Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
On Thu, Sep 14, 2023 at 6:56 PM Akihiko Odaki wrote: > On 2023/09/14 17:29, Albert Esteve wrote: > > > > > > On Thu, Sep 14, 2023 at 9:17 AM Akihiko Odaki > <mailto:akihiko.od...@daynix.com>> wrote: > > > > On 2023/09/13 23:18, Albert Esteve wrote: > > > > > > > > > On Wed, Sep 13, 2023 at 3:43 PM Akihiko Odaki > > mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>> wrote: > > > > > > On 2023/09/13 21:58, Albert Esteve wrote: > > > > > > > > > > > > On Wed, Sep 13, 2023 at 2:22 PM Akihiko Odaki > > > mailto:akihiko.od...@daynix.com> > > <mailto:akihiko.od...@daynix.com <mailto:akihiko.od...@daynix.com>> > > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>>> wrote: > > > > > > > > On 2023/09/13 20:34, Albert Esteve wrote: > > > > > > > > > > > > > > > On Wed, Sep 13, 2023 at 12:34 PM Akihiko Odaki > > > > > <mailto:akihiko.od...@daynix.com> <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com> <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>> > > > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>> > > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>>>> wrote: > > > > > > > > > > On 2023/09/13 16:55, Albert Esteve wrote: > > > > > > Hi Antonio, > > > > > > > > > > > > If I'm not mistaken, this patch is related > with: > > > > > > > > > > > > > > > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>>> > > > > > > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>>>> > > > > > > > > > > > > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < &g
Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
On Thu, Sep 14, 2023 at 9:17 AM Akihiko Odaki wrote: > On 2023/09/13 23:18, Albert Esteve wrote: > > > > > > On Wed, Sep 13, 2023 at 3:43 PM Akihiko Odaki > <mailto:akihiko.od...@daynix.com>> wrote: > > > > On 2023/09/13 21:58, Albert Esteve wrote: > > > > > > > > > On Wed, Sep 13, 2023 at 2:22 PM Akihiko Odaki > > mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>> wrote: > > > > > > On 2023/09/13 20:34, Albert Esteve wrote: > > > > > > > > > > > > On Wed, Sep 13, 2023 at 12:34 PM Akihiko Odaki > > > mailto:akihiko.od...@daynix.com> > > <mailto:akihiko.od...@daynix.com <mailto:akihiko.od...@daynix.com>> > > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>>> wrote: > > > > > > > > On 2023/09/13 16:55, Albert Esteve wrote: > > > > > Hi Antonio, > > > > > > > > > > If I'm not mistaken, this patch is related with: > > > > > > > > > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>>> > > > > > > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>>>> > > > > > IMHO, ideally, virtio-gpu and vhost-user-gpu both, > > would > > > use the > > > > > infrastructure from the patch I linked to store the > > > > > virtio objects, so that they can be later shared > with > > > other devices. > > > > > > > > I don't think such sharing is possible because the > > resources are > > > > identified by IDs that are local to the device. That > also > > > complicates > > > > migration. > > > > > > > > Regards, > > > > Akihiko Odaki > > > > > > > > Hi Akihiko, > > > > > > > > As far as I understand, the feature to export > > dma-bufs from the > > > > virtgpu was introduced as part of the virtio cross-device > > sharing > > > > proposal [1]. Thus, it shall be posible. When > > virtgpu ASSING_UUID, > > > > it exports and identifies the dmabuf resource, so that > > when the > > > dmabuf gets > > > > shared inside the guest (e.g., with virtio-video), we can > > use the > > > assigned > > > > UUID to find the dmabuf in the host (using the patch that I > > > linked above), > > > > and import it. > > > > > > > > [1] - https://lwn.net/Articl
Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
On Wed, Sep 13, 2023 at 4:18 PM Albert Esteve wrote: > > > On Wed, Sep 13, 2023 at 3:43 PM Akihiko Odaki > wrote: > >> On 2023/09/13 21:58, Albert Esteve wrote: >> > >> > >> > On Wed, Sep 13, 2023 at 2:22 PM Akihiko Odaki > > <mailto:akihiko.od...@daynix.com>> wrote: >> > >> > On 2023/09/13 20:34, Albert Esteve wrote: >> > > >> > > >> > > On Wed, Sep 13, 2023 at 12:34 PM Akihiko Odaki >> > mailto:akihiko.od...@daynix.com> >> > > <mailto:akihiko.od...@daynix.com >> > <mailto:akihiko.od...@daynix.com>>> wrote: >> > > >> > > On 2023/09/13 16:55, Albert Esteve wrote: >> > > > Hi Antonio, >> > > > >> > > > If I'm not mistaken, this patch is related with: >> > > > >> > > >> > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html >> > < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> >> > > >> > < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> >> > > > >> > > >> > < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> >> > > >> > < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < >> https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>>> >> > > > IMHO, ideally, virtio-gpu and vhost-user-gpu both, would >> > use the >> > > > infrastructure from the patch I linked to store the >> > > > virtio objects, so that they can be later shared with >> > other devices. >> > > >> > > I don't think such sharing is possible because the resources >> are >> > > identified by IDs that are local to the device. That also >> > complicates >> > > migration. >> > > >> > > Regards, >> > > Akihiko Odaki >> > > >> > > Hi Akihiko, >> > > >> > > As far as I understand, the feature to export dma-bufs from the >> > > virtgpu was introduced as part of the virtio cross-device sharing >> > > proposal [1]. Thus, it shall be posible. When >> virtgpu ASSING_UUID, >> > > it exports and identifies the dmabuf resource, so that when the >> > dmabuf gets >> > > shared inside the guest (e.g., with virtio-video), we can use the >> > assigned >> > > UUID to find the dmabuf in the host (using the patch that I >> > linked above), >> > > and import it. >> > > >> > > [1] - https://lwn.net/Articles/828988/ >> > <https://lwn.net/Articles/828988/> < >> https://lwn.net/Articles/828988/ >> > <https://lwn.net/Articles/828988/>> >> > >> > The problem is that virtio-gpu can have other kind of resources like >> > pixman and OpenGL textures and manage them and DMA-BUFs with unified >> > resource ID. >> > >> > >> > I see. >> > >> > >> > So you cannot change: >> > g_hash_table_insert(g->resource_uuids, >> > GUINT_TO_POINTER(assign.resource_id), uuid); >> > by: >> > virtio_add_dmabuf(uuid, assign.resource_id); >> > >> > assign.resource_id is not DMA-BUF file descriptor, and the >> underlying >> > resource my not be DMA-BUF at first place. >> > >> > >> > I didn't really look into the patch in-depth, so the code was intended >> > to give an idea of how the implementation would look like with >> > the cross-device patch API. Indeed, it is not the resource_id, >> > (I just took a brief look at the virtio specificacion 1.2), but the >> > underlying >> > resource what we want to use here. >> > >> > >> > Also, since this lives in the common code that is not used only by >> > virtio-gpu-gl but also virtio-gpu, which supports migration, we also >> > need to t
Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
On Wed, Sep 13, 2023 at 3:43 PM Akihiko Odaki wrote: > On 2023/09/13 21:58, Albert Esteve wrote: > > > > > > On Wed, Sep 13, 2023 at 2:22 PM Akihiko Odaki > <mailto:akihiko.od...@daynix.com>> wrote: > > > > On 2023/09/13 20:34, Albert Esteve wrote: > > > > > > > > > On Wed, Sep 13, 2023 at 12:34 PM Akihiko Odaki > > mailto:akihiko.od...@daynix.com> > > > <mailto:akihiko.od...@daynix.com > > <mailto:akihiko.od...@daynix.com>>> wrote: > > > > > > On 2023/09/13 16:55, Albert Esteve wrote: > > > > Hi Antonio, > > > > > > > > If I'm not mistaken, this patch is related with: > > > > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>> > > > > > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> > > > > > < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html < > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html>>> > > > > IMHO, ideally, virtio-gpu and vhost-user-gpu both, would > > use the > > > > infrastructure from the patch I linked to store the > > > > virtio objects, so that they can be later shared with > > other devices. > > > > > > I don't think such sharing is possible because the resources > are > > > identified by IDs that are local to the device. That also > > complicates > > > migration. > > > > > > Regards, > > > Akihiko Odaki > > > > > > Hi Akihiko, > > > > > > As far as I understand, the feature to export dma-bufs from the > > > virtgpu was introduced as part of the virtio cross-device sharing > > > proposal [1]. Thus, it shall be posible. When virtgpu ASSING_UUID, > > > it exports and identifies the dmabuf resource, so that when the > > dmabuf gets > > > shared inside the guest (e.g., with virtio-video), we can use the > > assigned > > > UUID to find the dmabuf in the host (using the patch that I > > linked above), > > > and import it. > > > > > > [1] - https://lwn.net/Articles/828988/ > > <https://lwn.net/Articles/828988/> <https://lwn.net/Articles/828988/ > > <https://lwn.net/Articles/828988/>> > > > > The problem is that virtio-gpu can have other kind of resources like > > pixman and OpenGL textures and manage them and DMA-BUFs with unified > > resource ID. > > > > > > I see. > > > > > > So you cannot change: > > g_hash_table_insert(g->resource_uuids, > > GUINT_TO_POINTER(assign.resource_id), uuid); > > by: > > virtio_add_dmabuf(uuid, assign.resource_id); > > > > assign.resource_id is not DMA-BUF file descriptor, and the underlying > > resource my not be DMA-BUF at first place. > > > > > > I didn't really look into the patch in-depth, so the code was intended > > to give an idea of how the implementation would look like with > > the cross-device patch API. Indeed, it is not the resource_id, > > (I just took a brief look at the virtio specificacion 1.2), but the > > underlying > > resource what we want to use here. > > > > > > Also, since this lives in the common code that is not used only by > > virtio-gpu-gl but also virtio-gpu, which supports migration, we also > > need to take care of that. It is not a problem for DMA-BUF as > > DMA-BUF is > > not migratable anyway, but the situation is different in this case. > > > > Implementing cross-device sharing is certainly a possibility, but > that > > requires more than dealing with DMA-BUFs. > > > > > > So, if I understood correctly, dmabufs are just a subset of the resources > > that the gpu manages, or can assign UUIDs to. I am not sure why > > the v
Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
On Wed, Sep 13, 2023 at 2:22 PM Akihiko Odaki wrote: > On 2023/09/13 20:34, Albert Esteve wrote: > > > > > > On Wed, Sep 13, 2023 at 12:34 PM Akihiko Odaki > <mailto:akihiko.od...@daynix.com>> wrote: > > > > On 2023/09/13 16:55, Albert Esteve wrote: > > > Hi Antonio, > > > > > > If I'm not mistaken, this patch is related with: > > > > > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > > > > > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > >> > > > IMHO, ideally, virtio-gpu and vhost-user-gpu both, would use the > > > infrastructure from the patch I linked to store the > > > virtio objects, so that they can be later shared with other > devices. > > > > I don't think such sharing is possible because the resources are > > identified by IDs that are local to the device. That also complicates > > migration. > > > > Regards, > > Akihiko Odaki > > > > Hi Akihiko, > > > > As far as I understand, the feature to export dma-bufs from the > > virtgpu was introduced as part of the virtio cross-device sharing > > proposal [1]. Thus, it shall be posible. When virtgpu ASSING_UUID, > > it exports and identifies the dmabuf resource, so that when the dmabuf > gets > > shared inside the guest (e.g., with virtio-video), we can use the > assigned > > UUID to find the dmabuf in the host (using the patch that I linked > above), > > and import it. > > > > [1] - https://lwn.net/Articles/828988/ <https://lwn.net/Articles/828988/ > > > > The problem is that virtio-gpu can have other kind of resources like > pixman and OpenGL textures and manage them and DMA-BUFs with unified > resource ID. > I see. > > So you cannot change: > g_hash_table_insert(g->resource_uuids, > GUINT_TO_POINTER(assign.resource_id), uuid); > by: > virtio_add_dmabuf(uuid, assign.resource_id); > > assign.resource_id is not DMA-BUF file descriptor, and the underlying > resource my not be DMA-BUF at first place. > I didn't really look into the patch in-depth, so the code was intended to give an idea of how the implementation would look like with the cross-device patch API. Indeed, it is not the resource_id, (I just took a brief look at the virtio specificacion 1.2), but the underlying resource what we want to use here. > > Also, since this lives in the common code that is not used only by > virtio-gpu-gl but also virtio-gpu, which supports migration, we also > need to take care of that. It is not a problem for DMA-BUF as DMA-BUF is > not migratable anyway, but the situation is different in this case. > > Implementing cross-device sharing is certainly a possibility, but that > requires more than dealing with DMA-BUFs. > > So, if I understood correctly, dmabufs are just a subset of the resources that the gpu manages, or can assign UUIDs to. I am not sure why the virt gpu driver would want to send a ASSIGN_UUID for anything that is not a dmabuf (are we sure it does?), but I am not super familiarized with virtgpu to begin with. But I see that internally, the GPU specs relate a UUID with a resource_id, so we still need both tables: - one to relate UUID with resource_id to be able to locate the underlying resource - the table that holds the dmabuf with the UUID for cross-device sharing With that in mind, sounds to me that the support for cross-device sharing could be added on top of this patch, once https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01850.html lands. I hope that makes sense. Regards, Albert
Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
On Wed, Sep 13, 2023 at 12:34 PM Akihiko Odaki wrote: > On 2023/09/13 16:55, Albert Esteve wrote: > > Hi Antonio, > > > > If I'm not mistaken, this patch is related with: > > https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html > > <https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html> > > IMHO, ideally, virtio-gpu and vhost-user-gpu both, would use the > > infrastructure from the patch I linked to store the > > virtio objects, so that they can be later shared with other devices. > > I don't think such sharing is possible because the resources are > identified by IDs that are local to the device. That also complicates > migration. > > Regards, > Akihiko Odaki > > Hi Akihiko, As far as I understand, the feature to export dma-bufs from the virtgpu was introduced as part of the virtio cross-device sharing proposal [1]. Thus, it shall be posible. When virtgpu ASSING_UUID, it exports and identifies the dmabuf resource, so that when the dmabuf gets shared inside the guest (e.g., with virtio-video), we can use the assigned UUID to find the dmabuf in the host (using the patch that I linked above), and import it. [1] - https://lwn.net/Articles/828988/
Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID
Hi Antonio, If I'm not mistaken, this patch is related with: https://lists.gnu.org/archive/html/qemu-devel/2023-09/msg01853.html IMHO, ideally, virtio-gpu and vhost-user-gpu both, would use the infrastructure from the patch I linked to store the virtio objects, so that they can be later shared with other devices. Which, in terms of code, would mean changing: g_hash_table_insert(g->resource_uuids, GUINT_TO_POINTER(assign.resource_id), uuid); by: virtio_add_dmabuf(uuid, assign.resource_id); ...and simplify part of the infrastructure. Let me know what you think. Regard, Albert
