Re: [PATCH v6 11/11] virtio-gpu: make blob scanout use dmabuf fd

[Pierre-Eric Pelloux-Prayer <pierre-eric@xxxxxxxxx>]

Le 21/12/2023 à 07:25, Akihiko Odaki a écrit :
> On 2023/12/19 16:53, Huang Rui wrote:
> > From: Robert Beckett <bob.beckett@xxxxxxxxxxxxx>
> >
> > This relies on a virglrenderer change to include the dmabuf fd when
> > returning resource info.
> >
> > Signed-off-by: Robert Beckett <bob.beckett@xxxxxxxxxxxxx>
> > Signed-off-by: Huang Rui <ray.huang@xxxxxxx>
> > ---
> >
> > Changes in v6:
> > - Add scanout_blob function for virtio-gpu-virgl.
> > - Update for new virgl_gpu_resource.
> >
> >   hw/display/virtio-gpu-virgl.c  | 104 +++++++++++++++++++++++++++++++++
> >   hw/display/virtio-gpu.c        |   4 +-
> >   include/hw/virtio/virtio-gpu.h |   6 ++
> >   3 files changed, 112 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
> > index c523a6717a..c384225a98 100644
> > --- a/hw/display/virtio-gpu-virgl.c
> > +++ b/hw/display/virtio-gpu-virgl.c
> > @@ -18,6 +18,7 @@
> >   #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"
> > @@ -726,6 +727,106 @@ static void virgl_cmd_resource_unmap_blob(VirtIOGPU *g,
> >       object_unparent(OBJECT(mr));
> >   }
> > +static void virgl_cmd_set_scanout_blob(VirtIOGPU *g,
> > +                                       struct virtio_gpu_ctrl_command *cmd)
> > +{
> > +    struct virgl_gpu_resource *vres;
> > +    struct virtio_gpu_framebuffer fb = { 0 };
> > +    struct virtio_gpu_set_scanout_blob ss;
> > +    struct virgl_renderer_resource_info info;
> > +    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;
> > +    }
> > +
> > +    if (!console_has_gl(g->parent_obj.scanout[ss.scanout_id].con)) {
> Shouldn't OpenGL always be available for virgl?
>
> > +        qemu_log_mask(LOG_GUEST_ERROR, "%s: unable to scanout blot without 
> > GL!\n", __func__);
> > +        return;
> > +    }
> > +
> > +    vres = virgl_gpu_find_resource(g, ss.resource_id);
> > +    if (!vres) {
> > +        qemu_log_mask(LOG_GUEST_ERROR,
> > +                      "%s: illegal resource specified %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: illegal virgl resource specified %d\n",
> > +                      __func__, ss.resource_id);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_RESOURCE_ID;
> > +        return;
> > +    }
> > +    if (!vres->res.dmabuf_fd && info.fd)
> > +        vres->res.dmabuf_fd = info.fd;
> > +
> > +    fb.format = virtio_gpu_get_pixman_format(ss.format);
> > +    if (!fb.format) {
> > +        qemu_log_mask(LOG_GUEST_ERROR,
> > +                      "%s: host couldn't handle guest format %d\n",
> > +                      __func__, ss.format);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
> > +        return;
> > +    }
> > +
> > +    fb.bytes_pp = DIV_ROUND_UP(PIXMAN_FORMAT_BPP(fb.format), 8);
> > +    fb.width = ss.width;
> > +    fb.height = ss.height;
> > +    fb.stride = ss.strides[0];
> > +    fb.offset = ss.offsets[0] + ss.r.x * fb.bytes_pp + ss.r.y * fb.stride;
> > +
> > +    fbend = fb.offset;
> > +    fbend += fb.stride * (ss.r.height - 1);
> > +    fbend += fb.bytes_pp * ss.r.width;
> > +    if (fbend > vres->res.blob_size) {
> > +        qemu_log_mask(LOG_GUEST_ERROR,
> > +                      "%s: fb end out of range\n",
> > +                      __func__);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
> > +        return;
> > +    }
> > +
> > +    g->parent_obj.enable = 1;
> > +    if (virtio_gpu_update_dmabuf(g, ss.scanout_id, &vres->res,
> > +                                 &fb, &ss.r)) {
> > +        qemu_log_mask(LOG_GUEST_ERROR,
> > +                      "%s: failed to update dmabuf\n", __func__);
> > +        cmd->error = VIRTIO_GPU_RESP_ERR_INVALID_PARAMETER;
> > +        return;
> > +    }
> > +    virtio_gpu_update_scanout(g, ss.scanout_id, &vres->res, &ss.r);
> > +}
> > +
> >   #endif /* HAVE_VIRGL_RESOURCE_BLOB */
> >   void virtio_gpu_virgl_process_cmd(VirtIOGPU *g,
> > @@ -807,6 +908,9 @@ void virtio_gpu_virgl_process_cmd(VirtIOGPU *g,
> >       case VIRTIO_GPU_CMD_RESOURCE_UNMAP_BLOB:
> >           virgl_cmd_resource_unmap_blob(g, cmd);
> >           break;
> > +    case VIRTIO_GPU_CMD_SET_SCANOUT_BLOB:
> VIRTIO_GPU_CMD_SET_SCANOUT_BLOB support should be added before allowing the 
> user to enable the resource blob support.
It seems that two patches were squashed together:

- "virtio-gpu: Handle set scanout blob command" by Antonio Caggiano
- "virtio-gpu: Handle set scanout blob command" by Bob Beckett

Restoring the original patches with the appropriate S-o-b tags seems the right 
thing to do.

Thanks,
Pierre-Eric
> You should also check if virtio_vdev_has_feature(VIRTIO_DEVICE(g), 
> VIRTIO_GPU_F_RESOURCE_BLOB). It also applies to other resource blob commands 
> though I failed to note that for the earlier patch.