anv/cmd_buffer: add a status field to anv_batch

The vkCmd*() functions do not report errors, instead, any errors should be
reported by the time we call vkEndCommandBuffer(). This means that we
need to make the driver robust against incosistent and/or imcomplete
command  buffer states through the command recording process, particularly,
avoid crashes due to access to memory that we failed to allocate previously.

The strategy used to do this is to track the first error ocurred while
recording a command buffer in the batch associated with it. We use the
batch to track this information because the command buffer may not be
visible to all parts of the driver that can produce errors we need to be
aware of (such as allocation failures during batch emissions).

Later patches will use this error information to guard parts of the driver
that may not be safe to execute.

v2: Move the field from the command buffer to the batch so we can track
    errors from batch emissions (Jason)

v3: Registering errors in the command buffer's batch during
    anv_create_cmd_buffer() is unnecessary, since the command buffer
    is freed at the end of the function in that case (Topi)

Reviewed-by: Topi Pohjolainen <[email protected]>

2 files changed, 13 insertions, 0 deletions

diff --git a/src/intel/vulkan/anv_cmd_buffer.c b/src/intel/vulkan/anv_cmd_buffer.c
index a6ad48a8627..b3fd02fef53 100644
--- a/src/intel/vulkan/anv_cmd_buffer.c
+++ b/src/intel/vulkan/anv_cmd_buffer.c
@@ -117,6 +117,8 @@ anv_cmd_state_reset(struct anv_cmd_buffer *cmd_buffer)
 {
    struct anv_cmd_state *state = &cmd_buffer->state;
 
+   cmd_buffer->batch.status = VK_SUCCESS;
+
    memset(&state->descriptors, 0, sizeof(state->descriptors));
    memset(&state->push_constants, 0, sizeof(state->push_constants));
    memset(state->binding_tables, 0, sizeof(state->binding_tables));
@@ -185,6 +187,8 @@ static VkResult anv_create_cmd_buffer(
    if (cmd_buffer == NULL)
       return vk_error(VK_ERROR_OUT_OF_HOST_MEMORY);
 
+   cmd_buffer->batch.status = VK_SUCCESS;
+
    cmd_buffer->_loader_data.loaderMagic = ICD_LOADER_MAGIC;
    cmd_buffer->device = device;
    cmd_buffer->pool = pool;
diff --git a/src/intel/vulkan/anv_private.h b/src/intel/vulkan/anv_private.h
index eec1cd6f8d0..fbf62255c1c 100644
--- a/src/intel/vulkan/anv_private.h
+++ b/src/intel/vulkan/anv_private.h
@@ -704,6 +704,15 @@ struct anv_batch {
     */
    VkResult (*extend_cb)(struct anv_batch *, void *);
    void *                                       user_data;
+
+   /**
+    * Current error status of the command buffer. Used to track inconsistent
+    * or incomplete command buffer states that are the consequence of run-time
+    * errors such as out of memory scenarios. We want to track this in the
+    * batch because the command buffer object is not visible to some parts
+    * of the driver.
+    */
+   VkResult                                     status;
 };
 
 void *anv_batch_emit_dwords(struct anv_batch *batch, int num_dwords);