefan Hajnoczi 2021-07-08 4:17 ` Jason Wang 2021-07-08 4:17 ` Jason Wang 2021-07-08 4:17 ` Jason Wang 2021-07-08 9:06 ` Stefan Hajnoczi 2021-07-08 9:06 ` Stefan Hajnoczi 2021-07-08 9:06 ` Stefan Hajnoczi 2021-07-08 12:35 ` Yongji Xie 2021-07-08 12:35 ` Yongji Xie 2021-07-06 3:04 ` Yongji Xie 2021-07-06 3:04 ` Yongji Xie 2021-07-06 10:22 ` Stefan Hajnoczi 2021-07-06 10:22 ` Stefan Hajnoczi 2021-07-06 10:22 ` Stefan Hajnoczi 2021-07-07 9:09 ` Yongji Xie 2021-07-07 9:09 ` Yongji Xie 2021-07-08 9:07 ` Stefan Hajnoczi 2021-07-08 9:07 ` Stefan Hajnoczi 2021-07-08 9:07 ` Stefan Hajnoczi 2021-06-24 15:12 ` [PATCH v8 00/10] Introduce VDUSE - vDPA Device in Userspace Stefan Hajnoczi 2021-06-24 15:12 ` Stefan Hajnoczi 2021-06-24 15:12 ` Stefan Hajnoczi 2021-06-29 3:15 ` Yongji Xie 2021-06-29 3:15 ` Yongji Xie 2021-06-28 10:33 ` Liu Xiaodong 2021-06-28 10:33 ` Liu Xiaodong 2021-06-28 10:33 ` Liu Xiaodong 2021-06-28 4:35 ` Jason Wang 2021-06-28 4:35 ` Jason Wang 2021-06-28 4:35 ` Jason Wang 2021-06-28 5:54 ` Liu, Xiaodong 2021-06-28 5:54 ` Liu, Xiaodong 2021-06-28 5:54 ` Liu, Xiaodong 2021-06-29 4:10 ` Jason Wang 2021-06-29 4:10 ` Jason Wang 2021-06-29 4:10 ` Jason Wang 2021-06-29 7:56 ` Liu, Xiaodong 2021-06-29 7:56 ` Liu, Xiaodong 2021-06-29 7:56 ` Liu, Xiaodong 2021-06-29 8:14 ` Yongji Xie 2021-06-29 8:14 ` Yongji Xie 2021-06-28 10:32 ` Yongji Xie 2021-06-28 10:32 ` Yongji Xie 2021-06-28 10:32 ` Yongji Xie 2021-06-29 4:12 ` Jason Wang 2021-06-29 4:12 ` Jason Wang 2021-06-29 4:12 ` Jason Wang 2021-06-29 6:40 ` Yongji Xie 2021-06-29 6:40 ` Yongji Xie 2021-06-29 7:33 ` Jason Wang 2021-06-29 7:33 ` Jason Wang 2021-06-29 7:33 ` Jason Wang
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