OvmfPkg/VirtioFsDxe: submit the FUSE_INIT request to the device

Submit the FUSE_INIT request to the Virtio Filesystem device, for starting
the FUSE session.

The FUSE_INIT request is logged by the virtio-fs daemon, with this patch
applied, when (for example) using the "CONNECT" UEFI shell command.

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: <20201216211125.19496-9-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>

5 files changed, 151 insertions, 8 deletions

diff --git a/OvmfPkg/VirtioFsDxe/DriverBinding.c b/OvmfPkg/VirtioFsDxe/DriverBinding.c
index 4a2787a50a..4f77ffaa99 100644
--- a/OvmfPkg/VirtioFsDxe/DriverBinding.c
+++ b/OvmfPkg/VirtioFsDxe/DriverBinding.c
@@ -84,10 +84,10 @@ VirtioFsBindingStart (
     goto CloseVirtio;

   }

 

-  //

-  // Initialize the FUSE request counter.

-  //

-  VirtioFs->RequestId = 1;

+  Status = VirtioFsFuseInitSession (VirtioFs);

+  if (EFI_ERROR (Status)) {

+    goto UninitVirtioFs;

+  }

 

   Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_CALLBACK,

                   VirtioFsExitBoot, VirtioFs, &VirtioFs->ExitBoot);

diff --git a/OvmfPkg/VirtioFsDxe/FuseInit.c b/OvmfPkg/VirtioFsDxe/FuseInit.c
new file mode 100644
index 0000000000..aa19dbdc05
--- /dev/null
+++ b/OvmfPkg/VirtioFsDxe/FuseInit.c
@@ -0,0 +1,132 @@
+/** @file

+  FUSE_INIT 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_INIT request to the Virtio Filesystem device, for starting the

+  FUSE session.

+

+  From virtio-v1.1-cs01-87fa6b5d8155, 5.11.5 Device Initialization: "On

+  initialization the driver first discovers the device's virtqueues. The FUSE

+  session is started by sending a FUSE_INIT request as defined by the FUSE

+  protocol on one request virtqueue."

+

+  The function may only be called after VirtioFsInit() returns successfully and

+  before VirtioFsUninit() is called.

+

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

+                           request to. The FUSE request counter

+                           "VirtioFs->RequestId" is set to 1 on output.

+

+  @retval EFI_SUCCESS      The FUSE session has been started.

+

+  @retval EFI_UNSUPPORTED  FUSE interface version negotiation failed.

+

+  @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

+VirtioFsFuseInitSession (

+  IN OUT VIRTIO_FS *VirtioFs

+  )

+{

+  VIRTIO_FS_FUSE_REQUEST        CommonReq;

+  VIRTIO_FS_FUSE_INIT_REQUEST   InitReq;

+  VIRTIO_FS_IO_VECTOR           ReqIoVec[2];

+  VIRTIO_FS_SCATTER_GATHER_LIST ReqSgList;

+  VIRTIO_FS_FUSE_RESPONSE       CommonResp;

+  VIRTIO_FS_FUSE_INIT_RESPONSE  InitResp;

+  VIRTIO_FS_IO_VECTOR           RespIoVec[2];

+  VIRTIO_FS_SCATTER_GATHER_LIST RespSgList;

+  EFI_STATUS                    Status;

+

+  //

+  // Initialize the FUSE request counter.

+  //

+  VirtioFs->RequestId = 1;

+

+  //

+  // Set up the scatter-gather lists.

+  //

+  ReqIoVec[0].Buffer = &CommonReq;

+  ReqIoVec[0].Size   = sizeof CommonReq;

+  ReqIoVec[1].Buffer = &InitReq;

+  ReqIoVec[1].Size   = sizeof InitReq;

+  ReqSgList.IoVec    = ReqIoVec;

+  ReqSgList.NumVec   = ARRAY_SIZE (ReqIoVec);

+

+  RespIoVec[0].Buffer = &CommonResp;

+  RespIoVec[0].Size   = sizeof CommonResp;

+  RespIoVec[1].Buffer = &InitResp;

+  RespIoVec[1].Size   = sizeof InitResp;

+  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,

+             VirtioFsFuseOpInit, 0);

+  if (EFI_ERROR (Status)) {

+    return Status;

+  }

+

+  //

+  // Populate the FUSE_INIT-specific fields.

+  //

+  InitReq.Major        = VIRTIO_FS_FUSE_MAJOR;

+  InitReq.Minor        = VIRTIO_FS_FUSE_MINOR;

+  InitReq.MaxReadahead = 0;

+  InitReq.Flags        = 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\" Errno=%d\n", __FUNCTION__,

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

+      Status = VirtioFsErrnoToEfiStatus (CommonResp.Error);

+    }

+    return Status;

+  }

+

+  //

+  // Check FUSE interface version compatibility.

+  //

+  if (InitResp.Major < InitReq.Major ||

+      (InitResp.Major == InitReq.Major && InitResp.Minor < InitReq.Minor)) {

+    return EFI_UNSUPPORTED;

+  }

+

+  return EFI_SUCCESS;

+}

diff --git a/OvmfPkg/VirtioFsDxe/Helpers.c b/OvmfPkg/VirtioFsDxe/Helpers.c
index b408913186..739b0c63cf 100644
--- a/OvmfPkg/VirtioFsDxe/Helpers.c
+++ b/OvmfPkg/VirtioFsDxe/Helpers.c
@@ -721,7 +721,8 @@ Unmap:
                           to send.

 

   @param[in] NodeId       The inode number of the file that the request refers

-                          to.

+                          to. When Opcode is VirtioFsFuseOpInit, NodeId is

+                          ignored by the Virtio Filesystem device.

 

   @retval EFI_INVALID_PARAMETER  RequestSize is smaller than

                                  sizeof(VIRTIO_FS_FUSE_REQUEST).

@@ -737,7 +738,7 @@ VirtioFsFuseNewRequest (
   IN OUT VIRTIO_FS              *VirtioFs,

      OUT VIRTIO_FS_FUSE_REQUEST *Request,

   IN     UINT32                 RequestSize,

-  IN     UINT32                 Opcode,

+  IN     VIRTIO_FS_FUSE_OPCODE  Opcode,

   IN     UINT64                 NodeId

   )

 {

diff --git a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
index 772ab743cc..b8d4640118 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.h
@@ -44,7 +44,7 @@ typedef struct {
   UINT16                          QueueSize; // VirtioFsInit        1

   VRING                           Ring;      // VirtioRingInit      2

   VOID                            *RingMap;  // VirtioRingMap       2

-  UINT64                          RequestId; // DriverBindingStart  0

+  UINT64                          RequestId; // FuseInitSession     1

   EFI_EVENT                       ExitBoot;  // DriverBindingStart  0

   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL SimpleFs;  // DriverBindingStart  0

 } VIRTIO_FS;

@@ -138,7 +138,7 @@ VirtioFsFuseNewRequest (
   IN OUT VIRTIO_FS              *VirtioFs,

      OUT VIRTIO_FS_FUSE_REQUEST *Request,

   IN     UINT32                 RequestSize,

-  IN     UINT32                 Opcode,

+  IN     VIRTIO_FS_FUSE_OPCODE  Opcode,

   IN     UINT64                 NodeId

   );

 

@@ -155,6 +155,15 @@ VirtioFsErrnoToEfiStatus (
   );

 

 //

+// Wrapper functions for FUSE commands (primitives).

+//

+

+EFI_STATUS

+VirtioFsFuseInitSession (

+  IN OUT VIRTIO_FS *VirtioFs

+  );

+

+//

 // 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 f6eebdb6bc..8fddc50318 100644
--- a/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
+++ b/OvmfPkg/VirtioFsDxe/VirtioFsDxe.inf
@@ -82,6 +82,7 @@
 

 [Sources]

   DriverBinding.c

+  FuseInit.c

   Helpers.c

   SimpleFsOpenVolume.c

   VirtioFsDxe.h