Mesa (main): venus: Don't encode ignored pTessellationState

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Module: Mesa
Branch: main
Commit: fe3e850dfb2176e41ea6413b6739ae12cc4d32f7
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=fe3e850dfb2176e41ea6413b6739ae12cc4d32f7

Author: Chad Versace <chad at kiwitree.net>
Date:   Mon May  2 12:56:24 2022 -0700

venus: Don't encode ignored pTessellationState

The spec says that VkGraphicsPipelineCreateInfo::pTessellationState is
ignored and may be an invalid pointer in some cases. When ignored,
patch the pCreateInfo with `pTessellationState = NULL`, so the encoder
doesn't attempt to encode an invalid pointer.

Tested in Borealis, with debug build of venus, with a minimal test app
that sets `.pTesselationState = 0x17`. Pre-patch, the app crashes;
post-patch, the app works.

Signed-off-by: Chad Versace <chadversary at chromium.org>
Reviewed-by: Yiwei Zhang <zzyiwei at chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16284>

---

 src/virtio/vulkan/vn_pipeline.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/virtio/vulkan/vn_pipeline.c b/src/virtio/vulkan/vn_pipeline.c
index dbab41c7272..a5b45ce5504 100644
--- a/src/virtio/vulkan/vn_pipeline.c
+++ b/src/virtio/vulkan/vn_pipeline.c
@@ -242,6 +242,8 @@ vn_MergePipelineCaches(VkDevice device,
 /* pipeline commands */
 
 struct vn_graphics_pipeline_create_info_fix {
+   bool ignore_tessellation_state;
+
    /* Ignore the following:
     *    pViewportState
     *    pMultisampleState
@@ -269,6 +271,21 @@ vn_fix_graphics_pipeline_create_info(
       struct vn_graphics_pipeline_create_info_fix fix = { 0 };
       bool any_fix = false;
 
+      VkShaderStageFlags stages = 0;
+      for (uint32_t i = 0; i < info->stageCount; ++i) {
+         stages |= info->pStages[i].stage;
+      }
+
+      /* Fix pTessellationState?
+       *    VUID-VkGraphicsPipelineCreateInfo-pStages-00731
+       */
+      if (info->pTessellationState &&
+          (!(stages & VK_SHADER_STAGE_TESSELLATION_CONTROL_BIT) ||
+           !(stages & VK_SHADER_STAGE_TESSELLATION_EVALUATION_BIT))) {
+         fix.ignore_tessellation_state = true;
+         any_fix = true;
+      }
+
       /* FIXME: Conditions for ignoring pDepthStencilState and
        * pColorBlendState miss some cases that depend on the render pass. Make
        * them agree with the VUIDs.
@@ -311,6 +328,9 @@ vn_fix_graphics_pipeline_create_info(
       VkGraphicsPipelineCreateInfo *info = &infos[i];
       struct vn_graphics_pipeline_create_info_fix fix = fixes[i];
 
+      if (fix.ignore_tessellation_state)
+         info->pTessellationState = NULL;
+
       if (fix.ignore_raster_dedicated_states) {
          info->pViewportState = NULL;
          info->pMultisampleState = NULL;