vtest: add vtest_resource_busy_wait_nop for fuzzer

Let VTEST_FUZZER_FENCES control whether VCMD_RESOURCE_BUSY_WAIT waits or
not.  Fences are always created.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Ryan Neph <ryanneph@google.com>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>

vtest/vtest.h

@@ -74,6 +74,7 @@ int vtest_block_read(struct vtest_input *input, void *buf, int size);
 int vtest_buf_read(struct vtest_input *input, void *buf, int size);
 
 int vtest_resource_busy_wait(uint32_t length_dw);
+int vtest_resource_busy_wait_nop(uint32_t length_dw);
 int vtest_renderer_create_fence(void);
 int vtest_poll(void);
 

vtest/vtest_fuzzer.c

@@ -68,7 +68,7 @@ const char* __lsan_default_suppressions() {
 
 typedef int (*vtest_cmd_fptr_t)(uint32_t);
 
-static const vtest_cmd_fptr_t vtest_commands[] = {
+static vtest_cmd_fptr_t vtest_commands[] = {
    NULL /* CMD ids starts at 1 */,
    vtest_send_caps,
    vtest_create_resource,
@@ -76,7 +76,7 @@ static const vtest_cmd_fptr_t vtest_commands[] = {
    vtest_transfer_get_nop,
    vtest_transfer_put_nop,
    vtest_submit_cmd,
-   vtest_resource_busy_wait,
+   NULL, /* VCMD_RESOURCE_BUSY_WAIT is determined by VTEST_FUZZER_FENCES */
    NULL, /* VCMD_CREATE_RENDERER is a specific case */
    vtest_send_caps2,
    vtest_ping_protocol_version,
@@ -87,12 +87,15 @@ static const vtest_cmd_fptr_t vtest_commands[] = {
 };
 
 static void vtest_fuzzer_run_renderer(int out_fd, struct vtest_input *input,
-                                      int ctx_flags, bool create_fences)
+                                      int ctx_flags, bool wait_fences)
 {
    struct vtest_context *context = NULL;
    int ret;
    uint32_t header[VTEST_HDR_SIZE];
 
+   vtest_commands[VCMD_RESOURCE_BUSY_WAIT] = wait_fences ?
+      vtest_resource_busy_wait : vtest_resource_busy_wait_nop;
+
    do {
       ret = input->read(input, &header, sizeof(header));
       if (ret < 0 || (size_t)ret < sizeof(header)) {
@@ -135,8 +138,7 @@ static void vtest_fuzzer_run_renderer(int out_fd, struct vtest_input *input,
       }
 
       /* GL draws are fenced, while possible fence creations are too */
-      if (create_fences &&
-          (header[1] == VCMD_SUBMIT_CMD || header[1] == VCMD_RESOURCE_CREATE ||
+      if ((header[1] == VCMD_SUBMIT_CMD || header[1] == VCMD_RESOURCE_CREATE ||
            header[1] == VCMD_RESOURCE_CREATE2))
          vtest_renderer_create_fence();
    } while (1);

vtest/vtest_renderer.c

@@ -1414,6 +1414,30 @@ int vtest_resource_busy_wait(UNUSED uint32_t length_dw)
    return 0;
 }
 
+int vtest_resource_busy_wait_nop(UNUSED uint32_t length_dw)
+{
+   struct vtest_context *ctx = vtest_get_current_context();
+   uint32_t bw_buf[VCMD_BUSY_WAIT_SIZE];
+   uint32_t reply_buf[VTEST_HDR_SIZE + 1];
+   int ret;
+
+   ret = ctx->input->read(ctx->input, &bw_buf, sizeof(bw_buf));
+   if (ret != sizeof(bw_buf)) {
+      return -1;
+   }
+
+   reply_buf[VTEST_CMD_LEN] = 1;
+   reply_buf[VTEST_CMD_ID] = VCMD_RESOURCE_BUSY_WAIT;
+   reply_buf[VTEST_CMD_DATA_START] = 0;
+
+   ret = vtest_block_write(ctx->out_fd, reply_buf, sizeof(reply_buf));
+   if (ret < 0) {
+      return ret;
+   }
+
+   return 0;
+}
+
 int vtest_renderer_create_fence(void)
 {
    struct vtest_context *ctx = vtest_get_current_context();