cyberus-technology · phip1611 · Apr 13, 2026
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsClose.c b/OvmfPkg/VirtioFsDxe/SimpleFsClose.c
@@ -19,9 +19,11 @@ VirtioFsSimpleFileClose (
 {
   VIRTIO_FS_FILE  *VirtioFsFile;
   VIRTIO_FS       *VirtioFs;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
   VirtioFs     = VirtioFsFile->OwnerFs;
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   //
   // All actions in this function are "best effort"; the UEFI spec requires
@@ -76,5 +78,6 @@ VirtioFsSimpleFileClose (
   }
 
   FreePool (VirtioFsFile);
+  VirtioFsReleaseLock (CurrentTpl);
   return EFI_SUCCESS;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsDelete.c b/OvmfPkg/VirtioFsDxe/SimpleFsDelete.c
@@ -20,9 +20,11 @@ VirtioFsSimpleFileDelete (
   VIRTIO_FS_FILE  *VirtioFsFile;
   VIRTIO_FS       *VirtioFs;
   EFI_STATUS      Status;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
   VirtioFs     = VirtioFsFile->OwnerFs;
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   //
   // All actions in this function are "best effort"; the UEFI spec requires
@@ -112,5 +114,6 @@ VirtioFsSimpleFileDelete (
   }
 
   FreePool (VirtioFsFile);
+  VirtioFsReleaseLock (CurrentTpl);
   return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsFlush.c b/OvmfPkg/VirtioFsDxe/SimpleFsFlush.c
@@ -17,11 +17,14 @@ VirtioFsSimpleFileFlush (
   VIRTIO_FS_FILE  *VirtioFsFile;
   VIRTIO_FS       *VirtioFs;
   EFI_STATUS      Status;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
   VirtioFs     = VirtioFsFile->OwnerFs;
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   if (!VirtioFsFile->IsOpenForWriting) {
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_ACCESS_DENIED;
   }
 
@@ -35,6 +38,7 @@ VirtioFsSimpleFileFlush (
                VirtioFsFile->FuseHandle
                );
     if (EFI_ERROR (Status)) {
+      VirtioFsReleaseLock (CurrentTpl);
       return Status;
     }
   }
@@ -45,5 +49,6 @@ VirtioFsSimpleFileFlush (
              VirtioFsFile->FuseHandle,
              VirtioFsFile->IsDirectory
              );
+  VirtioFsReleaseLock (CurrentTpl);
   return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsGetInfo.c b/OvmfPkg/VirtioFsDxe/SimpleFsGetInfo.c
@@ -208,17 +208,20 @@ VirtioFsSimpleFileGetInfo (
   OUT VOID                  *Buffer
   )
 {
-  if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {
-    return GetFileInfo (This, BufferSize, Buffer);
-  }
+  EFI_TPL     CurrentTpl;
+  EFI_STATUS  Status;
 
-  if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {
-    return GetFileSystemInfo (This, BufferSize, Buffer);
-  }
-
-  if (CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {
-    return GetFileSystemVolumeLabelInfo (This, BufferSize, Buffer);
+  CurrentTpl = VirtioFsAcquireLock ();
+  if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {
+    Status = GetFileInfo (This, BufferSize, Buffer);
+  } else if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {
+    Status = GetFileSystemInfo (This, BufferSize, Buffer);
+  } else if (CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {
+    Status = GetFileSystemVolumeLabelInfo (This, BufferSize, Buffer);
+  } else {
+    Status = EFI_UNSUPPORTED;
   }
 
-  return EFI_UNSUPPORTED;
+  VirtioFsReleaseLock (CurrentTpl);
+  return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsGetPosition.c b/OvmfPkg/VirtioFsDxe/SimpleFsGetPosition.c
@@ -17,12 +17,16 @@ VirtioFsSimpleFileGetPosition (
   )
 {
   VIRTIO_FS_FILE  *VirtioFsFile;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
+  CurrentTpl   = VirtioFsAcquireLock ();
   if (VirtioFsFile->IsDirectory) {
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_UNSUPPORTED;
   }
 
   *Position = VirtioFsFile->FilePosition;
+  VirtioFsReleaseLock (CurrentTpl);
   return EFI_SUCCESS;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c b/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c
@@ -329,9 +329,11 @@ VirtioFsSimpleFileOpen (
   UINT64          NewNodeId;
   UINT64          NewFuseHandle;
   BOOLEAN         NewNodeIsDirectory;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
   VirtioFs     = VirtioFsFile->OwnerFs;
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   //
   // Validate OpenMode.
@@ -350,6 +352,7 @@ VirtioFsSimpleFileOpen (
       PermitCreation = TRUE;
       break;
     default:
+      VirtioFsReleaseLock (CurrentTpl);
       return EFI_INVALID_PARAMETER;
   }
 
@@ -368,6 +371,7 @@ VirtioFsSimpleFileOpen (
       //
       // Unknown attribute requested.
       //
+      VirtioFsReleaseLock (CurrentTpl);
       return EFI_INVALID_PARAMETER;
     }
 
@@ -418,6 +422,7 @@ VirtioFsSimpleFileOpen (
       FileName
       ));
     if (!BugCompat) {
+      VirtioFsReleaseLock (CurrentTpl);
       return EFI_INVALID_PARAMETER;
     }
   }
@@ -427,6 +432,7 @@ VirtioFsSimpleFileOpen (
   //
   NewVirtioFsFile = AllocatePool (sizeof *NewVirtioFsFile);
   if (NewVirtioFsFile == NULL) {
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_OUT_OF_RESOURCES;
   }
 
@@ -456,7 +462,9 @@ VirtioFsSimpleFileOpen (
   if (AsciiStrCmp (NewCanonicalPath, "/") == 0) {
     FreePool (NewCanonicalPath);
     FreePool (NewVirtioFsFile);
-    return OpenRootDirectory (VirtioFs, NewHandle, OpenForWriting);
+    Status = OpenRootDirectory (VirtioFs, NewHandle, OpenForWriting);
+    VirtioFsReleaseLock (CurrentTpl);
+    return Status;
   }
 
   //
@@ -564,6 +572,7 @@ VirtioFsSimpleFileOpen (
   InsertTailList (&VirtioFs->OpenFiles, &NewVirtioFsFile->OpenFilesEntry);
 
   *NewHandle = &NewVirtioFsFile->SimpleFile;
+  VirtioFsReleaseLock (CurrentTpl);
   return EFI_SUCCESS;
 
 FreeNewCanonicalPath:
@@ -572,5 +581,6 @@ VirtioFsSimpleFileOpen (
 FreeNewVirtioFsFile:
   FreePool (NewVirtioFsFile);
 
+  VirtioFsReleaseLock (CurrentTpl);
   return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsOpenVolume.c b/OvmfPkg/VirtioFsDxe/SimpleFsOpenVolume.c
@@ -30,11 +30,14 @@ VirtioFsOpenVolume (
   EFI_STATUS      Status;
   CHAR8           *CanonicalPathname;
   UINT64          RootDirHandle;
+  EFI_TPL         CurrentTpl;
 
   VirtioFs = VIRTIO_FS_FROM_SIMPLE_FS (This);
+  CurrentTpl = VirtioFsAcquireLock ();
 
   VirtioFsFile = AllocatePool (sizeof *VirtioFsFile);
   if (VirtioFsFile == NULL) {
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_OUT_OF_RESOURCES;
   }
 
@@ -89,6 +92,7 @@ VirtioFsOpenVolume (
   InsertTailList (&VirtioFs->OpenFiles, &VirtioFsFile->OpenFilesEntry);
 
   *Root = &VirtioFsFile->SimpleFile;
+  VirtioFsReleaseLock (CurrentTpl);
   return EFI_SUCCESS;
 
 FreeCanonicalPathname:
@@ -97,5 +101,6 @@ VirtioFsOpenVolume (
 FreeVirtioFsFile:
   FreePool (VirtioFsFile);
 
+  VirtioFsReleaseLock (CurrentTpl);
   return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsRead.c b/OvmfPkg/VirtioFsDxe/SimpleFsRead.c
@@ -436,14 +436,17 @@ VirtioFsSimpleFileRead (
 {
   VIRTIO_FS_FILE  *VirtioFsFile;
   EFI_STATUS      Status;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   if (VirtioFsFile->IsDirectory) {
     Status = ReadFileInfoCache (VirtioFsFile, BufferSize, Buffer);
   } else {
     Status = ReadRegularFile (VirtioFsFile, BufferSize, Buffer);
   }
 
+  VirtioFsReleaseLock (CurrentTpl);
   return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c b/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c
@@ -625,17 +625,20 @@ VirtioFsSimpleFileSetInfo (
   IN VOID               *Buffer
   )
 {
-  if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {
-    return SetFileInfo (This, BufferSize, Buffer);
-  }
-
-  if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {
-    return SetFileSystemInfo (This, BufferSize, Buffer);
-  }
+  EFI_TPL     CurrentTpl;
+  EFI_STATUS  Status;
 
-  if (CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {
-    return SetFileSystemVolumeLabelInfo (This, BufferSize, Buffer);
+  CurrentTpl = VirtioFsAcquireLock ();
+  if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {
+    Status = SetFileInfo (This, BufferSize, Buffer);
+  } else if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {
+    Status = SetFileSystemInfo (This, BufferSize, Buffer);
+  } else if (CompareGuid (InformationType, &gEfiFileSystemVolumeLabelInfoIdGuid)) {
+    Status = SetFileSystemVolumeLabelInfo (This, BufferSize, Buffer);
+  } else {
+    Status = EFI_UNSUPPORTED;
   }
 
-  return EFI_UNSUPPORTED;
+  VirtioFsReleaseLock (CurrentTpl);
+  return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c b/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c
@@ -22,14 +22,17 @@ VirtioFsSimpleFileSetPosition (
   VIRTIO_FS                           *VirtioFs;
   EFI_STATUS                          Status;
   VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE  FuseAttr;
+  EFI_TPL                             CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   //
   // Directories can only be rewound, per spec.
   //
   if (VirtioFsFile->IsDirectory) {
     if (Position != 0) {
+      VirtioFsReleaseLock (CurrentTpl);
       return EFI_UNSUPPORTED;
     }
 
@@ -42,6 +45,7 @@ VirtioFsSimpleFileSetPosition (
     VirtioFsFile->SingleFileInfoSize = 0;
     VirtioFsFile->NumFileInfo        = 0;
     VirtioFsFile->NextFileInfo       = 0;
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_SUCCESS;
   }
 
@@ -53,6 +57,7 @@ VirtioFsSimpleFileSetPosition (
     // Caller is requesting absolute file position.
     //
     VirtioFsFile->FilePosition = Position;
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_SUCCESS;
   }
 
@@ -62,9 +67,11 @@ VirtioFsSimpleFileSetPosition (
   VirtioFs = VirtioFsFile->OwnerFs;
   Status   = VirtioFsFuseGetAttr (VirtioFs, VirtioFsFile->NodeId, &FuseAttr);
   if (EFI_ERROR (Status)) {
+    VirtioFsReleaseLock (CurrentTpl);
     return Status;
   }
 
   VirtioFsFile->FilePosition = FuseAttr.Size;
+  VirtioFsReleaseLock (CurrentTpl);
   return EFI_SUCCESS;
 }
diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsWrite.c b/OvmfPkg/VirtioFsDxe/SimpleFsWrite.c
@@ -21,15 +21,19 @@ VirtioFsSimpleFileWrite (
   EFI_STATUS      Status;
   UINTN           Transferred;
   UINTN           Left;
+  EFI_TPL         CurrentTpl;
 
   VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);
   VirtioFs     = VirtioFsFile->OwnerFs;
+  CurrentTpl   = VirtioFsAcquireLock ();
 
   if (VirtioFsFile->IsDirectory) {
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_UNSUPPORTED;
   }
 
   if (!VirtioFsFile->IsOpenForWriting) {
+    VirtioFsReleaseLock (CurrentTpl);
     return EFI_ACCESS_DENIED;
   }
 
@@ -80,5 +84,6 @@ VirtioFsSimpleFileWrite (
   // error. In other words, (Transferred > 0) is inconsequential for the return
   // value.
   //
+  VirtioFsReleaseLock (CurrentTpl);
   return Status;
 }
diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -14,6 +14,7 @@
 #include <Guid/FileInfo.h>             // EFI_FILE_INFO
 #include <IndustryStandard/VirtioFs.h> // VIRTIO_FS_TAG_BYTES
 #include <Library/DebugLib.h>          // CR()
+#include <Library/UefiBootServicesTableLib.h> // gBS
 #include <Protocol/SimpleFileSystem.h> // EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
 #include <Protocol/VirtioDevice.h>     // VIRTIO_DEVICE_PROTOCOL
 #include <Uefi/UefiBaseType.h>         // EFI_EVENT
@@ -183,6 +184,26 @@ typedef struct {
   CR (OpenFilesEntryReference, VIRTIO_FS_FILE, OpenFilesEntry, \
     VIRTIO_FS_FILE_SIG);
 
+STATIC
+inline
+EFI_TPL
+VirtioFsAcquireLock (
+  VOID
+  )
+{
+  return gBS->RaiseTPL (TPL_NOTIFY);
+}
+
+STATIC
+inline
+VOID
+VirtioFsReleaseLock (
+  IN EFI_TPL  PreviousTpl
+  )
+{
+  gBS->RestoreTPL (PreviousTpl);
+}
+
 //
 // Initialization and helper routines for the Virtio Filesystem device.
 //