kk: Support nullDescriptor

Add handling for null images and vertex inputs.

Reviewed-by: Aitor Camacho <aitor@lunarg.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/41313>

src/kosmickrisp/vulkan/kk_cmd_draw.c

@@ -552,7 +552,7 @@ kk_CmdBindVertexBuffers2(VkCommandBuffer commandBuffer, uint32_t firstBinding,
       const struct kk_addr_range addr_range =
          kk_buffer_addr_range(buffer, pOffsets[i], size);
       cmd->state.gfx.vb.addr_range[idx] = addr_range;
-      cmd->state.gfx.vb.handles[idx] = buffer->mtl_handle;
+      cmd->state.gfx.vb.handles[idx] = buffer ? buffer->mtl_handle : NULL;
       cmd->state.gfx.dirty |= KK_DIRTY_VB;
    }
 }

src/kosmickrisp/vulkan/kk_nir_lower_null_images.c

@@ -0,0 +1,107 @@
+/*
+ * Copyright © 2025 Imagination Technologies Ltd.
+ * Copyright (C) 2020-2021 Collabora, Ltd.
+ * Copyright © 2020 Valve Corporation
+ * Copyright 2026 LunarG, Inc.
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: MIT
+ */
+#include "kk_shader.h"
+
+#include "compiler/nir/nir.h"
+#include "compiler/nir/nir_builder.h"
+
+static nir_def*
+tex_handle_to_resource_id(nir_builder *b, nir_def* handle)
+{
+   /* Work backwards from the handle to the descriptor address it was loaded
+    * from, and load the plain resource ID */
+   const nir_instr *instr = nir_def_instr_const(handle);
+   nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
+   return nir_load_global_constant(b, 1, 64, intr->src[0].ssa);
+}
+
+static nir_def*
+get_is_null(nir_builder *b, nir_instr *instr, nir_def **def)
+{
+   *def = NULL;
+   nir_def *handle = NULL;
+
+   if (instr->type == nir_instr_type_intrinsic) {
+      nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
+      switch (intr->intrinsic) {
+      case nir_intrinsic_bindless_image_load:
+      case nir_intrinsic_bindless_image_sparse_load:
+      case nir_intrinsic_bindless_image_store:
+      case nir_intrinsic_bindless_image_atomic:
+      case nir_intrinsic_bindless_image_atomic_swap:
+      case nir_intrinsic_bindless_image_size:
+      case nir_intrinsic_bindless_image_samples:
+      case nir_intrinsic_bindless_image_levels:
+         if (nir_intrinsic_infos[intr->intrinsic].has_dest)
+            *def = &intr->def;
+
+         handle = intr->src[0].ssa;
+         break;
+
+      default:
+         break;
+      }
+   } else if (instr->type == nir_instr_type_tex) {
+      nir_tex_instr *tex = nir_instr_as_tex(instr);
+      *def = &tex->def;
+
+      handle = nir_get_tex_src(tex, nir_tex_src_texture_handle);
+   }
+
+   if (!handle)
+      return NULL;
+
+   nir_def* resource_id = tex_handle_to_resource_id(b, handle);
+   return nir_ieq_imm(b, resource_id, 0);
+}
+
+static bool
+lower(nir_builder *b, nir_instr *instr, UNUSED void *data)
+{
+   b->cursor = nir_before_instr(instr);
+
+   nir_def *def;
+   nir_def *is_null = get_is_null(b, instr, &def);
+
+   if (!is_null)
+      return false;
+
+   nir_def *zero = NULL;
+   nir_if *nif = nir_push_if(b, nir_inot(b, is_null));
+   nir_instr_remove(instr);
+   nir_builder_instr_insert(b, instr);
+   if (def) {
+      nir_push_else(b, nif);
+      zero = nir_imm_zero(b, def->num_components, def->bit_size);
+   }
+   nir_pop_if(b, nif);
+
+   if (def) {
+      nir_def *phi = nir_if_phi(b, def, zero);
+
+      /* We can't use nir_def_rewrite_uses_after on phis, so use the global
+       * version and fixup the phi manually
+       */
+      nir_def_rewrite_uses(def, phi);
+
+      nir_instr *phi_instr = nir_def_instr(phi);
+      nir_phi_instr *phi_as_phi = nir_instr_as_phi(phi_instr);
+      nir_phi_src *phi_src =
+         nir_phi_get_src_from_block(phi_as_phi, instr->block);
+      nir_src_rewrite(&phi_src->src, def);
+   }
+
+   return true;
+}
+
+bool kk_nir_lower_null_images(nir_shader *shader)
+{
+   return nir_shader_instructions_pass(shader, lower,
+                                       nir_metadata_none, NULL);
+}

src/kosmickrisp/vulkan/kk_shader.c

@@ -182,6 +182,9 @@ kk_hash_graphics_state(struct vk_physical_device *device,
                           sizeof(state->mv->view_mask));
    }
 
+   _mesa_blake3_update(&blake3_ctx, &enabled_features->nullDescriptor,
+                       sizeof(enabled_features->nullDescriptor));
+
    _mesa_blake3_final(&blake3_ctx, blake3_out);
 }
 
@@ -585,6 +588,9 @@ kk_lower_nir(struct kk_device *dev, nir_shader *nir,
             set_layouts);
    NIR_PASS(_, nir, kk_nir_lower_textures);
 
+   if (dev->vk.enabled_features.nullDescriptor)
+      NIR_PASS(_, nir, kk_nir_lower_null_images);
+
    NIR_PASS(_, nir, nir_lower_global_vars_to_local);
 }
 

src/kosmickrisp/vulkan/kk_shader.h

@@ -108,6 +108,8 @@ kk_nir_lower_descriptors(nir_shader *nir,
                          uint32_t set_layout_count,
                          struct vk_descriptor_set_layout *const *set_layouts);
 
+bool kk_nir_lower_null_images(nir_shader *nir);
+
 bool kk_nir_lower_textures(nir_shader *nir);
 
 bool kk_nir_lower_vs_multiview(nir_shader *nir, uint32_t view_mask);

src/kosmickrisp/vulkan/meson.build

@@ -80,6 +80,7 @@ kk_files = files(
   'kk_instance.c',
   'kk_nir_lower_descriptors.c',
   'kk_nir_lower_multiview.c',
+  'kk_nir_lower_null_images.c',
   'kk_nir_lower_textures.c',
   'kk_nir_lower_vbo.h',
   'kk_nir_lower_vbo.c',