From 2009815d616f8d201e724e0c87f06cd7de8e8bec Mon Sep 17 00:00:00 2001
From: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Date: Thu, 23 Oct 2025 18:06:22 +0200
Subject: [PATCH] radv: add radv_wait_for_vm_map_updates drirc and enable for
 Forza Horizon 5

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/13321
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38031>
---
 src/amd/vulkan/radv_device_memory.c | 4 ++++
 src/amd/vulkan/radv_instance.c      | 2 ++
 src/amd/vulkan/radv_instance.h      | 1 +
 src/util/00-radv-defaults.conf      | 3 +++
 src/util/driconf.h                  | 4 ++++
 5 files changed, 14 insertions(+)

diff --git a/src/amd/vulkan/radv_device_memory.c b/src/amd/vulkan/radv_device_memory.c
index c31dba5bd65..0822dd23c8a 100644
--- a/src/amd/vulkan/radv_device_memory.c
+++ b/src/amd/vulkan/radv_device_memory.c
@@ -240,6 +240,10 @@ radv_alloc_memory(struct radv_device *device, const VkMemoryAllocateInfo *pAlloc
           radv_device_should_clear_vram(device))
          flags |= RADEON_FLAG_ZERO_VRAM;
 
+      /* Only apply the workaround for BOs created by the application, not by the driver. */
+      if (instance->drirc.debug.wait_for_vm_map_updates)
+         flags |= RADEON_FLAG_VM_UPDATE_WAIT;
+
       /* On GFX12, DCC is transparent to the userspace driver and PTE.DCC is
        * set per buffer allocation. Only VRAM can have DCC. When the kernel
        * moves a buffer from VRAM->GTT it decompresses. When the kernel moves
diff --git a/src/amd/vulkan/radv_instance.c b/src/amd/vulkan/radv_instance.c
index 66595b3e92c..41541d8c5a8 100644
--- a/src/amd/vulkan/radv_instance.c
+++ b/src/amd/vulkan/radv_instance.c
@@ -200,6 +200,7 @@ 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_WAIT_FOR_VM_MAP_UPDATES(false)
    DRI_CONF_SECTION_END
 };
 // clang-format on
@@ -235,6 +236,7 @@ radv_init_dri_debug_options(struct radv_instance *instance)
    drirc->debug.split_fma = driQueryOptionb(&drirc->options, "radv_split_fma");
    drirc->debug.ssbo_non_uniform = driQueryOptionb(&drirc->options, "radv_ssbo_non_uniform");
    drirc->debug.tex_non_uniform = driQueryOptionb(&drirc->options, "radv_tex_non_uniform");
+   drirc->debug.wait_for_vm_map_updates = driQueryOptionb(&drirc->options, "radv_wait_for_vm_map_updates");
    drirc->debug.zero_vram = driQueryOptionb(&drirc->options, "radv_zero_vram");
    drirc->debug.app_layer = driQueryOptionstr(&drirc->options, "radv_app_layer");
 
diff --git a/src/amd/vulkan/radv_instance.h b/src/amd/vulkan/radv_instance.h
index 9d63eff61b0..702b7b9d79d 100644
--- a/src/amd/vulkan/radv_instance.h
+++ b/src/amd/vulkan/radv_instance.h
@@ -57,6 +57,7 @@ struct radv_drirc {
       bool ssbo_non_uniform;
       bool tex_non_uniform;
       bool zero_vram;
+      bool wait_for_vm_map_updates;
       char *app_layer;
       int override_uniform_offset_alignment;
    } debug;
diff --git a/src/util/00-radv-defaults.conf b/src/util/00-radv-defaults.conf
index 56fb675fe52..cc74cf7d8a7 100644
--- a/src/util/00-radv-defaults.conf
+++ b/src/util/00-radv-defaults.conf
@@ -236,6 +236,9 @@ Application bugs worked around in this file:
             <!-- The full WA hurts performance too much, use the partial one
                  that seems fine overall. -->
             <option name="radv_gfx12_hiz_wa" value="partial" />
+            <!-- Force waiting for VM MAP updates at allocation time to
+                 workaround an use-before-alloc which causes GPU hangs. -->
+            <option name="radv_wait_for_vm_map_updates" value="true" />
         </application>
 
         <application name="Far Cry 2" application_name_match="FarCry2.exe">
diff --git a/src/util/driconf.h b/src/util/driconf.h
index 220804d8eaa..7b8c553dd59 100644
--- a/src/util/driconf.h
+++ b/src/util/driconf.h
@@ -759,6 +759,10 @@
    DRI_CONF_OPT_B(radv_rt_wave64, def, \
                   "Force wave64 in RT shaders")
 
+#define DRI_CONF_RADV_WAIT_FOR_VM_MAP_UPDATES(def) \
+   DRI_CONF_OPT_B(radv_wait_for_vm_map_updates, def, \
+                  "Wait for VM MAP updates at allocation time to mitigate use-before-alloc")
+
 /**
  * Overrides for forcing re-compilation of pipelines when RADV_BUILD_ID_OVERRIDE is enabled.
  * These need to be bumped every time a compiler bugfix is backported (up to 8 shader