diff options
Diffstat (limited to 'OvmfPkg/VirtioFsDxe/FuseInit.c')
| -rw-r--r-- | OvmfPkg/VirtioFsDxe/FuseInit.c | 132 |
1 files changed, 132 insertions, 0 deletions
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;
+}
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