Re: [QEMU PATCH v5 06/13] virtio-gpu: Support context init feature with virglrenderer

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

On 2023/09/17 14:45, Huang Rui wrote:
> On Sat, Sep 16, 2023 at 06:42:04PM +0800, Akihiko Odaki wrote:
>> On 2023/09/16 19:32, Huang Rui wrote:
>>> On Fri, Sep 15, 2023 at 11:20:46PM +0800, Akihiko Odaki wrote:
>>>> On 2023/09/15 20:11, Huang Rui wrote:
>>>>> Patch "virtio-gpu: CONTEXT_INIT feature" has added the context_init
>>>>> feature flags.
>>>>> We would like to enable the feature with virglrenderer, so add to create
>>>>> virgl renderer context with flags using context_id when valid.
>>>>>
>>>>> Originally-by: Antonio Caggiano <antonio.caggiano@collabora.com>
>>>>> Signed-off-by: Huang Rui <ray.huang@amd.com>
>>>>> ---
>>>>>
>>>>> V4 -> V5:
>>>>>        - Inverted patch 5 and 6 because we should configure
>>>>>          HAVE_VIRGL_CONTEXT_INIT firstly. (Philippe)
>>>>>
>>>>>     hw/display/virtio-gpu-virgl.c | 13 +++++++++++--
>>>>>     hw/display/virtio-gpu.c       |  2 ++
>>>>>     2 files changed, 13 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
>>>>> index 8bb7a2c21f..312953ec16 100644
>>>>> --- a/hw/display/virtio-gpu-virgl.c
>>>>> +++ b/hw/display/virtio-gpu-virgl.c
>>>>> @@ -106,8 +106,17 @@ static void virgl_cmd_context_create(VirtIOGPU *g,
>>>>>         trace_virtio_gpu_cmd_ctx_create(cc.hdr.ctx_id,
>>>>>                                         cc.debug_name);
>>>>>     
>>>>> -    virgl_renderer_context_create(cc.hdr.ctx_id, cc.nlen,
>>>>> -                                  cc.debug_name);
>>>>> +    if (cc.context_init) {
>>>>> +#ifdef HAVE_VIRGL_CONTEXT_INIT
>>>>> +        virgl_renderer_context_create_with_flags(cc.hdr.ctx_id,
>>>>> +                                                 cc.context_init,
>>>>> +                                                 cc.nlen,
>>>>> +                                                 cc.debug_name);
>>>>> +        return;
>>>>> +#endif
>>>>
>>>> This should deal with the case when context_init is set while
>>>> HAVE_VIRGL_CONTEXT_INIT is not defined.
>>>
>>> Actually, I received the comment below before:
>>>
>>> https://lore.kernel.org/qemu-devel/32588d0e-a1f2-30c4-5e9f-e6e7c4190b65@linaro.org/
>>>
>>> At original patch set, I have the case while HAVE_VIRGL_CONTEXT_INIT is set
>>> but HAVE_VIRGL_CONTEXT_INIT is not defined. But I think we may encounter
>>> the case that virgl_renderer_context_create_with_flags is not defined in
>>> virglrenderer early version. Should I bring the error message back?
>>>
>>> Thanks,
>>> Ray
>>
>> I suggest checking VIRTIO_GPU_FLAG_CONTEXT_INIT_ENABLED instead of
>> reporting an error here. Perhaps it may be easier to add #ifdef around:
>>   > +    DEFINE_PROP_BIT("context_init", VirtIOGPU, parent_obj.conf.flags,
>>   > +                    VIRTIO_GPU_FLAG_CONTEXT_INIT_ENABLED, false),
> 
> How about below changes: >
> ---
> diff --git a/hw/display/virtio-gpu-virgl.c b/hw/display/virtio-gpu-virgl.c
> index 8bb7a2c21f..54a3cfe136 100644
> --- a/hw/display/virtio-gpu-virgl.c
> +++ b/hw/display/virtio-gpu-virgl.c
> @@ -106,8 +106,15 @@ static void virgl_cmd_context_create(VirtIOGPU *g,
>       trace_virtio_gpu_cmd_ctx_create(cc.hdr.ctx_id,
>                                       cc.debug_name);
> 
> -    virgl_renderer_context_create(cc.hdr.ctx_id, cc.nlen,
> -                                  cc.debug_name);
> +    if (cc.context_init && virtio_gpu_context_init_enabled(g->conf)) {
> +        virgl_renderer_context_create_with_flags(cc.hdr.ctx_id,
> +                                                 cc.context_init,
> +                                                 cc.nlen,
> +                                                 cc.debug_name);
> +        return;
> +    }
> +
> +    virgl_renderer_context_create(cc.hdr.ctx_id, cc.nlen, cc.debug_name);
>   }
> 
>   static void virgl_cmd_context_destroy(VirtIOGPU *g,
> diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
> index be16efbd38..6ff2c8e92d 100644
> --- a/hw/display/virtio-gpu.c
> +++ b/hw/display/virtio-gpu.c
> @@ -1508,6 +1508,10 @@ static Property virtio_gpu_properties[] = {
>       DEFINE_PROP_BIT("blob", VirtIOGPU, parent_obj.conf.flags,
>                       VIRTIO_GPU_FLAG_BLOB_ENABLED, false),
>       DEFINE_PROP_SIZE("hostmem", VirtIOGPU, parent_obj.conf.hostmem, 0),
> +#ifdef HAVE_VIRGL_CONTEXT_INIT
> +    DEFINE_PROP_BIT("context_init", VirtIOGPU, parent_obj.conf.flags,
> +                    VIRTIO_GPU_FLAG_CONTEXT_INIT_ENABLED, true),
> +#endif
>       DEFINE_PROP_END_OF_LIST(),
>   };
> 

It looks better, but not having #ifdef around 
virgl_renderer_context_create_with_flags() will result in a link error 
with old virglrenderer.