Drivers: hv: Implement the file copy service

Implement the file copy service for Linux guests on Hyper-V. This permits the
host to copy a file (over VMBUS) into the guest. This facility is part of
"guest integration services" supported on the Windows platform.
Here is a link that provides additional details on this functionality:

http://technet.microsoft.com/en-us/library/dn464282.aspx

In V1 version of the patch I have addressed comments from
Olaf Hering <olaf@aepfle.de> and Dan Carpenter <dan.carpenter@oracle.com>

In V2 version of this patch I did some minor cleanup (making some globals
static). In V4 version of the patch I have addressed all of Olaf's
most recent set of comments/concerns.

In V5 version of the patch I had addressed Greg's most recent comments.
I would like to thank Greg for suggesting that I use misc device; it has
significantly simplified the code.

In V6 version of the patch I have cleaned up error message based on Olaf's
comments. I have also rebased the patch based on the current tip.

In this version of the patch, I have addressed the latest comments from Greg.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/uapi/linux/hyperv.h b/include/uapi/linux/hyperv.h
index 1861f8e..9beb7c9 100644
--- a/include/uapi/linux/hyperv.h
+++ b/include/uapi/linux/hyperv.h
@@ -25,6 +25,8 @@
 #ifndef _UAPI_HYPERV_H
 #define _UAPI_HYPERV_H
 
+#include <linux/uuid.h>
+
 /*
  * Framework version for util services.
  */
@@ -94,6 +96,50 @@ struct hv_vss_msg {
 } __attribute__((packed));
 
 /*
+ * Implementation of a host to guest copy facility.
+ */
+
+#define FCOPY_VERSION_0 0
+#define FCOPY_CURRENT_VERSION FCOPY_VERSION_0
+#define W_MAX_PATH 260
+
+enum hv_fcopy_op {
+	START_FILE_COPY = 0,
+	WRITE_TO_FILE,
+	COMPLETE_FCOPY,
+	CANCEL_FCOPY,
+};
+
+struct hv_fcopy_hdr {
+	__u32 operation;
+	uuid_le service_id0; /* currently unused */
+	uuid_le service_id1; /* currently unused */
+} __attribute__((packed));
+
+#define OVER_WRITE	0x1
+#define CREATE_PATH	0x2
+
+struct hv_start_fcopy {
+	struct hv_fcopy_hdr hdr;
+	__u16 file_name[W_MAX_PATH];
+	__u16 path_name[W_MAX_PATH];
+	__u32 copy_flags;
+	__u64 file_size;
+} __attribute__((packed));
+
+/*
+ * The file is chunked into fragments.
+ */
+#define DATA_FRAGMENT	(6 * 1024)
+
+struct hv_do_fcopy {
+	struct hv_fcopy_hdr hdr;
+	__u64	offset;
+	__u32	size;
+	__u8	data[DATA_FRAGMENT];
+};
+
+/*
  * An implementation of HyperV key value pair (KVP) functionality for Linux.
  *
  *