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>
2020-12-16 22:10:45 +01:00
parent e8a74c9a07
commit fa97e37282
6 changed files with 182 additions and 8 deletions
--- a/OvmfPkg/VirtioFsDxe/FuseInit.c
+++ 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;
+}