Re: [QEMU PATCH v4 10/13] virtio-gpu: Resource UUID

[Huang Rui <ray.huang@xxxxxxx>]

On Thu, Aug 31, 2023 at 06:36:57PM +0800, Akihiko Odaki wrote:
> On 2023/08/31 18:32, Huang Rui wrote:
> > From: Antonio Caggiano <antonio.caggiano@xxxxxxxxxxxxx>
> > 
> > Enable resource UUID feature and implement command resource assign UUID.
> > This is done by introducing a hash table to map resource IDs to their
> > UUIDs.
> 
> The hash table does not seem to be stored during migration.

May I know whether you point g->resource_uuids table data in VirtIOGPU
device should be stored in virtio_gpu_save() and resumed in
virtio_gpu_load() for virtio migration?

> 
> > 
> > Signed-off-by: Antonio Caggiano <antonio.caggiano@xxxxxxxxxxxxx>
> > Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> > ---
> > 
> > v1->v2:
> >     - Separate declarations from code.
> > 
> >   hw/display/trace-events        |  1 +
> >   hw/display/virtio-gpu-base.c   |  2 ++
> >   hw/display/virtio-gpu-virgl.c  | 21 +++++++++++++++++
> >   hw/display/virtio-gpu.c        | 41 ++++++++++++++++++++++++++++++++++
> >   include/hw/virtio/virtio-gpu.h |  4 ++++
> >   5 files changed, 69 insertions(+)
> > 
> > diff --git a/hw/display/trace-events b/hw/display/trace-events
> > index 2336a0ca15..54d6894c59 100644
> > --- a/hw/display/trace-events
> > +++ b/hw/display/trace-events
> > @@ -41,6 +41,7 @@ virtio_gpu_cmd_res_create_blob(uint32_t res, uint64_t 
> > size) "res 0x%x, size %" P
> >   virtio_gpu_cmd_res_unref(uint32_t res) "res 0x%x"
> >   virtio_gpu_cmd_res_back_attach(uint32_t res) "res 0x%x"
> >   virtio_gpu_cmd_res_back_detach(uint32_t res) "res 0x%x"
> > +virtio_gpu_cmd_res_assign_uuid(uint32_t res) "res 0x%x"
> >   virtio_gpu_cmd_res_xfer_toh_2d(uint32_t res) "res 0x%x"
> >   virtio_gpu_cmd_res_xfer_toh_3d(uint32_t res) "res 0x%x"
> >   virtio_gpu_cmd_res_xfer_fromh_3d(uint32_t res) "res 0x%x"
> > diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c
> > index 4f2b0ba1f3..f44388715c 100644
> > --- a/hw/display/virtio-gpu-base.c
> > +++ b/hw/display/virtio-gpu-base.c
> > @@ -236,6 +236,8 @@ virtio_gpu_base_get_features(VirtIODevice *vdev, 
> > uint64_t features,
> >           features |= (1 << VIRTIO_GPU_F_CONTEXT_INIT);
> >       }
> >   
> > +    features |= (1 << VIRTIO_GPU_F_RESOURCE_UUID);
> > +
> >       return features;
> >   }
> >   
> > diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
> > index 17b634d4ee..1a996a08fc 100644
> > --- a/hw/display/virtio-gpu-virgl.c
> > +++ b/hw/display/virtio-gpu-virgl.c
> > @@ -36,6 +36,7 @@ static void virgl_cmd_create_resource_2d(VirtIOGPU *g,
> >   {
> >       struct virtio_gpu_resource_create_2d c2d;
> >       struct virgl_renderer_resource_create_args args;
> > +    struct virtio_gpu_simple_resource *res;
> >   
> >       VIRTIO_GPU_FILL_CMD(c2d);
> >       trace_virtio_gpu_cmd_res_create_2d(c2d.resource_id, c2d.format,
> > @@ -53,6 +54,14 @@ static void virgl_cmd_create_resource_2d(VirtIOGPU *g,
> >       args.nr_samples = 0;
> >       args.flags = VIRTIO_GPU_RESOURCE_FLAG_Y_0_TOP;
> >       virgl_renderer_resource_create(&args, NULL, 0);
> > +
> > +    res = g_new0(struct virtio_gpu_simple_resource, 1);
> > +    if (!res) {
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_OUT_OF_MEMORY;
> > +        return;
> 
> virglrenderer thinks the resource is alive in such a situation.

Yes, so we can move the resource allocation in front of below virglrenderer
resource creation.

virgl_renderer_resource_create(&args, NULL, 0);

> 
> > +    }
> > +    res->resource_id = c2d.resource_id;
> > +    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
> >   }
> >   
> >   static void virgl_cmd_create_resource_3d(VirtIOGPU *g,
> > @@ -60,6 +69,7 @@ static void virgl_cmd_create_resource_3d(VirtIOGPU *g,
> >   {
> >       struct virtio_gpu_resource_create_3d c3d;
> >       struct virgl_renderer_resource_create_args args;
> > +    struct virtio_gpu_simple_resource *res;
> >   
> >       VIRTIO_GPU_FILL_CMD(c3d);
> >       trace_virtio_gpu_cmd_res_create_3d(c3d.resource_id, c3d.format,
> > @@ -77,6 +87,14 @@ static void virgl_cmd_create_resource_3d(VirtIOGPU *g,
> >       args.nr_samples = c3d.nr_samples;
> >       args.flags = c3d.flags;
> >       virgl_renderer_resource_create(&args, NULL, 0);
> > +
> > +    res = g_new0(struct virtio_gpu_simple_resource, 1);
> > +    if (!res) {
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_OUT_OF_MEMORY;
> > +        return;
> > +    }
> > +    res->resource_id = c3d.resource_id;
> > +    QTAILQ_INSERT_HEAD(&g->reslist, res, next);
> >   }
> >   
> >   static void virgl_resource_destroy(VirtIOGPU *g,
> > @@ -682,6 +700,9 @@ void virtio_gpu_virgl_process_cmd(VirtIOGPU *g,
> >           /* TODO add security */
> >           virgl_cmd_ctx_detach_resource(g, cmd);
> >           break;
> > +    case VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID:
> > +        virtio_gpu_resource_assign_uuid(g, cmd);
> > +        break;
> >       case VIRTIO_GPU_CMD_GET_CAPSET_INFO:
> >           virgl_cmd_get_capset_info(g, cmd);
> >           break;
> > diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
> > index cc4c1f81bb..770e4747e3 100644
> > --- a/hw/display/virtio-gpu.c
> > +++ b/hw/display/virtio-gpu.c
> > @@ -966,6 +966,37 @@ virtio_gpu_resource_detach_backing(VirtIOGPU *g,
> >       virtio_gpu_cleanup_mapping(g, res);
> >   }
> >   
> > +void virtio_gpu_resource_assign_uuid(VirtIOGPU *g,
> > +                                     struct virtio_gpu_ctrl_command *cmd)
> > +{
> > +    struct virtio_gpu_simple_resource *res;
> > +    struct virtio_gpu_resource_assign_uuid assign;
> > +    struct virtio_gpu_resp_resource_uuid resp;
> > +    QemuUUID *uuid = NULL;
> 
> This initialization is unnecessary.

Yes, will remove it.

> 
> > +
> > +    VIRTIO_GPU_FILL_CMD(assign);
> > +    virtio_gpu_bswap_32(&assign, sizeof(assign));
> > +    trace_virtio_gpu_cmd_res_assign_uuid(assign.resource_id);
> > +
> > +    res = virtio_gpu_find_check_resource(g, assign.resource_id, false, 
> > __func__, &cmd->error);
> > +    if (!res) {
> > +        return;
> > +    }
> > +
> > +    memset(&resp, 0, sizeof(resp));
> > +    resp.hdr.type = VIRTIO_GPU_RESP_OK_RESOURCE_UUID;
> > +
> > +    uuid = g_hash_table_lookup(g->resource_uuids, 
> > GUINT_TO_POINTER(assign.resource_id));
> > +    if (!uuid) {
> > +        uuid = g_new(QemuUUID, 1);
> > +        qemu_uuid_generate(uuid);
> > +        g_hash_table_insert(g->resource_uuids, 
> > GUINT_TO_POINTER(assign.resource_id), uuid);
> > +    }
> > +
> > +    memcpy(resp.uuid, uuid, sizeof(QemuUUID));
> > +    virtio_gpu_ctrl_response(g, cmd, &resp.hdr, sizeof(resp));
> > +}
> > +
> >   void virtio_gpu_simple_process_cmd(VirtIOGPU *g,
> >                                      struct virtio_gpu_ctrl_command *cmd)
> >   {
> > @@ -1014,6 +1045,9 @@ void virtio_gpu_simple_process_cmd(VirtIOGPU *g,
> >       case VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING:
> >           virtio_gpu_resource_detach_backing(g, cmd);
> >           break;
> > +    case VIRTIO_GPU_CMD_RESOURCE_ASSIGN_UUID:
> > +        virtio_gpu_resource_assign_uuid(g, cmd);
> > +        break;
> >       default:
> >           cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
> >           break;
> > @@ -1393,12 +1427,15 @@ void virtio_gpu_device_realize(DeviceState *qdev, 
> > Error **errp)
> >       QTAILQ_INIT(&g->reslist);
> >       QTAILQ_INIT(&g->cmdq);
> >       QTAILQ_INIT(&g->fenceq);
> > +
> > +    g->resource_uuids = g_hash_table_new_full(NULL, NULL, NULL, g_free);
> >   }
> >   
> >   static void virtio_gpu_device_unrealize(DeviceState *qdev)
> >   {
> >       VirtIOGPU *g = VIRTIO_GPU(qdev);
> >   
> > +    g_hash_table_destroy(g->resource_uuids);
> >       g_clear_pointer(&g->ctrl_bh, qemu_bh_delete);
> >       g_clear_pointer(&g->cursor_bh, qemu_bh_delete);
> >       g_clear_pointer(&g->reset_bh, qemu_bh_delete);
> > @@ -1452,6 +1489,10 @@ void virtio_gpu_reset(VirtIODevice *vdev)
> >           g_free(cmd);
> >       }
> >   
> > +    if (g->resource_uuids) {
> 
> Isn't g->resource_uuids always non-NULL?

Yes, right. The if check should be superfluous. Will remove it.

Thanks,
Ray

> 
> > +        g_hash_table_remove_all(g->resource_uuids);
> > +    }
> > +
> >       virtio_gpu_base_reset(VIRTIO_GPU_BASE(vdev));
> >   }
> >   
> > diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
> > index b9adc28071..aa94b1b697 100644
> > --- a/include/hw/virtio/virtio-gpu.h
> > +++ b/include/hw/virtio/virtio-gpu.h
> > @@ -208,6 +208,8 @@ struct VirtIOGPU {
> >           QTAILQ_HEAD(, VGPUDMABuf) bufs;
> >           VGPUDMABuf *primary[VIRTIO_GPU_MAX_SCANOUTS];
> >       } dmabuf;
> > +
> > +    GHashTable *resource_uuids;
> >   };
> >   
> >   struct VirtIOGPUClass {
> > @@ -285,6 +287,8 @@ void virtio_gpu_cleanup_mapping_iov(VirtIOGPU *g,
> >                                       struct iovec *iov, uint32_t count);
> >   void virtio_gpu_cleanup_mapping(VirtIOGPU *g,
> >                                   struct virtio_gpu_simple_resource *res);
> > +void virtio_gpu_resource_assign_uuid(VirtIOGPU *g,
> > +                                     struct virtio_gpu_ctrl_command *cmd);
> >   void virtio_gpu_process_cmdq(VirtIOGPU *g);
> >   void virtio_gpu_device_realize(DeviceState *qdev, Error **errp);
> >   void virtio_gpu_reset(VirtIODevice *vdev);