radv: add RADV_PERFTEST option to turn off gtt spilling

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/8107
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35355>

docs/envvars.rst

@@ -1411,6 +1411,8 @@ RADV driver environment variables
       disable FMASK compression on MSAA images (GFX6-GFX10.3)
    ``nogpl``
       disable VK_EXT_graphics_pipeline_library
+   ``nogttspill``
+      disable GTT spilling when allocating memory
    ``nohiz``
       disable HIZ for depthstencil images
    ``noibs``

src/amd/vulkan/radv_debug.h

@@ -95,6 +95,7 @@ enum {
    RADV_PERFTEST_NIR_CACHE = 1u << 14,
    RADV_PERFTEST_RT_WAVE_32 = 1u << 15,
    RADV_PERFTEST_VIDEO_ENCODE = 1u << 16,
+   RADV_PERFTEST_NO_GTT_SPILL = 1u << 17,
 };
 
 enum {

src/amd/vulkan/radv_instance.c

@@ -117,6 +117,7 @@ static const struct debug_control radv_perftest_options[] = {{"localbos", RADV_P
                                                              {"nircache", RADV_PERFTEST_NIR_CACHE},
                                                              {"rtwave32", RADV_PERFTEST_RT_WAVE_32},
                                                              {"video_encode", RADV_PERFTEST_VIDEO_ENCODE},
+                                                             {"nogttspill", RADV_PERFTEST_NO_GTT_SPILL},
                                                              {NULL, 0}};
 
 static const struct debug_control radv_trap_excp_options[] = {

src/amd/vulkan/winsys/amdgpu/radv_amdgpu_bo.c

@@ -470,7 +470,8 @@ radv_amdgpu_winsys_bo_create(struct radeon_winsys *_ws, uint64_t size, unsigned
        * e.g. Horizon Zero Dawn allocates more memory than we have
        * VRAM.
        */
-      request.preferred_heap |= AMDGPU_GEM_DOMAIN_GTT;
+      if (!(ws->perftest & RADV_PERFTEST_NO_GTT_SPILL))
+          request.preferred_heap |= AMDGPU_GEM_DOMAIN_GTT;
    }
 
    if (initial_domain & RADEON_DOMAIN_GTT)