Check if amdgpu gpu_metrics can be read and do some sanity-checks

src/amdgpu.cpp

@@ -1,9 +1,37 @@
+#include <spdlog/spdlog.h>
 #include "amdgpu.h"
 #include "gpu.h"
 #include "cpu.h"
 
 std::string metrics_path = "";
 
+bool amdgpu_check_metrics(const std::string& path)
+{
+    metrics_table_header header {};
+    std::ifstream in(path, std::ios_base::binary);
+    if (!in.read((char*)&header, sizeof(header)))
+    {
+        SPDLOG_DEBUG("Failed to read '{}': {}", path, in.eof() ? "End of file" : strerror(errno));
+        return false;
+    }
+
+    switch (header.structure_size)
+    {
+        case 80: // v1_0, not naturally aligned
+        case 96: // v1_1
+        case 104: // v1_2
+        case sizeof(gpu_metrics_v1_3): // v2.0, v2.1
+        case sizeof(gpu_metrics_v2_2):
+            if (header.format_revision == 1 || header.format_revision == 2)
+                return true;
+        default:
+            break;
+    }
+
+    SPDLOG_WARN("Unsupported gpu_metrics version: {}.{}", header.format_revision, header.content_revision);
+    return false;
+}
+
 void amdgpu_get_metrics()
 {
 	if (!metrics_path.empty()){

src/amdgpu.h

@@ -139,5 +139,6 @@ struct gpu_metrics_v2_2 {
 	uint64_t			indep_throttle_status;
 };
 
+bool amdgpu_check_metrics(const std::string& path);
 extern void amdgpu_get_metrics();
-extern std::string metrics_path;
+extern std::string metrics_path;

src/overlay.cpp

@@ -663,7 +663,7 @@ void init_gpu_stats(uint32_t& vendorID, uint32_t reported_deviceID, overlay_para
          }
 
          std::string gpu_metrics_path = path + "/device/gpu_metrics";
-         if (file_exists(gpu_metrics_path)) {
+         if (amdgpu_check_metrics(gpu_metrics_path)) {
             gpu_metrics_exists = true;
             metrics_path = gpu_metrics_path;
             SPDLOG_DEBUG("Using gpu_metrics of {}", path);