glxinfo之Video Memory大小

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mesa中的显存大小：

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$glxinfo -B
name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD OLAND (DRM 2.50.0, 5.3.8-050308-generic, LLVM 8.0.0) (0x6611)
    Version: 19.1.6
    Accelerated: yes
    Video memory: 1024MB <----------- 显存
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 4.5
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.2

glxinfo

源码文件：

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git clone https://gitlab.freedesktop.org/mesa/demos.git

获取显存大小：queryInteger(GLX_RENDERER_VIDEO_MEMORY_MESA, v)

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queryInteger(GLX_RENDERER_ACCELERATED_MESA, v);
printf("    Accelerated: %s\n", *v ? "yes" : "no");
queryInteger(GLX_RENDERER_VIDEO_MEMORY_MESA, v);
printf("    Video memory: %dMB\n", *v);
queryInteger(GLX_RENDERER_UNIFIED_MEMORY_ARCHITECTURE_MESA, v);
printf("    Unified memory: %s\n", *v ? "yes" : "no");

file: glxinfo.c

mesa

queryInteger在mesa中的实现：

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glXQueryCurrentRendererIntegerMESA
  \->__glXQueryRendererInteger --- GLX_RENDERER_VIDEO_MEMORY_MESA
    -> psc->vtable->query_renderer_integer()
  • dri3
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    static const struct glx_screen_vtable dri3_screen_vtable = {
       .create_context         = dri3_create_context,
       .create_context_attribs = dri3_create_context_attribs,
       .query_renderer_integer = dri3_query_renderer_integer,
       .query_renderer_string  = dri3_query_renderer_string,
    };
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dri3_query_renderer_integer
 \-> dri2_convert_glx_query_renderer_attribs
    \/
  dri_attribute = __DRI2_RENDERER_VIDEO_MEMORY <--GLX_RENDERER_VIDEO_MEMORY_MESA
 \->psc->rendererQuery->queryInteger((psc->driScreen, dri_attribute, value)
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const __DRI2rendererQueryExtension dri2RendererQueryExtension = {
    .base = { __DRI2_RENDERER_QUERY, 1 },

    .queryInteger         = dri2_query_renderer_integer,
    .queryString          = dri2_query_renderer_string
};

fire: src/gallium/state_trackers/dri/dri_query_renderer.c

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dri2_query_renderer_integer
 \-> __DRI2_RENDERER_VIDEO_MEMORY
   > screen->base.screen->get_param(screen->base.screen, PIPE_CAP_VIDEO_MEMORY)
  • get_param接口是struct pipe_screen提供给驱动的接口，需要各个驱动自己实现。

virgl

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struct pipe_screen *
virgl_create_screen(struct virgl_winsys *vws)
{
   struct virgl_screen *screen = CALLOC_STRUCT(virgl_screen);

   screen->base.get_name = virgl_get_name;
   screen->base.get_vendor = virgl_get_vendor;
   screen->base.get_param = virgl_get_param;
   ...
}
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virgl_get_param <- PIPE_CAP_VIDEO_MEMORY
\-> {
      ...
      case PIPE_CAP_VIDEO_MEMORY:
      return 0;
    }

在virgl中没有实现显存接口，默认为0，无法通过glxinfo获取

在virgl中的部分其他参数是获取host端的参数，通过struct virgl_winsys结构体中的get_caps接口。

  • drm： DRM_IOCTL_VIRTGPU_GET_CAPS
  • vtest： VCMD_GET_CAPS+VCMD_GET_CAPS2

radeonsi

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void si_init_screen_get_functions(struct si_screen *sscreen)
{
  sscreen->b.get_name = si_get_name;
  sscreen->b.get_vendor = si_get_vendor;
  sscreen->b.get_device_vendor = si_get_device_vendor;
  sscreen->b.get_param = si_get_param;
  ...
}
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static int si_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
{
  switch (param) {
    case PIPE_CAP_VIDEO_MEMORY:
      return sscreen->info.vram_size >> 20;
  }
  ...
}

在Radeon驱动中通过drmCommandWriteRead接口获取DRM_RADEON_GEM_INFO中的配置参数

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/* Get GEM info. */
retval = drmCommandWriteRead(ws->fd, DRM_RADEON_GEM_INFO,
        &gem_info, sizeof(gem_info));