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1/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License version 2
4 * as published by the Free Software Foundation; or, when distributed
5 * separately from the Linux kernel or incorporated into other
6 * software packages, subject to the following license:
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this source file (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use, copy, modify,
11 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
12 * and to permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * IN THE SOFTWARE.
25 */
26
27#ifndef __XEN_BLKIF__BACKEND__COMMON_H__
28#define __XEN_BLKIF__BACKEND__COMMON_H__
29
30#include <linux/version.h>
31#include <linux/module.h>
32#include <linux/interrupt.h>
33#include <linux/slab.h>
34#include <linux/blkdev.h>
35#include <linux/vmalloc.h>
36#include <linux/wait.h>
37#include <linux/io.h>
38#include <asm/setup.h>
39#include <asm/pgalloc.h>
40#include <asm/hypervisor.h>
41#include <xen/grant_table.h>
42#include <xen/xenbus.h>
43#include <xen/interface/io/ring.h>
44#include <xen/interface/io/blkif.h>
45#include <xen/interface/io/protocols.h>
46
47#define DRV_PFX "xen-blkback:"
48#define DPRINTK(fmt, args...) \
49 pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
50 __func__, __LINE__, ##args)
51
52
53/* Not a real protocol. Used to generate ring structs which contain
54 * the elements common to all protocols only. This way we get a
55 * compiler-checkable way to use common struct elements, so we can
56 * avoid using switch(protocol) in a number of places. */
57struct blkif_common_request {
58 char dummy;
59};
60struct blkif_common_response {
61 char dummy;
62};
63
64/* i386 protocol version */
65#pragma pack(push, 4)
66struct blkif_x86_32_request {
67 uint8_t operation; /* BLKIF_OP_??? */
68 uint8_t nr_segments; /* number of segments */
69 blkif_vdev_t handle; /* only for read/write requests */
70 uint64_t id; /* private guest value, echoed in resp */
71 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
72 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
73};
74struct blkif_x86_32_response {
75 uint64_t id; /* copied from request */
76 uint8_t operation; /* copied from request */
77 int16_t status; /* BLKIF_RSP_??? */
78};
79#pragma pack(pop)
80
81/* x86_64 protocol version */
82struct blkif_x86_64_request {
83 uint8_t operation; /* BLKIF_OP_??? */
84 uint8_t nr_segments; /* number of segments */
85 blkif_vdev_t handle; /* only for read/write requests */
86 uint64_t __attribute__((__aligned__(8))) id;
87 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
88 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
89};
90struct blkif_x86_64_response {
91 uint64_t __attribute__((__aligned__(8))) id;
92 uint8_t operation; /* copied from request */
93 int16_t status; /* BLKIF_RSP_??? */
94};
95
96DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
97 struct blkif_common_response);
98DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
99 struct blkif_x86_32_response);
100DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
101 struct blkif_x86_64_response);
102
103union blkif_back_rings {
104 struct blkif_back_ring native;
105 struct blkif_common_back_ring common;
106 struct blkif_x86_32_back_ring x86_32;
107 struct blkif_x86_64_back_ring x86_64;
108};
109
110enum blkif_protocol {
111 BLKIF_PROTOCOL_NATIVE = 1,
112 BLKIF_PROTOCOL_X86_32 = 2,
113 BLKIF_PROTOCOL_X86_64 = 3,
114};
115
116struct xen_vbd {
117 /* What the domain refers to this vbd as. */
118 blkif_vdev_t handle;
119 /* Non-zero -> read-only */
120 unsigned char readonly;
121 /* VDISK_xxx */
122 unsigned char type;
123 /* phys device that this vbd maps to. */
124 u32 pdevice;
125 struct block_device *bdev;
126 /* Cached size parameter. */
127 sector_t size;
128 bool flush_support;
129};
130
131struct backend_info;
132
133struct xen_blkif {
134 /* Unique identifier for this interface. */
135 domid_t domid;
136 unsigned int handle;
137 /* Physical parameters of the comms window. */
138 unsigned int irq;
139 /* Comms information. */
140 enum blkif_protocol blk_protocol;
141 union blkif_back_rings blk_rings;
142 struct vm_struct *blk_ring_area;
143 /* The VBD attached to this interface. */
144 struct xen_vbd vbd;
145 /* Back pointer to the backend_info. */
146 struct backend_info *be;
147 /* Private fields. */
148 spinlock_t blk_ring_lock;
149 atomic_t refcnt;
150
151 wait_queue_head_t wq;
152 /* One thread per one blkif. */
153 struct task_struct *xenblkd;
154 unsigned int waiting_reqs;
155
156 /* statistics */
157 unsigned long st_print;
158 int st_rd_req;
159 int st_wr_req;
160 int st_oo_req;
161 int st_f_req;
162 int st_rd_sect;
163 int st_wr_sect;
164
165 wait_queue_head_t waiting_to_free;
166
167 grant_handle_t shmem_handle;
168 grant_ref_t shmem_ref;
169};
170
171
172#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
173 (_v)->bdev->bd_part->nr_sects : \
174 get_capacity((_v)->bdev->bd_disk))
175
176#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
177#define xen_blkif_put(_b) \
178 do { \
179 if (atomic_dec_and_test(&(_b)->refcnt)) \
180 wake_up(&(_b)->waiting_to_free);\
181 } while (0)
182
183struct phys_req {
184 unsigned short dev;
185 unsigned short nr_sects;
186 struct block_device *bdev;
187 blkif_sector_t sector_number;
188};
189int xen_blkif_interface_init(void);
190
191int xen_blkif_xenbus_init(void);
192
193irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
194int xen_blkif_schedule(void *arg);
195
196int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
197 struct backend_info *be, int state);
198
199struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
200
201static inline void blkif_get_x86_32_req(struct blkif_request *dst,
202 struct blkif_x86_32_request *src)
203{
204 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
205 dst->operation = src->operation;
206 dst->nr_segments = src->nr_segments;
207 dst->handle = src->handle;
208 dst->id = src->id;
209 dst->u.rw.sector_number = src->sector_number;
210 barrier();
211 if (n > dst->nr_segments)
212 n = dst->nr_segments;
213 for (i = 0; i < n; i++)
214 dst->u.rw.seg[i] = src->seg[i];
215}
216
217static inline void blkif_get_x86_64_req(struct blkif_request *dst,
218 struct blkif_x86_64_request *src)
219{
220 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
221 dst->operation = src->operation;
222 dst->nr_segments = src->nr_segments;
223 dst->handle = src->handle;
224 dst->id = src->id;
225 dst->u.rw.sector_number = src->sector_number;
226 barrier();
227 if (n > dst->nr_segments)
228 n = dst->nr_segments;
229 for (i = 0; i < n; i++)
230 dst->u.rw.seg[i] = src->seg[i];
231}
232
233#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */
1/*
2 * This program is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU General Public License version 2
4 * as published by the Free Software Foundation; or, when distributed
5 * separately from the Linux kernel or incorporated into other
6 * software packages, subject to the following license:
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a copy
9 * of this source file (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use, copy, modify,
11 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
12 * and to permit persons to whom the Software is furnished to do so, subject to
13 * the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included in
16 * all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
24 * IN THE SOFTWARE.
25 */
26
27#ifndef __XEN_BLKIF__BACKEND__COMMON_H__
28#define __XEN_BLKIF__BACKEND__COMMON_H__
29
30#include <linux/module.h>
31#include <linux/interrupt.h>
32#include <linux/slab.h>
33#include <linux/blkdev.h>
34#include <linux/vmalloc.h>
35#include <linux/wait.h>
36#include <linux/io.h>
37#include <linux/rbtree.h>
38#include <asm/setup.h>
39#include <asm/pgalloc.h>
40#include <asm/hypervisor.h>
41#include <xen/grant_table.h>
42#include <xen/xenbus.h>
43#include <xen/interface/io/ring.h>
44#include <xen/interface/io/blkif.h>
45#include <xen/interface/io/protocols.h>
46
47#define DRV_PFX "xen-blkback:"
48#define DPRINTK(fmt, args...) \
49 pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
50 __func__, __LINE__, ##args)
51
52
53/*
54 * This is the maximum number of segments that would be allowed in indirect
55 * requests. This value will also be passed to the frontend.
56 */
57#define MAX_INDIRECT_SEGMENTS 256
58
59#define SEGS_PER_INDIRECT_FRAME \
60 (PAGE_SIZE/sizeof(struct blkif_request_segment))
61#define MAX_INDIRECT_PAGES \
62 ((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
63#define INDIRECT_PAGES(_segs) \
64 ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME)
65
66/* Not a real protocol. Used to generate ring structs which contain
67 * the elements common to all protocols only. This way we get a
68 * compiler-checkable way to use common struct elements, so we can
69 * avoid using switch(protocol) in a number of places. */
70struct blkif_common_request {
71 char dummy;
72};
73struct blkif_common_response {
74 char dummy;
75};
76
77struct blkif_x86_32_request_rw {
78 uint8_t nr_segments; /* number of segments */
79 blkif_vdev_t handle; /* only for read/write requests */
80 uint64_t id; /* private guest value, echoed in resp */
81 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
82 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
83} __attribute__((__packed__));
84
85struct blkif_x86_32_request_discard {
86 uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
87 blkif_vdev_t _pad1; /* was "handle" for read/write requests */
88 uint64_t id; /* private guest value, echoed in resp */
89 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
90 uint64_t nr_sectors;
91} __attribute__((__packed__));
92
93struct blkif_x86_32_request_other {
94 uint8_t _pad1;
95 blkif_vdev_t _pad2;
96 uint64_t id; /* private guest value, echoed in resp */
97} __attribute__((__packed__));
98
99struct blkif_x86_32_request_indirect {
100 uint8_t indirect_op;
101 uint16_t nr_segments;
102 uint64_t id;
103 blkif_sector_t sector_number;
104 blkif_vdev_t handle;
105 uint16_t _pad1;
106 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
107 /*
108 * The maximum number of indirect segments (and pages) that will
109 * be used is determined by MAX_INDIRECT_SEGMENTS, this value
110 * is also exported to the guest (via xenstore
111 * feature-max-indirect-segments entry), so the frontend knows how
112 * many indirect segments the backend supports.
113 */
114 uint64_t _pad2; /* make it 64 byte aligned */
115} __attribute__((__packed__));
116
117struct blkif_x86_32_request {
118 uint8_t operation; /* BLKIF_OP_??? */
119 union {
120 struct blkif_x86_32_request_rw rw;
121 struct blkif_x86_32_request_discard discard;
122 struct blkif_x86_32_request_other other;
123 struct blkif_x86_32_request_indirect indirect;
124 } u;
125} __attribute__((__packed__));
126
127/* i386 protocol version */
128#pragma pack(push, 4)
129struct blkif_x86_32_response {
130 uint64_t id; /* copied from request */
131 uint8_t operation; /* copied from request */
132 int16_t status; /* BLKIF_RSP_??? */
133};
134#pragma pack(pop)
135/* x86_64 protocol version */
136
137struct blkif_x86_64_request_rw {
138 uint8_t nr_segments; /* number of segments */
139 blkif_vdev_t handle; /* only for read/write requests */
140 uint32_t _pad1; /* offsetof(blkif_reqest..,u.rw.id)==8 */
141 uint64_t id;
142 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
143 struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
144} __attribute__((__packed__));
145
146struct blkif_x86_64_request_discard {
147 uint8_t flag; /* BLKIF_DISCARD_SECURE or zero */
148 blkif_vdev_t _pad1; /* was "handle" for read/write requests */
149 uint32_t _pad2; /* offsetof(blkif_..,u.discard.id)==8 */
150 uint64_t id;
151 blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
152 uint64_t nr_sectors;
153} __attribute__((__packed__));
154
155struct blkif_x86_64_request_other {
156 uint8_t _pad1;
157 blkif_vdev_t _pad2;
158 uint32_t _pad3; /* offsetof(blkif_..,u.discard.id)==8 */
159 uint64_t id; /* private guest value, echoed in resp */
160} __attribute__((__packed__));
161
162struct blkif_x86_64_request_indirect {
163 uint8_t indirect_op;
164 uint16_t nr_segments;
165 uint32_t _pad1; /* offsetof(blkif_..,u.indirect.id)==8 */
166 uint64_t id;
167 blkif_sector_t sector_number;
168 blkif_vdev_t handle;
169 uint16_t _pad2;
170 grant_ref_t indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
171 /*
172 * The maximum number of indirect segments (and pages) that will
173 * be used is determined by MAX_INDIRECT_SEGMENTS, this value
174 * is also exported to the guest (via xenstore
175 * feature-max-indirect-segments entry), so the frontend knows how
176 * many indirect segments the backend supports.
177 */
178 uint32_t _pad3; /* make it 64 byte aligned */
179} __attribute__((__packed__));
180
181struct blkif_x86_64_request {
182 uint8_t operation; /* BLKIF_OP_??? */
183 union {
184 struct blkif_x86_64_request_rw rw;
185 struct blkif_x86_64_request_discard discard;
186 struct blkif_x86_64_request_other other;
187 struct blkif_x86_64_request_indirect indirect;
188 } u;
189} __attribute__((__packed__));
190
191struct blkif_x86_64_response {
192 uint64_t __attribute__((__aligned__(8))) id;
193 uint8_t operation; /* copied from request */
194 int16_t status; /* BLKIF_RSP_??? */
195};
196
197DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
198 struct blkif_common_response);
199DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
200 struct blkif_x86_32_response);
201DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
202 struct blkif_x86_64_response);
203
204union blkif_back_rings {
205 struct blkif_back_ring native;
206 struct blkif_common_back_ring common;
207 struct blkif_x86_32_back_ring x86_32;
208 struct blkif_x86_64_back_ring x86_64;
209};
210
211enum blkif_protocol {
212 BLKIF_PROTOCOL_NATIVE = 1,
213 BLKIF_PROTOCOL_X86_32 = 2,
214 BLKIF_PROTOCOL_X86_64 = 3,
215};
216
217struct xen_vbd {
218 /* What the domain refers to this vbd as. */
219 blkif_vdev_t handle;
220 /* Non-zero -> read-only */
221 unsigned char readonly;
222 /* VDISK_xxx */
223 unsigned char type;
224 /* phys device that this vbd maps to. */
225 u32 pdevice;
226 struct block_device *bdev;
227 /* Cached size parameter. */
228 sector_t size;
229 unsigned int flush_support:1;
230 unsigned int discard_secure:1;
231 unsigned int feature_gnt_persistent:1;
232 unsigned int overflow_max_grants:1;
233};
234
235struct backend_info;
236
237/* Number of available flags */
238#define PERSISTENT_GNT_FLAGS_SIZE 2
239/* This persistent grant is currently in use */
240#define PERSISTENT_GNT_ACTIVE 0
241/*
242 * This persistent grant has been used, this flag is set when we remove the
243 * PERSISTENT_GNT_ACTIVE, to know that this grant has been used recently.
244 */
245#define PERSISTENT_GNT_WAS_ACTIVE 1
246
247/* Number of requests that we can fit in a ring */
248#define XEN_BLKIF_REQS 32
249
250struct persistent_gnt {
251 struct page *page;
252 grant_ref_t gnt;
253 grant_handle_t handle;
254 DECLARE_BITMAP(flags, PERSISTENT_GNT_FLAGS_SIZE);
255 struct rb_node node;
256 struct list_head remove_node;
257};
258
259struct xen_blkif {
260 /* Unique identifier for this interface. */
261 domid_t domid;
262 unsigned int handle;
263 /* Physical parameters of the comms window. */
264 unsigned int irq;
265 /* Comms information. */
266 enum blkif_protocol blk_protocol;
267 union blkif_back_rings blk_rings;
268 void *blk_ring;
269 /* The VBD attached to this interface. */
270 struct xen_vbd vbd;
271 /* Back pointer to the backend_info. */
272 struct backend_info *be;
273 /* Private fields. */
274 spinlock_t blk_ring_lock;
275 atomic_t refcnt;
276
277 wait_queue_head_t wq;
278 /* for barrier (drain) requests */
279 struct completion drain_complete;
280 atomic_t drain;
281 atomic_t inflight;
282 /* One thread per one blkif. */
283 struct task_struct *xenblkd;
284 unsigned int waiting_reqs;
285
286 /* tree to store persistent grants */
287 struct rb_root persistent_gnts;
288 unsigned int persistent_gnt_c;
289 atomic_t persistent_gnt_in_use;
290 unsigned long next_lru;
291
292 /* used by the kworker that offload work from the persistent purge */
293 struct list_head persistent_purge_list;
294 struct work_struct persistent_purge_work;
295
296 /* buffer of free pages to map grant refs */
297 spinlock_t free_pages_lock;
298 int free_pages_num;
299 struct list_head free_pages;
300
301 /* List of all 'pending_req' available */
302 struct list_head pending_free;
303 /* And its spinlock. */
304 spinlock_t pending_free_lock;
305 wait_queue_head_t pending_free_wq;
306
307 /* statistics */
308 unsigned long st_print;
309 unsigned long long st_rd_req;
310 unsigned long long st_wr_req;
311 unsigned long long st_oo_req;
312 unsigned long long st_f_req;
313 unsigned long long st_ds_req;
314 unsigned long long st_rd_sect;
315 unsigned long long st_wr_sect;
316
317 wait_queue_head_t waiting_to_free;
318 /* Thread shutdown wait queue. */
319 wait_queue_head_t shutdown_wq;
320};
321
322struct seg_buf {
323 unsigned long offset;
324 unsigned int nsec;
325};
326
327struct grant_page {
328 struct page *page;
329 struct persistent_gnt *persistent_gnt;
330 grant_handle_t handle;
331 grant_ref_t gref;
332};
333
334/*
335 * Each outstanding request that we've passed to the lower device layers has a
336 * 'pending_req' allocated to it. Each buffer_head that completes decrements
337 * the pendcnt towards zero. When it hits zero, the specified domain has a
338 * response queued for it, with the saved 'id' passed back.
339 */
340struct pending_req {
341 struct xen_blkif *blkif;
342 u64 id;
343 int nr_pages;
344 atomic_t pendcnt;
345 unsigned short operation;
346 int status;
347 struct list_head free_list;
348 struct grant_page *segments[MAX_INDIRECT_SEGMENTS];
349 /* Indirect descriptors */
350 struct grant_page *indirect_pages[MAX_INDIRECT_PAGES];
351 struct seg_buf seg[MAX_INDIRECT_SEGMENTS];
352 struct bio *biolist[MAX_INDIRECT_SEGMENTS];
353};
354
355
356#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
357 (_v)->bdev->bd_part->nr_sects : \
358 get_capacity((_v)->bdev->bd_disk))
359
360#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
361#define xen_blkif_put(_b) \
362 do { \
363 if (atomic_dec_and_test(&(_b)->refcnt)) \
364 wake_up(&(_b)->waiting_to_free);\
365 } while (0)
366
367struct phys_req {
368 unsigned short dev;
369 blkif_sector_t nr_sects;
370 struct block_device *bdev;
371 blkif_sector_t sector_number;
372};
373int xen_blkif_interface_init(void);
374
375int xen_blkif_xenbus_init(void);
376
377irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
378int xen_blkif_schedule(void *arg);
379int xen_blkif_purge_persistent(void *arg);
380void xen_blkbk_free_caches(struct xen_blkif *blkif);
381
382int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
383 struct backend_info *be, int state);
384
385int xen_blkbk_barrier(struct xenbus_transaction xbt,
386 struct backend_info *be, int state);
387struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
388void xen_blkbk_unmap_purged_grants(struct work_struct *work);
389
390static inline void blkif_get_x86_32_req(struct blkif_request *dst,
391 struct blkif_x86_32_request *src)
392{
393 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
394 dst->operation = src->operation;
395 switch (src->operation) {
396 case BLKIF_OP_READ:
397 case BLKIF_OP_WRITE:
398 case BLKIF_OP_WRITE_BARRIER:
399 case BLKIF_OP_FLUSH_DISKCACHE:
400 dst->u.rw.nr_segments = src->u.rw.nr_segments;
401 dst->u.rw.handle = src->u.rw.handle;
402 dst->u.rw.id = src->u.rw.id;
403 dst->u.rw.sector_number = src->u.rw.sector_number;
404 barrier();
405 if (n > dst->u.rw.nr_segments)
406 n = dst->u.rw.nr_segments;
407 for (i = 0; i < n; i++)
408 dst->u.rw.seg[i] = src->u.rw.seg[i];
409 break;
410 case BLKIF_OP_DISCARD:
411 dst->u.discard.flag = src->u.discard.flag;
412 dst->u.discard.id = src->u.discard.id;
413 dst->u.discard.sector_number = src->u.discard.sector_number;
414 dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
415 break;
416 case BLKIF_OP_INDIRECT:
417 dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
418 dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
419 dst->u.indirect.handle = src->u.indirect.handle;
420 dst->u.indirect.id = src->u.indirect.id;
421 dst->u.indirect.sector_number = src->u.indirect.sector_number;
422 barrier();
423 j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
424 for (i = 0; i < j; i++)
425 dst->u.indirect.indirect_grefs[i] =
426 src->u.indirect.indirect_grefs[i];
427 break;
428 default:
429 /*
430 * Don't know how to translate this op. Only get the
431 * ID so failure can be reported to the frontend.
432 */
433 dst->u.other.id = src->u.other.id;
434 break;
435 }
436}
437
438static inline void blkif_get_x86_64_req(struct blkif_request *dst,
439 struct blkif_x86_64_request *src)
440{
441 int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j;
442 dst->operation = src->operation;
443 switch (src->operation) {
444 case BLKIF_OP_READ:
445 case BLKIF_OP_WRITE:
446 case BLKIF_OP_WRITE_BARRIER:
447 case BLKIF_OP_FLUSH_DISKCACHE:
448 dst->u.rw.nr_segments = src->u.rw.nr_segments;
449 dst->u.rw.handle = src->u.rw.handle;
450 dst->u.rw.id = src->u.rw.id;
451 dst->u.rw.sector_number = src->u.rw.sector_number;
452 barrier();
453 if (n > dst->u.rw.nr_segments)
454 n = dst->u.rw.nr_segments;
455 for (i = 0; i < n; i++)
456 dst->u.rw.seg[i] = src->u.rw.seg[i];
457 break;
458 case BLKIF_OP_DISCARD:
459 dst->u.discard.flag = src->u.discard.flag;
460 dst->u.discard.id = src->u.discard.id;
461 dst->u.discard.sector_number = src->u.discard.sector_number;
462 dst->u.discard.nr_sectors = src->u.discard.nr_sectors;
463 break;
464 case BLKIF_OP_INDIRECT:
465 dst->u.indirect.indirect_op = src->u.indirect.indirect_op;
466 dst->u.indirect.nr_segments = src->u.indirect.nr_segments;
467 dst->u.indirect.handle = src->u.indirect.handle;
468 dst->u.indirect.id = src->u.indirect.id;
469 dst->u.indirect.sector_number = src->u.indirect.sector_number;
470 barrier();
471 j = min(MAX_INDIRECT_PAGES, INDIRECT_PAGES(dst->u.indirect.nr_segments));
472 for (i = 0; i < j; i++)
473 dst->u.indirect.indirect_grefs[i] =
474 src->u.indirect.indirect_grefs[i];
475 break;
476 default:
477 /*
478 * Don't know how to translate this op. Only get the
479 * ID so failure can be reported to the frontend.
480 */
481 dst->u.other.id = src->u.other.id;
482 break;
483 }
484}
485
486#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */