Re: [PATCH v14 10/14] virtio-gpu: Support blob scanout using dmabuf fd

[Akihiko Odaki <akihiko.odaki@daynix.com>]

On 2024/06/16 10:03, Dmitry Osipenko wrote:
> From: Robert Beckett <bob.beckett@collabora.com>
> 
> Support displaying blob resources by handling SET_SCANOUT_BLOB
> command.
> 
> Signed-by: Antonio Caggiano <antonio.caggiano@collabora.com>
> Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
> Signed-off-by: Huang Rui <ray.huang@amd.com>
> Reviewed-by: Antonio Caggiano <quic_acaggian@quicinc.com>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
>   hw/display/virtio-gpu-virgl.c  | 109 +++++++++++++++++++++++++++++++++
>   hw/display/virtio-gpu.c        |  12 ++--
>   include/hw/virtio/virtio-gpu.h |   7 +++
>   3 files changed, 122 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
> index 3ffea478e723..60befab7efc2 100644
> --- a/hw/display/virtio-gpu-virgl.c
> +++ b/hw/display/virtio-gpu-virgl.c
> @@ -17,6 +17,8 @@
>   #include "trace.h"
>   #include "hw/virtio/virtio.h"
>   #include "hw/virtio/virtio-gpu.h"
> +#include "hw/virtio/virtio-gpu-bswap.h"
> +#include "hw/virtio/virtio-gpu-pixman.h"
>   
>   #include "ui/egl-helpers.h"
>   
> @@ -78,6 +80,7 @@ static void virgl_cmd_create_resource_2d(VirtIOGPU *g,
>       res->base.height = c2d.height;
>       res->base.format = c2d.format;
>       res->base.resource_id = c2d.resource_id;
> +    res->base.dmabuf_fd = -1;
>       QTAILQ_INSERT_HEAD(&g->reslist, &res->base, next);
>   
>       args.handle = c2d.resource_id;
> @@ -125,6 +128,7 @@ static void virgl_cmd_create_resource_3d(VirtIOGPU *g,
>       res->base.height = c3d.height;
>       res->base.format = c3d.format;
>       res->base.resource_id = c3d.resource_id;
> +    res->base.dmabuf_fd = -1;
>       QTAILQ_INSERT_HEAD(&g->reslist, &res->base, next);
>   
>       args.handle = c3d.resource_id;
> @@ -509,6 +513,106 @@ static void virgl_cmd_get_capset(VirtIOGPU *g,
>       g_free(resp);
>   }
>   
> +#if VIRGL_VERSION_MAJOR >= 1
> +static void virgl_cmd_set_scanout_blob(VirtIOGPU *g,
> +                                       struct virtio_gpu_ctrl_command *cmd)
> +{
> +    struct virtio_gpu_framebuffer fb = { 0 };
> +    struct virgl_renderer_resource_info info;
> +    struct virtio_gpu_virgl_resource *res;
> +    struct virtio_gpu_set_scanout_blob ss;
> +    uint64_t fbend;
> +
> +    VIRTIO_GPU_FILL_CMD(ss);
> +    virtio_gpu_scanout_blob_bswap(&ss);
> +    trace_virtio_gpu_cmd_set_scanout_blob(ss.scanout_id, ss.resource_id,
> +                                          ss.r.width, ss.r.height, ss.r.x,
> +                                          ss.r.y);
> +
> +    if (ss.scanout_id >= g->parent_obj.conf.max_outputs) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout id specified %d",
> +                      __func__, ss.scanout_id);
> +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_SCANOUT_ID;
> +        return;
> +    }
> +
> +    if (ss.resource_id == 0) {
> +        virtio_gpu_disable_scanout(g, ss.scanout_id);
> +        return;
> +    }
> +
> +    if (ss.width < 16 ||
> +        ss.height < 16 ||
> +        ss.r.x + ss.r.width > ss.width ||
> +        ss.r.y + ss.r.height > ss.height) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: illegal scanout %d bounds for"
> +                      " resource %d, rect (%d,%d)+%d,%d, fb %d %d\n",
> +                      __func__, ss.scanout_id, ss.resource_id,
> +                      ss.r.x, ss.r.y, ss.r.width, ss.r.height,
> +                      ss.width, ss.height);
> +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
> +        return;
> +    }
> +
> +    res = virtio_gpu_virgl_find_resource(g, ss.resource_id);
> +    if (!res) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource does not exist %d\n",
> +                      __func__, ss.resource_id);
> +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> +        return;
> +    }
> +    if (virgl_renderer_resource_get_info(ss.resource_id, &info)) {
> +        qemu_log_mask(LOG_GUEST_ERROR, "%s: resource does not have info %d\n",
> +                      __func__, ss.resource_id);
> +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> +        return;
> +    }
> +    if (res->base.dmabuf_fd < 0) {
> +        res->base.dmabuf_fd = info.fd;

res->base.dmabuf_fd is conditionally assigned but 
virgl_renderer_resource_get_info() is called unconditionally, which is 
inconsistent.

The relevant code is better to be moved into 
virgl_cmd_resource_create_blob() for consistenty with 
virtio_gpu_resource_create_blob().