venus: handle device probing properly.

Currently if you try to probe the virtio ICD on a non-virtio system
it will fail in CreateInstance which causes the loader to spit on the
screen.

However instance creation shouldn't fail, the driver should just
not enumerate any devices in this case. It's a bit tricky to ensure
this, but return instance and then handle instance destruction
and fail device enumeration.

Cc: mesa-stable
Reviewed-by: Ryan Neph
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32266>
(cherry picked from commit 25b8f4f714)

.pick_status.json

@@ -304,7 +304,7 @@
         "description": "venus: handle device probing properly.",
         "nominated": true,
         "nomination_type": 1,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null,
         "notes": null

src/virtio/vulkan/vn_instance.c

@@ -276,6 +276,7 @@ vn_CreateInstance(const VkInstanceCreateInfo *pCreateInfo,
       return vn_error(NULL, result);
    }
 
+   VkInstance instance_handle = vn_instance_to_handle(instance);
    /* ring_idx = 0 reserved for CPU timeline */
    instance->ring_idx_used_mask = 0x1;
 
@@ -294,6 +295,10 @@ vn_CreateInstance(const VkInstanceCreateInfo *pCreateInfo,
    }
 
    result = vn_instance_init_renderer(instance);
+   if (result == VK_ERROR_INITIALIZATION_FAILED) {
+      *pInstance = instance_handle;
+      return VK_SUCCESS;
+   }
    if (result != VK_SUCCESS)
       goto out_mtx_destroy;
 
@@ -333,7 +338,6 @@ vn_CreateInstance(const VkInstanceCreateInfo *pCreateInfo,
       local_create_info.pApplicationInfo = &local_app_info;
    }
 
-   VkInstance instance_handle = vn_instance_to_handle(instance);
    result = vn_call_vkCreateInstance(instance->ring.ring, pCreateInfo, NULL,
                                      &instance_handle);
    if (result != VK_SUCCESS)
@@ -407,16 +411,18 @@ vn_DestroyInstance(VkInstance _instance,
    mtx_destroy(&instance->physical_device.mutex);
    mtx_destroy(&instance->ring_idx_mutex);
 
-   vn_call_vkDestroyInstance(instance->ring.ring, _instance, NULL);
+   if (instance->renderer) {
+      vn_call_vkDestroyInstance(instance->ring.ring, _instance, NULL);
 
-   vn_instance_fini_ring(instance);
+      vn_instance_fini_ring(instance);
 
-   vn_renderer_shmem_pool_fini(instance->renderer,
-                               &instance->reply_shmem_pool);
+      vn_renderer_shmem_pool_fini(instance->renderer,
+                                  &instance->reply_shmem_pool);
 
-   vn_renderer_shmem_pool_fini(instance->renderer, &instance->cs_shmem_pool);
+      vn_renderer_shmem_pool_fini(instance->renderer, &instance->cs_shmem_pool);
 
-   vn_renderer_destroy(instance->renderer, alloc);
+      vn_renderer_destroy(instance->renderer, alloc);
+   }
 
    driDestroyOptionCache(&instance->dri_options);
    driDestroyOptionInfo(&instance->available_dri_options);

src/virtio/vulkan/vn_physical_device.c

@@ -1500,6 +1500,10 @@ enumerate_physical_devices(struct vn_instance *instance,
    struct vn_physical_device *physical_devs = NULL;
    VkResult result;
 
+   if (!instance->renderer) {
+       *out_count = 0;
+       return VK_SUCCESS;
+   }
    uint32_t count = 0;
    result = vn_call_vkEnumeratePhysicalDevices(
       ring, vn_instance_to_handle(instance), &count, NULL);