radv: re-introduce DGC+multiview support and enable it for vkd3d-proton only

The Vulkan spec says:
    "VUID-vkCmdExecuteGeneratedCommandsEXT-None-11062
     If a rendering pass is currently active, the view mask must be 0."

So, it's invalid with VK_EXT_device_generated_commands but it's allowed
in DX12, it seems we missed this during the spec review.

Crimson Desert uses this and emulating in vkd3d-proton would be complex,
so let's re-introduce this support only for vkd3d-proton.

Cc: mesa-stable
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
(cherry picked from commit 782254b820)

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/41269>

.pick_status.json

@@ -1434,7 +1434,7 @@
         "description": "radv: re-introduce DGC+multiview support and enable it for vkd3d-proton only",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null,
         "notes": null

src/amd/vulkan/radv_cmd_buffer.c

@@ -13315,6 +13315,8 @@ radv_CmdExecuteGeneratedCommandsEXT(VkCommandBuffer commandBuffer, VkBool32 isPr
    VK_FROM_HANDLE(radv_indirect_execution_set, ies, pGeneratedCommandsInfo->indirectExecutionSet);
    VK_FROM_HANDLE(radv_cmd_buffer, cmd_buffer, commandBuffer);
    const struct radv_device *device = radv_cmd_buffer_device(cmd_buffer);
+   const struct radv_physical_device *pdev = radv_device_physical(device);
+   const struct radv_instance *instance = radv_physical_device_instance(pdev);
    const bool use_predication = radv_use_dgc_predication(cmd_buffer, pGeneratedCommandsInfo);
    const bool compute = !!(layout->vk.dgc_info & BITFIELD_BIT(MESA_VK_DGC_DISPATCH));
    const bool rt = !!(layout->vk.dgc_info & BITFIELD_BIT(MESA_VK_DGC_RT));
@@ -13413,7 +13415,22 @@ radv_CmdExecuteGeneratedCommandsEXT(VkCommandBuffer commandBuffer, VkBool32 isPr
       ac_emit_cp_pfp_sync_me(cs->b, cmd_buffer->state.predicating);
    }
 
-   radv_dgc_execute_ib(cmd_buffer, pGeneratedCommandsInfo);
+   /* The Vulkan spec 1.4.349 says:
+    *
+    * "VUID-vkCmdExecuteGeneratedCommandsEXT-None-11062
+    *  If a rendering pass is currently active, the view mask must be 0."
+    *
+    * But it's a valid behavior with DX12, so it can be enabled via drirc.
+    */
+   const uint32_t view_mask = instance->drirc.features.allow_dgc_multiview ? cmd_buffer->state.render.view_mask : 0;
+   if (rt || compute || !view_mask) {
+      radv_dgc_execute_ib(cmd_buffer, pGeneratedCommandsInfo);
+   } else {
+      u_foreach_bit (view, view_mask) {
+         radv_emit_view_index(&cmd_buffer->state, cmd_buffer->cs, view);
+         radv_dgc_execute_ib(cmd_buffer, pGeneratedCommandsInfo);
+      }
+   }
 
    if (rt) {
       cmd_buffer->push_constant_stages |= RADV_RT_STAGE_BITS;

src/amd/vulkan/radv_instance.c

@@ -206,6 +206,7 @@ static const driOptionDescription radv_dri_options[] = {
       DRI_CONF_RADV_EMULATE_RT(false)
       DRI_CONF_RADV_ENABLE_FLOAT16_GFX8(false)
       DRI_CONF_RADV_COOPERATIVE_MATRIX2_NV(false)
+      DRI_CONF_RADV_ALLOW_DGC_MULTIVIEW(false)
       DRI_CONF_RADV_WAIT_FOR_VM_MAP_UPDATES(false)
       DRI_CONF_RADV_NO_IMPLICIT_VARYING_SUBGROUP_SIZE(false)
       DRI_CONF_RADV_HIDE_REBAR_ON_DGPU(false)
@@ -278,6 +279,7 @@ radv_init_dri_features_options(struct radv_instance *instance)
    struct radv_drirc *drirc = &instance->drirc;
 
    drirc->features.cooperative_matrix2_nv = driQueryOptionb(&drirc->options, "radv_cooperative_matrix2_nv");
+   drirc->features.allow_dgc_multiview = driQueryOptionb(&drirc->options, "radv_allow_dgc_multiview");
    drirc->features.emulate_rt = driQueryOptionb(&drirc->options, "radv_emulate_rt");
    drirc->features.expose_float16_gfx8 = driQueryOptionb(&drirc->options, "radv_enable_float16_gfx8");
    drirc->features.vk_require_etc2 = driQueryOptionb(&drirc->options, "vk_require_etc2");

src/amd/vulkan/radv_instance.h

@@ -76,6 +76,7 @@ struct radv_drirc {
 
    struct {
       bool cooperative_matrix2_nv;
+      bool allow_dgc_multiview;
       bool emulate_rt;
       bool expose_float16_gfx8;
       bool vk_require_astc;

src/util/00-radv-defaults.conf

@@ -43,6 +43,7 @@ Application bugs worked around in this file:
             <option name="radv_disable_aniso_single_level" value="true" />
             <option name="radv_disable_trunc_coord" value="true" />
             <option name="radv_cooperative_matrix2_nv" value="true" />
+            <option name="radv_allow_dgc_multiview" value="true" />
         </engine>
 
         <engine engine_name_match="DXVK">

src/util/driconf.h

@@ -841,6 +841,10 @@
    DRI_CONF_OPT_B(radv_cooperative_matrix2_nv, def, \
                   "Expose VK_NV_cooperative_matrix2 on supported hardware.")
 
+#define DRI_CONF_RADV_ALLOW_DGC_MULTIVIEW(def) \
+   DRI_CONF_OPT_B(radv_allow_dgc_multiview, def, \
+                  "Allow to use DGC with multiview for DX12 emulation.")
+
 #define DRI_CONF_RADV_GFX12_HIZ_WA() \
    DRI_CONF_OPT_S_NODEF(radv_gfx12_hiz_wa, \
                         "Choose the specific HiZ workaround to apply on GFX12 (RDNA4). " \