]>
git.ipfire.org Git - people/ms/linux.git/blob - drivers/hv/hv_fcopy.c
1 // SPDX-License-Identifier: GPL-2.0-only
3 * An implementation of file copy service.
5 * Copyright (C) 2014, Microsoft, Inc.
7 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/nls.h>
13 #include <linux/workqueue.h>
14 #include <linux/hyperv.h>
15 #include <linux/sched.h>
16 #include <asm/hyperv-tlfs.h>
18 #include "hyperv_vmbus.h"
19 #include "hv_utils_transport.h"
21 #define WIN8_SRV_MAJOR 1
22 #define WIN8_SRV_MINOR 1
23 #define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
25 #define FCOPY_VER_COUNT 1
26 static const int fcopy_versions
[] = {
30 #define FW_VER_COUNT 1
31 static const int fw_versions
[] = {
36 * Global state maintained for transaction that is being processed.
37 * For a class of integration services, including the "file copy service",
38 * the specified protocol is a "request/response" protocol which means that
39 * there can only be single outstanding transaction from the host at any
40 * given point in time. We use this to simplify memory management in this
41 * driver - we cache and process only one message at a time.
43 * While the request/response protocol is guaranteed by the host, we further
44 * ensure this by serializing packet processing in this driver - we do not
45 * read additional packets from the VMBUs until the current packet is fully
50 int state
; /* hvutil_device_state */
51 int recv_len
; /* number of bytes received. */
52 struct hv_fcopy_hdr
*fcopy_msg
; /* current message */
53 struct vmbus_channel
*recv_channel
; /* chn we got the request */
54 u64 recv_req_id
; /* request ID. */
57 static void fcopy_respond_to_host(int error
);
58 static void fcopy_send_data(struct work_struct
*dummy
);
59 static void fcopy_timeout_func(struct work_struct
*dummy
);
60 static DECLARE_DELAYED_WORK(fcopy_timeout_work
, fcopy_timeout_func
);
61 static DECLARE_WORK(fcopy_send_work
, fcopy_send_data
);
62 static const char fcopy_devname
[] = "vmbus/hv_fcopy";
63 static u8
*recv_buffer
;
64 static struct hvutil_transport
*hvt
;
66 * This state maintains the version number registered by the daemon.
68 static int dm_reg_value
;
70 static void fcopy_poll_wrapper(void *channel
)
72 /* Transaction is finished, reset the state here to avoid races. */
73 fcopy_transaction
.state
= HVUTIL_READY
;
74 tasklet_schedule(&((struct vmbus_channel
*)channel
)->callback_event
);
77 static void fcopy_timeout_func(struct work_struct
*dummy
)
80 * If the timer fires, the user-mode component has not responded;
81 * process the pending transaction.
83 fcopy_respond_to_host(HV_E_FAIL
);
84 hv_poll_channel(fcopy_transaction
.recv_channel
, fcopy_poll_wrapper
);
87 static void fcopy_register_done(void)
89 pr_debug("FCP: userspace daemon registered\n");
90 hv_poll_channel(fcopy_transaction
.recv_channel
, fcopy_poll_wrapper
);
93 static int fcopy_handle_handshake(u32 version
)
95 u32 our_ver
= FCOPY_CURRENT_VERSION
;
99 /* Daemon doesn't expect us to reply */
100 dm_reg_value
= version
;
102 case FCOPY_VERSION_1
:
103 /* Daemon expects us to reply with our own version */
104 if (hvutil_transport_send(hvt
, &our_ver
, sizeof(our_ver
),
105 fcopy_register_done
))
107 dm_reg_value
= version
;
111 * For now we will fail the registration.
112 * If and when we have multiple versions to
113 * deal with, we will be backward compatible.
114 * We will add this code when needed.
118 pr_debug("FCP: userspace daemon ver. %d connected\n", version
);
122 static void fcopy_send_data(struct work_struct
*dummy
)
124 struct hv_start_fcopy
*smsg_out
= NULL
;
125 int operation
= fcopy_transaction
.fcopy_msg
->operation
;
126 struct hv_start_fcopy
*smsg_in
;
131 * The strings sent from the host are encoded in
132 * in utf16; convert it to utf8 strings.
133 * The host assures us that the utf16 strings will not exceed
134 * the max lengths specified. We will however, reserve room
135 * for the string terminating character - in the utf16s_utf8s()
136 * function we limit the size of the buffer where the converted
137 * string is placed to W_MAX_PATH -1 to guarantee
138 * that the strings can be properly terminated!
142 case START_FILE_COPY
:
143 out_len
= sizeof(struct hv_start_fcopy
);
144 smsg_out
= kzalloc(sizeof(*smsg_out
), GFP_KERNEL
);
148 smsg_out
->hdr
.operation
= operation
;
149 smsg_in
= (struct hv_start_fcopy
*)fcopy_transaction
.fcopy_msg
;
151 utf16s_to_utf8s((wchar_t *)smsg_in
->file_name
, W_MAX_PATH
,
153 (__u8
*)&smsg_out
->file_name
, W_MAX_PATH
- 1);
155 utf16s_to_utf8s((wchar_t *)smsg_in
->path_name
, W_MAX_PATH
,
157 (__u8
*)&smsg_out
->path_name
, W_MAX_PATH
- 1);
159 smsg_out
->copy_flags
= smsg_in
->copy_flags
;
160 smsg_out
->file_size
= smsg_in
->file_size
;
165 out_src
= fcopy_transaction
.fcopy_msg
;
166 out_len
= sizeof(struct hv_do_fcopy
);
169 out_src
= fcopy_transaction
.fcopy_msg
;
170 out_len
= fcopy_transaction
.recv_len
;
174 fcopy_transaction
.state
= HVUTIL_USERSPACE_REQ
;
175 rc
= hvutil_transport_send(hvt
, out_src
, out_len
, NULL
);
177 pr_debug("FCP: failed to communicate to the daemon: %d\n", rc
);
178 if (cancel_delayed_work_sync(&fcopy_timeout_work
)) {
179 fcopy_respond_to_host(HV_E_FAIL
);
180 fcopy_transaction
.state
= HVUTIL_READY
;
187 * Send a response back to the host.
191 fcopy_respond_to_host(int error
)
193 struct icmsg_hdr
*icmsghdr
;
195 struct vmbus_channel
*channel
;
199 * Copy the global state for completing the transaction. Note that
200 * only one transaction can be active at a time. This is guaranteed
201 * by the file copy protocol implemented by the host. Furthermore,
202 * the "transaction active" state we maintain ensures that there can
203 * only be one active transaction at a time.
206 buf_len
= fcopy_transaction
.recv_len
;
207 channel
= fcopy_transaction
.recv_channel
;
208 req_id
= fcopy_transaction
.recv_req_id
;
210 icmsghdr
= (struct icmsg_hdr
*)
211 &recv_buffer
[sizeof(struct vmbuspipe_hdr
)];
213 if (channel
->onchannel_callback
== NULL
)
215 * We have raced with util driver being unloaded;
220 icmsghdr
->status
= error
;
221 icmsghdr
->icflags
= ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE
;
222 vmbus_sendpacket(channel
, recv_buffer
, buf_len
, req_id
,
223 VM_PKT_DATA_INBAND
, 0);
226 void hv_fcopy_onchannelcallback(void *context
)
228 struct vmbus_channel
*channel
= context
;
231 struct hv_fcopy_hdr
*fcopy_msg
;
232 struct icmsg_hdr
*icmsghdr
;
233 int fcopy_srv_version
;
235 if (fcopy_transaction
.state
> HVUTIL_READY
)
238 if (vmbus_recvpacket(channel
, recv_buffer
, HV_HYP_PAGE_SIZE
* 2, &recvlen
, &requestid
)) {
239 pr_err_ratelimited("Fcopy request received. Could not read into recv buf\n");
246 /* Ensure recvlen is big enough to read header data */
247 if (recvlen
< ICMSG_HDR
) {
248 pr_err_ratelimited("Fcopy request received. Packet length too small: %d\n",
253 icmsghdr
= (struct icmsg_hdr
*)&recv_buffer
[
254 sizeof(struct vmbuspipe_hdr
)];
256 if (icmsghdr
->icmsgtype
== ICMSGTYPE_NEGOTIATE
) {
257 if (vmbus_prep_negotiate_resp(icmsghdr
,
258 recv_buffer
, recvlen
,
259 fw_versions
, FW_VER_COUNT
,
260 fcopy_versions
, FCOPY_VER_COUNT
,
261 NULL
, &fcopy_srv_version
)) {
263 pr_info("FCopy IC version %d.%d\n",
264 fcopy_srv_version
>> 16,
265 fcopy_srv_version
& 0xFFFF);
267 } else if (icmsghdr
->icmsgtype
== ICMSGTYPE_FCOPY
) {
268 /* Ensure recvlen is big enough to contain hv_fcopy_hdr */
269 if (recvlen
< ICMSG_HDR
+ sizeof(struct hv_fcopy_hdr
)) {
270 pr_err_ratelimited("Invalid Fcopy hdr. Packet length too small: %u\n",
274 fcopy_msg
= (struct hv_fcopy_hdr
*)&recv_buffer
[ICMSG_HDR
];
277 * Stash away this global state for completing the
278 * transaction; note transactions are serialized.
281 fcopy_transaction
.recv_len
= recvlen
;
282 fcopy_transaction
.recv_req_id
= requestid
;
283 fcopy_transaction
.fcopy_msg
= fcopy_msg
;
285 if (fcopy_transaction
.state
< HVUTIL_READY
) {
286 /* Userspace is not registered yet */
287 fcopy_respond_to_host(HV_E_FAIL
);
290 fcopy_transaction
.state
= HVUTIL_HOSTMSG_RECEIVED
;
293 * Send the information to the user-level daemon.
295 schedule_work(&fcopy_send_work
);
296 schedule_delayed_work(&fcopy_timeout_work
,
297 HV_UTIL_TIMEOUT
* HZ
);
300 pr_err_ratelimited("Fcopy request received. Invalid msg type: %d\n",
301 icmsghdr
->icmsgtype
);
304 icmsghdr
->icflags
= ICMSGHDRFLAG_TRANSACTION
| ICMSGHDRFLAG_RESPONSE
;
305 vmbus_sendpacket(channel
, recv_buffer
, recvlen
, requestid
,
306 VM_PKT_DATA_INBAND
, 0);
309 /* Callback when data is received from userspace */
310 static int fcopy_on_msg(void *msg
, int len
)
312 int *val
= (int *)msg
;
314 if (len
!= sizeof(int))
317 if (fcopy_transaction
.state
== HVUTIL_DEVICE_INIT
)
318 return fcopy_handle_handshake(*val
);
320 if (fcopy_transaction
.state
!= HVUTIL_USERSPACE_REQ
)
324 * Complete the transaction by forwarding the result
325 * to the host. But first, cancel the timeout.
327 if (cancel_delayed_work_sync(&fcopy_timeout_work
)) {
328 fcopy_transaction
.state
= HVUTIL_USERSPACE_RECV
;
329 fcopy_respond_to_host(*val
);
330 hv_poll_channel(fcopy_transaction
.recv_channel
,
337 static void fcopy_on_reset(void)
340 * The daemon has exited; reset the state.
342 fcopy_transaction
.state
= HVUTIL_DEVICE_INIT
;
344 if (cancel_delayed_work_sync(&fcopy_timeout_work
))
345 fcopy_respond_to_host(HV_E_FAIL
);
348 int hv_fcopy_init(struct hv_util_service
*srv
)
350 recv_buffer
= srv
->recv_buffer
;
351 fcopy_transaction
.recv_channel
= srv
->channel
;
352 fcopy_transaction
.recv_channel
->max_pkt_size
= HV_HYP_PAGE_SIZE
* 2;
355 * When this driver loads, the user level daemon that
356 * processes the host requests may not yet be running.
357 * Defer processing channel callbacks until the daemon
360 fcopy_transaction
.state
= HVUTIL_DEVICE_INIT
;
362 hvt
= hvutil_transport_init(fcopy_devname
, 0, 0,
363 fcopy_on_msg
, fcopy_on_reset
);
370 static void hv_fcopy_cancel_work(void)
372 cancel_delayed_work_sync(&fcopy_timeout_work
);
373 cancel_work_sync(&fcopy_send_work
);
376 int hv_fcopy_pre_suspend(void)
378 struct vmbus_channel
*channel
= fcopy_transaction
.recv_channel
;
379 struct hv_fcopy_hdr
*fcopy_msg
;
382 * Fake a CANCEL_FCOPY message for the user space daemon in case the
383 * daemon is in the middle of copying some file. It doesn't matter if
384 * there is already a message pending to be delivered to the user
385 * space since we force fcopy_transaction.state to be HVUTIL_READY, so
386 * the user space daemon's write() will fail with EINVAL (see
387 * fcopy_on_msg()), and the daemon will reset the device by closing
390 fcopy_msg
= kzalloc(sizeof(*fcopy_msg
), GFP_KERNEL
);
394 tasklet_disable(&channel
->callback_event
);
396 fcopy_msg
->operation
= CANCEL_FCOPY
;
398 hv_fcopy_cancel_work();
400 /* We don't care about the return value. */
401 hvutil_transport_send(hvt
, fcopy_msg
, sizeof(*fcopy_msg
), NULL
);
405 fcopy_transaction
.state
= HVUTIL_READY
;
407 /* tasklet_enable() will be called in hv_fcopy_pre_resume(). */
411 int hv_fcopy_pre_resume(void)
413 struct vmbus_channel
*channel
= fcopy_transaction
.recv_channel
;
415 tasklet_enable(&channel
->callback_event
);
420 void hv_fcopy_deinit(void)
422 fcopy_transaction
.state
= HVUTIL_DEVICE_DYING
;
424 hv_fcopy_cancel_work();
426 hvutil_transport_destroy(hvt
);