iommu: Check iommufd is broken during runtime

Rather than checking whether IOMMUFD is broken or not in the constructor, this patch checks it everytime app. tries to get the IOMMU context. This is for cases that the target device is binded to `vfio-pci` driver in the middle of the app's runtime, not the very first time. Signed-off-by: Minwoo Im <[email protected]>
SamsungDS · Jul 18, 2024 · a51a97b · a51a97b
1 parent c8af2e2
commit a51a97b
Showing 1 changed file with 5 additions and 6 deletions.
diff --git a/src/iommu/context.c b/src/iommu/context.c
@@ -27,24 +27,23 @@
 #define IOVA_MAX_39BITS (1ULL << 39)
 
 #ifdef HAVE_VFIO_DEVICE_BIND_IOMMUFD
-static bool __iommufd_broken;
-
-static void __attribute__((constructor)) __check_iommufd_broken(void)
+static inline bool __iommufd_is_broken(void)
 {
 	struct stat sb;
 
 	if (stat("/dev/vfio/devices", &sb) || !S_ISDIR(sb.st_mode)) {
 		log_info("iommufd broken; probably missing CONFIG_VFIO_DEVICE_CDEV=y\n");
 
-		__iommufd_broken = true;
+		return true;
 	}
+	return false;
 }
 #endif
 
 struct iommu_ctx *iommu_get_default_context(void)
 {
 #ifdef HAVE_VFIO_DEVICE_BIND_IOMMUFD
-	if (__iommufd_broken)
+	if (__iommufd_is_broken())
 		goto fallback;
 
 	return iommufd_get_default_iommu_context();
@@ -57,7 +56,7 @@ struct iommu_ctx *iommu_get_default_context(void)
 struct iommu_ctx *iommu_get_context(const char *name)
 {
 #ifdef HAVE_VFIO_DEVICE_BIND_IOMMUFD
-	if (__iommufd_broken)
+	if (__iommufd_is_broken())
 		goto fallback;
 
 	return iommufd_get_iommu_context(name);