OvmfPkg/VirtioFsDxe: implement EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume()

With the help of the VirtioFsFuseOpenDir() and
VirtioFsFuseReleaseFileOrDir() functions introduced previously, we can now
open and close the root directory. So let's implement
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume().

OpenVolume() creates a new EFI_FILE_PROTOCOL object -- a reference to the
root directory of the filesystem. Thus, we have to start tracking
references to EFI_SIMPLE_FILE_SYSTEM_PROTOCOL, lest we unbind the
virtio-fs device while files are open.

There are two methods that release an EFI_FILE_PROTOCOL object: the
Close() and the Delete() member functions. In particular, they are not
allowed to fail with regard to resource management -- they must release
resources unconditionally. Thus, for rolling back the resource accounting
that we do in EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume(), we have to
implement the first versions of EFI_FILE_PROTOCOL.Close() and
EFI_FILE_PROTOCOL.Delete() in this patch as well.

With this patch applied, the UEFI shell can enter the root directory of
the Virtio Filesystem (such as with the "FS3:" shell command), and the
"DIR" shell command exercises FUSE_OPENDIR and FUSE_RELEASEDIR, according
to the virtiofsd log. The "DIR" command reports the root directory as if
it were empty; probably because at this time, we only allow the shell to
open and to close the root directory, but not to read it.

Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-12-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

14 files changed, 427 insertions, 1 deletions

diff --git a/OvmfPkg/VirtioFsDxe/DriverBinding.c b/OvmfPkg/VirtioFsDxe/DriverBinding.c
index 4f77ffaa99..e273c9f362 100644
--- a/OvmfPkg/VirtioFsDxe/DriverBinding.c
+++ b/OvmfPkg/VirtioFsDxe/DriverBinding.c
@@ -95,6 +95,7 @@ VirtioFsBindingStart (
     goto UninitVirtioFs;

   }

 

+  InitializeListHead (&VirtioFs->OpenFiles);

   VirtioFs->SimpleFs.Revision   = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;

   VirtioFs->SimpleFs.OpenVolume = VirtioFsOpenVolume;

 

@@ -149,6 +150,10 @@ VirtioFsBindingStop (
 

   VirtioFs = VIRTIO_FS_FROM_SIMPLE_FS (SimpleFs);

 

+  if (!IsListEmpty (&VirtioFs->OpenFiles)) {

+    return EFI_ACCESS_DENIED;

+  }

+

   Status = gBS->UninstallProtocolInterface (ControllerHandle,

                   &gEfiSimpleFileSystemProtocolGuid, SimpleFs);

   if (EFI_ERROR (Status)) {

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsClose.c b/OvmfPkg/VirtioFsDxe/SimpleFsClose.c
new file mode 100644
index 0000000000..01bbeae214
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsClose.c
@@ -0,0 +1,48 @@
+/** @file

+  EFI_FILE_PROTOCOL.Close() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include <Library/BaseLib.h>             // RemoveEntryList()

+#include <Library/MemoryAllocationLib.h> // FreePool()

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileClose (

+  IN EFI_FILE_PROTOCOL *This

+  )

+{

+  VIRTIO_FS_FILE *VirtioFsFile;

+  VIRTIO_FS      *VirtioFs;

+

+  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);

+  VirtioFs     = VirtioFsFile->OwnerFs;

+

+  //

+  // At this point, the implementation is only suitable for closing the

+  // VIRTIO_FS_FILE that was created by VirtioFsOpenVolume().

+  //

+  ASSERT (VirtioFsFile->IsDirectory);

+  ASSERT (VirtioFsFile->NodeId == VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID);

+  //

+  // Close the root directory.

+  //

+  // Ignore any errors, because EFI_FILE_PROTOCOL.Close() is required to

+  // release the EFI_FILE_PROTOCOL object unconditionally.

+  //

+  VirtioFsFuseReleaseFileOrDir (VirtioFs, VirtioFsFile->NodeId,

+    VirtioFsFile->FuseHandle, VirtioFsFile->IsDirectory);

+

+  //

+  // One fewer file left open for the owner filesystem.

+  //

+  RemoveEntryList (&VirtioFsFile->OpenFilesEntry);

+

+  FreePool (VirtioFsFile);

+  return EFI_SUCCESS;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsDelete.c b/OvmfPkg/VirtioFsDxe/SimpleFsDelete.c
new file mode 100644
index 0000000000..3209923d1e
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsDelete.c
@@ -0,0 +1,29 @@
+/** @file

+  EFI_FILE_PROTOCOL.Delete() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileDelete (

+  IN EFI_FILE_PROTOCOL *This

+  )

+{

+  //

+  // At this point, the implementation is only suitable for closing the

+  // VIRTIO_FS_FILE that was created by VirtioFsOpenVolume().

+  //

+  // Actually deleting the root directory is not possible, so we're only going

+  // to release resources, and return EFI_WARN_DELETE_FAILURE.

+  //

+  // In order to release resources, VirtioFsSimpleFileClose() is just right

+  // here.

+  //

+  VirtioFsSimpleFileClose (This);

+  return EFI_WARN_DELETE_FAILURE;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsFlush.c b/OvmfPkg/VirtioFsDxe/SimpleFsFlush.c
new file mode 100644
index 0000000000..e48d92140f
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsFlush.c
@@ -0,0 +1,18 @@
+/** @file

+  EFI_FILE_PROTOCOL.Flush() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileFlush (

+  IN EFI_FILE_PROTOCOL *This

+  )

+{

+  return EFI_NO_MEDIA;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsGetInfo.c b/OvmfPkg/VirtioFsDxe/SimpleFsGetInfo.c
new file mode 100644
index 0000000000..6e870460c0
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsGetInfo.c
@@ -0,0 +1,21 @@
+/** @file

+  EFI_FILE_PROTOCOL.GetInfo() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileGetInfo (

+  IN     EFI_FILE_PROTOCOL *This,

+  IN     EFI_GUID          *InformationType,

+  IN OUT UINTN             *BufferSize,

+     OUT VOID              *Buffer

+  )

+{

+  return EFI_NO_MEDIA;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsGetPosition.c b/OvmfPkg/VirtioFsDxe/SimpleFsGetPosition.c
new file mode 100644
index 0000000000..2f40d2be26
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsGetPosition.c
@@ -0,0 +1,20 @@
+/** @file

+  EFI_FILE_PROTOCOL.GetPosition() member function for the Virtio Filesystem

+  driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileGetPosition (

+  IN     EFI_FILE_PROTOCOL *This,

+     OUT UINT64            *Position

+  )

+{

+  return EFI_DEVICE_ERROR;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c b/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c
new file mode 100644
index 0000000000..f0e2491840
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsOpen.c
@@ -0,0 +1,22 @@
+/** @file

+  EFI_FILE_PROTOCOL.Open() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileOpen (

+  IN     EFI_FILE_PROTOCOL *This,

+     OUT EFI_FILE_PROTOCOL **NewHandle,

+  IN     CHAR16            *FileName,

+  IN     UINT64            OpenMode,

+  IN     UINT64            Attributes

+  )

+{

+  return EFI_NO_MEDIA;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsOpenVolume.c b/OvmfPkg/VirtioFsDxe/SimpleFsOpenVolume.c
index a5a66a27d8..8c1457a68a 100644
--- a/OvmfPkg/VirtioFsDxe/SimpleFsOpenVolume.c
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsOpenVolume.c
@@ -7,6 +7,9 @@
   SPDX-License-Identifier: BSD-2-Clause-Patent

 **/

 

+#include <Library/BaseLib.h>             // InsertTailList()

+#include <Library/MemoryAllocationLib.h> // AllocatePool()

+

 #include "VirtioFsDxe.h"

 

 /**

@@ -22,5 +25,57 @@ VirtioFsOpenVolume (
   OUT EFI_FILE_PROTOCOL               **Root

   )

 {

-  return EFI_NO_MEDIA;

+  VIRTIO_FS      *VirtioFs;

+  VIRTIO_FS_FILE *VirtioFsFile;

+  EFI_STATUS     Status;

+  UINT64         RootDirHandle;

+

+  VirtioFs = VIRTIO_FS_FROM_SIMPLE_FS (This);

+

+  VirtioFsFile = AllocatePool (sizeof *VirtioFsFile);

+  if (VirtioFsFile == NULL) {

+    return EFI_OUT_OF_RESOURCES;

+  }

+

+  //

+  // Open the root directory.

+  //

+  Status = VirtioFsFuseOpenDir (VirtioFs, VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID,

+             &RootDirHandle);

+  if (EFI_ERROR (Status)) {

+    goto FreeVirtioFsFile;

+  }

+

+  //

+  // Populate the new VIRTIO_FS_FILE object.

+  //

+  VirtioFsFile->Signature              = VIRTIO_FS_FILE_SIG;

+  VirtioFsFile->SimpleFile.Revision    = EFI_FILE_PROTOCOL_REVISION;

+  VirtioFsFile->SimpleFile.Open        = VirtioFsSimpleFileOpen;

+  VirtioFsFile->SimpleFile.Close       = VirtioFsSimpleFileClose;

+  VirtioFsFile->SimpleFile.Delete      = VirtioFsSimpleFileDelete;

+  VirtioFsFile->SimpleFile.Read        = VirtioFsSimpleFileRead;

+  VirtioFsFile->SimpleFile.Write       = VirtioFsSimpleFileWrite;

+  VirtioFsFile->SimpleFile.GetPosition = VirtioFsSimpleFileGetPosition;

+  VirtioFsFile->SimpleFile.SetPosition = VirtioFsSimpleFileSetPosition;

+  VirtioFsFile->SimpleFile.GetInfo     = VirtioFsSimpleFileGetInfo;

+  VirtioFsFile->SimpleFile.SetInfo     = VirtioFsSimpleFileSetInfo;

+  VirtioFsFile->SimpleFile.Flush       = VirtioFsSimpleFileFlush;

+  VirtioFsFile->IsDirectory            = TRUE;

+  VirtioFsFile->OwnerFs                = VirtioFs;

+  VirtioFsFile->NodeId                 = VIRTIO_FS_FUSE_ROOT_DIR_NODE_ID;

+  VirtioFsFile->FuseHandle             = RootDirHandle;

+

+  //

+  // One more file open for the filesystem.

+  //

+  InsertTailList (&VirtioFs->OpenFiles, &VirtioFsFile->OpenFilesEntry);

+

+  *Root = &VirtioFsFile->SimpleFile;

+  return EFI_SUCCESS;

+

+FreeVirtioFsFile:

+  FreePool (VirtioFsFile);

+

+  return Status;

 }

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsRead.c b/OvmfPkg/VirtioFsDxe/SimpleFsRead.c
new file mode 100644
index 0000000000..e737d5e332
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsRead.c
@@ -0,0 +1,20 @@
+/** @file

+  EFI_FILE_PROTOCOL.Read() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileRead (

+  IN     EFI_FILE_PROTOCOL *This,

+  IN OUT UINTN             *BufferSize,

+     OUT VOID              *Buffer

+  )

+{

+  return EFI_NO_MEDIA;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c b/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c
new file mode 100644
index 0000000000..200b7a1bcd
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsSetInfo.c
@@ -0,0 +1,21 @@
+/** @file

+  EFI_FILE_PROTOCOL.SetInfo() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileSetInfo (

+  IN EFI_FILE_PROTOCOL *This,

+  IN EFI_GUID          *InformationType,

+  IN UINTN             BufferSize,

+  IN VOID              *Buffer

+  )

+{

+  return EFI_NO_MEDIA;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c b/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c
new file mode 100644
index 0000000000..ee8cb1f4e4
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c
@@ -0,0 +1,20 @@
+/** @file

+  EFI_FILE_PROTOCOL.SetPosition() member function for the Virtio Filesystem

+  driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileSetPosition (

+  IN EFI_FILE_PROTOCOL *This,

+  IN UINT64            Position

+  )

+{

+  return EFI_DEVICE_ERROR;

+}

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsWrite.c b/OvmfPkg/VirtioFsDxe/SimpleFsWrite.c
new file mode 100644
index 0000000000..90d82bd722
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsWrite.c
@@ -0,0 +1,20 @@
+/** @file

+  EFI_FILE_PROTOCOL.Write() member function for the Virtio Filesystem driver.

+

+  Copyright (C) 2020, Red Hat, Inc.

+

+  SPDX-License-Identifier: BSD-2-Clause-Patent

+**/

+

+#include "VirtioFsDxe.h"

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileWrite (

+  IN     EFI_FILE_PROTOCOL *This,

+  IN OUT UINTN             *BufferSize,

+  IN     VOID              *Buffer

+  )

+{

+  return EFI_NO_MEDIA;

+}

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index a99625d047..34574d0596 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -19,6 +19,9 @@
 

 #define VIRTIO_FS_SIG SIGNATURE_64 ('V', 'I', 'R', 'T', 'I', 'O', 'F', 'S')

 

+#define VIRTIO_FS_FILE_SIG \

+  SIGNATURE_64 ('V', 'I', 'O', 'F', 'S', 'F', 'I', 'L')

+

 //

 // Filesystem label encoded in UCS-2, transformed from the UTF-8 representation

 // in "VIRTIO_FS_CONFIG.Tag", and NUL-terminated. Only the printable ASCII code

@@ -46,6 +49,7 @@ typedef struct {
   VOID                            *RingMap;  // VirtioRingMap       2

   UINT64                          RequestId; // FuseInitSession     1

   EFI_EVENT                       ExitBoot;  // DriverBindingStart  0

+  LIST_ENTRY                      OpenFiles; // DriverBindingStart  0

   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL SimpleFs;  // DriverBindingStart  0

 } VIRTIO_FS;

 

@@ -99,6 +103,39 @@ typedef struct {
 } VIRTIO_FS_SCATTER_GATHER_LIST;

 

 //

+// Private context structure that exposes EFI_FILE_PROTOCOL on top of an open

+// FUSE file reference.

+//

+typedef struct {

+  UINT64            Signature;

+  EFI_FILE_PROTOCOL SimpleFile;

+  BOOLEAN           IsDirectory;

+  VIRTIO_FS         *OwnerFs;

+  LIST_ENTRY        OpenFilesEntry;

+  //

+  // In the FUSE wire protocol, every request except FUSE_INIT refers to a

+  // file, namely by the "VIRTIO_FS_FUSE_REQUEST.NodeId" field; that is, by the

+  // inode number of the file. However, some of the FUSE requests that we need

+  // for some of the EFI_FILE_PROTOCOL member functions require an open file

+  // handle *in addition* to the inode number. For simplicity, whenever a

+  // VIRTIO_FS_FILE object is created, primarily defined by its NodeId field,

+  // we also *open* the referenced file at once, and save the returned file

+  // handle in the FuseHandle field. This way, when an EFI_FILE_PROTOCOL member

+  // function must send a FUSE request that needs the file handle *in addition*

+  // to the inode number, FuseHandle will be at our disposal at once.

+  //

+  UINT64 NodeId;

+  UINT64 FuseHandle;

+} VIRTIO_FS_FILE;

+

+#define VIRTIO_FS_FILE_FROM_SIMPLE_FILE(SimpleFileReference) \

+  CR (SimpleFileReference, VIRTIO_FS_FILE, SimpleFile, VIRTIO_FS_FILE_SIG);

+

+#define VIRTIO_FS_FILE_FROM_OPEN_FILES_ENTRY(OpenFilesEntryReference) \

+  CR (OpenFilesEntryReference, VIRTIO_FS_FILE, OpenFilesEntry, \

+    VIRTIO_FS_FILE_SIG);

+

+//

 // Initialization and helper routines for the Virtio Filesystem device.

 //

 

@@ -190,4 +227,84 @@ VirtioFsOpenVolume (
   OUT EFI_FILE_PROTOCOL               **Root

   );

 

+//

+// EFI_FILE_PROTOCOL member functions for the Virtio Filesystem driver.

+//

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileClose (

+  IN EFI_FILE_PROTOCOL *This

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileDelete (

+  IN EFI_FILE_PROTOCOL *This

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileFlush (

+  IN EFI_FILE_PROTOCOL *This

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileGetInfo (

+  IN     EFI_FILE_PROTOCOL *This,

+  IN     EFI_GUID          *InformationType,

+  IN OUT UINTN             *BufferSize,

+     OUT VOID              *Buffer

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileGetPosition (

+  IN     EFI_FILE_PROTOCOL *This,

+     OUT UINT64            *Position

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileOpen (

+  IN     EFI_FILE_PROTOCOL *This,

+     OUT EFI_FILE_PROTOCOL **NewHandle,

+  IN     CHAR16            *FileName,

+  IN     UINT64            OpenMode,

+  IN     UINT64            Attributes

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileRead (

+  IN     EFI_FILE_PROTOCOL *This,

+  IN OUT UINTN             *BufferSize,

+     OUT VOID              *Buffer

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileSetInfo (

+  IN EFI_FILE_PROTOCOL *This,

+  IN EFI_GUID          *InformationType,

+  IN UINTN             BufferSize,

+  IN VOID              *Buffer

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileSetPosition (

+  IN EFI_FILE_PROTOCOL *This,

+  IN UINT64            Position

+  );

+

+EFI_STATUS

+EFIAPI

+VirtioFsSimpleFileWrite (

+  IN     EFI_FILE_PROTOCOL *This,

+  IN OUT UINTN             *BufferSize,

+  IN     VOID              *Buffer

+  );

+

 #endif // VIRTIO_FS_DXE_H_

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
index 95b1a5a8f6..28e66082ec 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
@@ -86,7 +86,17 @@
   FuseOpenDir.c

   FuseRelease.c

   Helpers.c

+  SimpleFsClose.c

+  SimpleFsDelete.c

+  SimpleFsFlush.c

+  SimpleFsGetInfo.c

+  SimpleFsGetPosition.c

+  SimpleFsOpen.c

   SimpleFsOpenVolume.c

+  SimpleFsRead.c

+  SimpleFsSetInfo.c

+  SimpleFsSetPosition.c

+  SimpleFsWrite.c

   VirtioFsDxe.h

 

 [LibraryClasses]