Re: [PATCH v2 3/3] virtio-gpu-rutabaga.c: override resource_destroy method

[Manos Pitsidianakis]

On Tue, 30 Jan 2024 at 15:10, Marc-André Lureau
<marcandre.lureau@gmail.com> wrote:
>
> Hi
>
> On Tue, Jan 30, 2024 at 5:01 PM Manos Pitsidianakis
> <manos.pitsidianakis@linaro.org> wrote:
> >
> > On Tue, 30 Jan 2024 at 14:50, Marc-André Lureau
> > <marcandre.lureau@gmail.com> wrote:
> > >
> > > Hi
> > >
> > > On Mon, Jan 29, 2024 at 7:46 PM Manos Pitsidianakis
> > > <manos.pitsidianakis@linaro.org> wrote:
> > > >
> > > > When the Rutabaga GPU device frees resources, it calls
> > > > rutabaga_resource_unref for that resource_id. However, when the generic
> > > > VirtIOGPU functions destroys resources, it only removes the
> > > > virtio_gpu_simple_resource from the device's VirtIOGPU->reslist list.
> > > > The rutabaga resource associated with that resource_id is then leaked.
> > > >
> > > > This commit overrides the resource_destroy class method introduced in
> > > > the previous commit to fix this.
> > > >
> > > > Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> > > > ---
> > > >  hw/display/virtio-gpu-rutabaga.c | 51 ++++++++++++++++++++++++--------
> > > >  1 file changed, 39 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/hw/display/virtio-gpu-rutabaga.c 
> > > > b/hw/display/virtio-gpu-rutabaga.c
> > > > index 9e67f9bd51..6ac0776005 100644
> > > > --- a/hw/display/virtio-gpu-rutabaga.c
> > > > +++ b/hw/display/virtio-gpu-rutabaga.c
> > > > @@ -148,14 +148,42 @@ rutabaga_cmd_create_resource_3d(VirtIOGPU *g,
> > > >  }
> > > >
> > > >  static void
> > > > +virtio_gpu_rutabaga_resource_unref(VirtIOGPU *g,
> > > > +                                   struct virtio_gpu_simple_resource 
> > > > *res,
> > > > +                                   Error **errp)
> > > > +{
> > > > +    int32_t result;
> > > > +    const char *strerror = NULL;
> > > > +    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
> > > > +
> > > > +    result = rutabaga_resource_unref(vr->rutabaga, res->resource_id);
> > > > +    if (result) {
> > > > +        error_setg(errp, "%s: rutabaga_resource_unref returned %"PRIi32
> > > > +                   " for resource_id = %"PRIu32, __func__, result,
> > > > +                   res->resource_id);
> > > > +        strerror = strerrorname_np((int)result);
> > > > +        if (strerror != NULL) {
> > > > +            error_append_hint(errp, "%s: %s\n",
> > > > +                              strerror, strerrordesc_np((int)result) ? 
> > > > : "");
> > > > +        }
> > > > +    }
> > >
> > > There is error_setg_errno()
> >
> > I did not use it on purpose because I was not certain if rutabaga_gfx
> > starts using other error numbers in the future. I don't like my
> > approach but I don't like assuming it's an errno either to be
> > honest... Which one seems better to you?
> >
>
> In that case, don't use strerrordesc_np() either :)

strerrordesc_np will be valid if strerrorname_np() does not return NULL.

> I think we can assume they will keep using errno though, unless they
> clearly communicate this and break API, which seems unlikely to me.

I will use error_setg_errno then, thanks!

Manos

> > Thanks,
> > Manos
> >
> > > > +
> > > > +    if (res->image) {
> > > > +        pixman_image_unref(res->image);
> > > > +    }
> > > > +
> > > > +    QTAILQ_REMOVE(&g->reslist, res, next);
> > > > +    g_free(res);
> > > > +}
> > > > +
> > > > +static void
> > > >  rutabaga_cmd_resource_unref(VirtIOGPU *g,
> > > >                              struct virtio_gpu_ctrl_command *cmd)
> > > >  {
> > > > -    int32_t result;
> > > > +    int32_t result = 0;
> > > >      struct virtio_gpu_simple_resource *res;
> > > >      struct virtio_gpu_resource_unref unref;
> > > > -
> > > > -    VirtIOGPURutabaga *vr = VIRTIO_GPU_RUTABAGA(g);
> > > > +    Error *local_err = NULL;
> > > >
> > > >      VIRTIO_GPU_FILL_CMD(unref);
> > > >
> > > > @@ -164,15 +192,14 @@ rutabaga_cmd_resource_unref(VirtIOGPU *g,
> > > >      res = virtio_gpu_find_resource(g, unref.resource_id);
> > > >      CHECK(res, cmd);
> > > >
> > > > -    result = rutabaga_resource_unref(vr->rutabaga, unref.resource_id);
> > > > -    CHECK(!result, cmd);
> > > > -
> > > > -    if (res->image) {
> > > > -        pixman_image_unref(res->image);
> > > > +    virtio_gpu_rutabaga_resource_unref(g, res, &local_err);
> > > > +    if (local_err) {
> > > > +        error_report_err(local_err);
> > > > +        /* local_err was freed, do not reuse it. */
> > > > +        local_err = NULL;
> > > > +        result = 1;
> > > >      }
> > > > -
> > > > -    QTAILQ_REMOVE(&g->reslist, res, next);
> > > > -    g_free(res);
> > > > +    CHECK(!result, cmd);
> > > >  }
> > > >
> > > >  static void
> > > > @@ -1099,7 +1126,7 @@ static void 
> > > > virtio_gpu_rutabaga_class_init(ObjectClass *klass, void *data)
> > > >      vgc->handle_ctrl = virtio_gpu_rutabaga_handle_ctrl;
> > > >      vgc->process_cmd = virtio_gpu_rutabaga_process_cmd;
> > > >      vgc->update_cursor_data = virtio_gpu_rutabaga_update_cursor;
> > > > -
> > > > +    vgc->resource_destroy = virtio_gpu_rutabaga_resource_unref;
> > > >      vdc->realize = virtio_gpu_rutabaga_realize;
> > > >      device_class_set_props(dc, virtio_gpu_rutabaga_properties);
> > > >  }
> > > > --
> > > > γαῖα πυρί μιχθήτω
> > > >
> > >
> > >
> > > --
> > > Marc-André Lureau
>
>
>
> --
> Marc-André Lureau