virtio-gpu: Get FD for texture

virtio-gpu: Get FD for texture

[Antonio Caggiano]

Hi,

I am trying to support a Vulkan application in the guest 
(GTKGlArea+VirGL+venus) which needs to import a GL texture from a GL 
context.

Before doing that, I need to get a FD for that texture, therefore I 
tried with calling egl-helpers.h:egl_get_fd_for_texture() but I get an 
epoxy error:

 > No provider of eglCreateImageKHR found.  Requires one of:

 >   EGL_KHR_image

 >   EGL_KHR_image_base

This is a bit weird to me as I am sure I am running QEMU with iris and 
according to eglinfo both of these extensions are available.

Do you think my approach makes sense or I am doing something wrong 
somewhere?


Kind regards,
Antonio Caggiano

Re: virtio-gpu: Get FD for texture

[Antonio Caggiano]

I am starting to believe that the error is due to the fact that no 
EGLContext is active on the current thread (the one running the Vulkan 
application).

Trying to call eglMakeCurrent within this thread gives me an 
EGL_BAD_ACCESS error as the EGLContext associated to the GL texture 
belongs to a different thread.

Does that make sense?

Kind regards,
Antonio Caggiano

On 27/09/21 12:21, Antonio Caggiano wrote:
> Hi,
> 
> I am trying to support a Vulkan application in the guest 
> (GTKGlArea+VirGL+venus) which needs to import a GL texture from a GL 
> context.
> 
> Before doing that, I need to get a FD for that texture, therefore I 
> tried with calling egl-helpers.h:egl_get_fd_for_texture() but I get an 
> epoxy error:
> 
>  > No provider of eglCreateImageKHR found.  Requires one of:
> 
>  >   EGL_KHR_image
> 
>  >   EGL_KHR_image_base
> 
> This is a bit weird to me as I am sure I am running QEMU with iris and 
> according to eglinfo both of these extensions are available.
> 
> Do you think my approach makes sense or I am doing something wrong 
> somewhere?
> 
> 
> Kind regards,
> Antonio Caggiano

RE: virtio-gpu: Get FD for texture

[Kasireddy, Vivek]

Hi Antonio,

> 
> I am starting to believe that the error is due to the fact that no EGLContext is active on the
> current thread (the one running the Vulkan application).
[Kasireddy, Vivek] Which UI module (and Host environment) are you testing with?
gtk? egl-headless? Could you please provide more details about the environment and
the use-case?

> 
> Trying to call eglMakeCurrent within this thread gives me an EGL_BAD_ACCESS error
> as the EGLContext associated to the GL texture belongs to a different thread.
[Kasireddy, Vivek] IIUC, contexts can only be bound to one thread at a time. So you either
need to release the context in the other thread (eglMakeCurrent(NULL, NULL) before making
it current in your current thread or create a shared context between both the threads to be able
to share textures.

Thanks,
Vivek

> 
> Does that make sense?
> 
> Kind regards,
> Antonio Caggiano
> 
> On 27/09/21 12:21, Antonio Caggiano wrote:
> > Hi,
> >
> > I am trying to support a Vulkan application in the guest
> > (GTKGlArea+VirGL+venus) which needs to import a GL texture from a GL
> > context.
> >
> > Before doing that, I need to get a FD for that texture, therefore I
> > tried with calling egl-helpers.h:egl_get_fd_for_texture() but I get an
> > epoxy error:
> >
> >  > No provider of eglCreateImageKHR found.  Requires one of:
> >
> >  >   EGL_KHR_image
> >
> >  >   EGL_KHR_image_base
> >
> > This is a bit weird to me as I am sure I am running QEMU with iris and
> > according to eglinfo both of these extensions are available.
> >
> > Do you think my approach makes sense or I am doing something wrong
> > somewhere?
> >
> >
> > Kind regards,
> > Antonio Caggiano