Re: [PATCH v1 2/3] virtio-gpu.c: add resource_destroy class method

[Manos Pitsidianakis]

On Fri, 26 Jan 2024 at 17:22, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> Hi Manos,
>
> On 26/1/24 15:41, Manos Pitsidianakis wrote:
> > When destroying/unrefing resources, devices such as virtio-gpu-rutabaga
> > need to do their own bookkeeping (free rutabaga resources that are
> > associated with the virtio_gpu_simple_resource).
> >
> > This commit adds a class method so that virtio-gpu-rutabaga can override
> > it in the next commit.
> >
> > Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> > ---
> >   hw/display/virtio-gpu.c        | 19 ++++++++++++++++---
> >   include/hw/virtio/virtio-gpu.h |  2 ++
> >   2 files changed, 18 insertions(+), 3 deletions(-)
>
>
> >   static void virtio_gpu_resource_unref(VirtIOGPU *g,
> > @@ -1488,11 +1491,20 @@ static void virtio_gpu_device_unrealize(DeviceState 
> > *qdev)
> >   static void virtio_gpu_reset_bh(void *opaque)
> >   {
> >       VirtIOGPU *g = VIRTIO_GPU(opaque);
> > +    VirtIOGPUClass *vgc = VIRTIO_GPU_GET_CLASS(g);
> >       struct virtio_gpu_simple_resource *res, *tmp;
> > +    int32_t result, resource_id;
> >       int i = 0;
> >
> >       QTAILQ_FOREACH_SAFE(res, &g->reslist, next, tmp) {
> > -        virtio_gpu_resource_destroy(g, res);
> > +        resource_id = res->resource_id;
> > +        result = vgc->resource_destroy(g, res);
> > +        if (result) {
> > +            error_report("%s: %s resource_destroy"
> > +                         "for resource_id = %d failed with return value = 
> > %d;",
>
> '%d' is for 'int', for 'int32_t' you need 'PRId32'.

Thanks,

> But why return that type instead of 'int'?

Because devices might use FFI, and other languages use fixed size
integers. Since rutabaga is the only one doing this right now, I used
their integer width.

> > +                         __func__, object_get_typename(OBJECT(g)), 
> > resource_id,
> > +                         result);
> > +        }
> >       }
>
>
> > diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h
> > index 584ba2ed73..5683354236 100644
> > --- a/include/hw/virtio/virtio-gpu.h
> > +++ b/include/hw/virtio/virtio-gpu.h
> > @@ -219,6 +219,8 @@ struct VirtIOGPUClass {
> >       void (*update_cursor_data)(VirtIOGPU *g,
> >                                  struct virtio_gpu_scanout *s,
> >                                  uint32_t resource_id);
> > +    int32_t (*resource_destroy)(VirtIOGPU *g,
> > +                                struct virtio_gpu_simple_resource *res);
> >   };
> >
> >   struct VirtIOGPUGL {
>