OvmfPkg/VirtioFsDxe: implement the wrapper function for FUSE_OPENDIR

Add the VirtioFsFuseOpenDir() function, for sending the FUSE_OPENDIR
command to the Virtio Filesystem device.

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: <20201216211125.19496-10-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

4 files changed, 143 insertions, 0 deletions

diff --git a/OvmfPkg/Include/IndustryStandard/VirtioFs.h b/OvmfPkg/Include/IndustryStandard/VirtioFs.h
index 006e0f5deb..c481053255 100644
--- a/OvmfPkg/Include/IndustryStandard/VirtioFs.h
+++ b/OvmfPkg/Include/IndustryStandard/VirtioFs.h
@@ -81,6 +81,7 @@ typedef struct {
 //

 typedef enum {

   VirtioFsFuseOpInit        = 26,

+  VirtioFsFuseOpOpenDir     = 27,

 } VIRTIO_FS_FUSE_OPCODE;

 

 #pragma pack (1)

@@ -127,6 +128,20 @@ typedef struct {
   UINT16 MapAlignment;

   UINT32 Unused[8];

 } VIRTIO_FS_FUSE_INIT_RESPONSE;

+

+//

+// Headers for VirtioFsFuseOpOpenDir.

+//

+typedef struct {

+  UINT32 Flags;

+  UINT32 Unused;

+} VIRTIO_FS_FUSE_OPEN_REQUEST;

+

+typedef struct {

+  UINT64 FileHandle;

+  UINT32 OpenFlags;

+  UINT32 Padding;

+} VIRTIO_FS_FUSE_OPEN_RESPONSE;

 #pragma pack ()

 

 #endif // VIRTIO_FS_H_

diff --git a/OvmfPkg/VirtioFsDxe/FuseOpenDir.c b/OvmfPkg/VirtioFsDxe/FuseOpenDir.c
new file mode 100644
index 0000000000..eef522693c
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/FuseOpenDir.c
@@ -0,0 +1,120 @@
+/** @file

+  FUSE_OPENDIR wrapper for the Virtio Filesystem device.

+

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

+

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

+**/

+

+#include "VirtioFsDxe.h"

+

+/**

+  Send a FUSE_OPENDIR request to the Virtio Filesystem device, for opening a

+  directory.

+

+  The function may only be called after VirtioFsFuseInitSession() returns

+  successfully and before VirtioFsUninit() is called.

+

+  @param[in,out] VirtioFs  The Virtio Filesystem device to send the

+                           FUSE_OPENDIR request to. On output, the FUSE request

+                           counter "VirtioFs->RequestId" will have been

+                           incremented.

+

+  @param[in] NodeId        The inode number of the directory to open.

+

+  @param[out] FuseHandle   The open file handle returned by the Virtio

+                           Filesystem device.

+

+  @retval EFI_SUCCESS  The directory has been opened.

+

+  @return              The "errno" value mapped to an EFI_STATUS code, if the

+                       Virtio Filesystem device explicitly reported an error.

+

+  @return              Error codes propagated from VirtioFsSgListsValidate(),

+                       VirtioFsFuseNewRequest(), VirtioFsSgListsSubmit(),

+                       VirtioFsFuseCheckResponse().

+**/

+EFI_STATUS

+VirtioFsFuseOpenDir (

+  IN OUT VIRTIO_FS *VirtioFs,

+  IN     UINT64    NodeId,

+     OUT UINT64    *FuseHandle

+  )

+{

+  VIRTIO_FS_FUSE_REQUEST        CommonReq;

+  VIRTIO_FS_FUSE_OPEN_REQUEST   OpenReq;

+  VIRTIO_FS_IO_VECTOR           ReqIoVec[2];

+  VIRTIO_FS_SCATTER_GATHER_LIST ReqSgList;

+  VIRTIO_FS_FUSE_RESPONSE       CommonResp;

+  VIRTIO_FS_FUSE_OPEN_RESPONSE  OpenResp;

+  VIRTIO_FS_IO_VECTOR           RespIoVec[2];

+  VIRTIO_FS_SCATTER_GATHER_LIST RespSgList;

+  EFI_STATUS                    Status;

+

+  //

+  // Set up the scatter-gather lists.

+  //

+  ReqIoVec[0].Buffer = &CommonReq;

+  ReqIoVec[0].Size   = sizeof CommonReq;

+  ReqIoVec[1].Buffer = &OpenReq;

+  ReqIoVec[1].Size   = sizeof OpenReq;

+  ReqSgList.IoVec    = ReqIoVec;

+  ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);

+

+  RespIoVec[0].Buffer = &CommonResp;

+  RespIoVec[0].Size   = sizeof CommonResp;

+  RespIoVec[1].Buffer = &OpenResp;

+  RespIoVec[1].Size   = sizeof OpenResp;

+  RespSgList.IoVec    = RespIoVec;

+  RespSgList.NumVec   = ARRAY_SIZE (RespIoVec);

+

+  //

+  // Validate the scatter-gather lists; calculate the total transfer sizes.

+  //

+  Status = VirtioFsSgListsValidate (VirtioFs, &ReqSgList, &RespSgList);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Populate the common request header.

+  //

+  Status = VirtioFsFuseNewRequest (VirtioFs, &CommonReq, ReqSgList.TotalSize,

+             VirtioFsFuseOpOpenDir, NodeId);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Populate the FUSE_OPENDIR-specific fields.

+  //

+  OpenReq.Flags  = 0;

+  OpenReq.Unused = 0;

+

+  //

+  // Submit the request.

+  //

+  Status = VirtioFsSgListsSubmit (VirtioFs, &ReqSgList, &RespSgList);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Verify the response (all response buffers are fixed size).

+  //

+  Status = VirtioFsFuseCheckResponse (&RespSgList, CommonReq.Unique, NULL);

+  if (EFI_ERROR (Status)) {

+    if (Status == EFI_DEVICE_ERROR) {

+      DEBUG ((DEBUG_ERROR, "%a: Label=\"%s\" NodeId=%Lu Errno=%d\n",

+        __FUNCTION__, VirtioFs->Label, NodeId, CommonResp.Error));

+      Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);

+    }

+    return Status;

+  }

+

+  //

+  // Output the open file handle.

+  //

+  *FuseHandle = OpenResp.FileHandle;

+  return EFI_SUCCESS;

+}

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index b8d4640118..9c47454435 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -163,6 +163,13 @@ VirtioFsFuseInitSession (
   IN OUT VIRTIO_FS *VirtioFs

   );

 

+EFI_STATUS

+VirtioFsFuseOpenDir (

+  IN OUT VIRTIO_FS *VirtioFs,

+  IN     UINT64    NodeId,

+     OUT UINT64    *FuseHandle

+  );

+

 //

 // EFI_SIMPLE_FILE_SYSTEM_PROTOCOL member functions for the Virtio Filesystem

 // driver.

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
index 8fddc50318..051acbdd71 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
@@ -83,6 +83,7 @@
 [Sources]

   DriverBinding.c

   FuseInit.c

+  FuseOpenDir.c

   Helpers.c

   SimpleFsOpenVolume.c

   VirtioFsDxe.h