win-pvdrivers

view common/include/public/grant_table.h @ 62:edd4a2ad5b44

Removed old inf files
author James Harper <james.harper@bendigoit.com.au>
date Wed Dec 19 10:22:50 2007 +1100 (2007-12-19)
parents 5712dede5a1b
children
line source
1 /******************************************************************************
2 * grant_table.h
3 *
4 * Interface for granting foreign access to page frames, and receiving
5 * page-ownership transfers.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to
9 * deal in the Software without restriction, including without limitation the
10 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
11 * sell copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
24 *
25 * Copyright (c) 2004, K A Fraser
26 */
28 #ifndef __XEN_PUBLIC_GRANT_TABLE_H__
29 #define __XEN_PUBLIC_GRANT_TABLE_H__
32 /***********************************
33 * GRANT TABLE REPRESENTATION
34 */
36 /* Some rough guidelines on accessing and updating grant-table entries
37 * in a concurrency-safe manner. For more information, Linux contains a
38 * reference implementation for guest OSes (arch/xen/kernel/grant_table.c).
39 *
40 * NB. WMB is a no-op on current-generation x86 processors. However, a
41 * compiler barrier will still be required.
42 *
43 * Introducing a valid entry into the grant table:
44 * 1. Write ent->domid.
45 * 2. Write ent->frame:
46 * GTF_permit_access: Frame to which access is permitted.
47 * GTF_accept_transfer: Pseudo-phys frame slot being filled by new
48 * frame, or zero if none.
49 * 3. Write memory barrier (WMB).
50 * 4. Write ent->flags, inc. valid type.
51 *
52 * Invalidating an unused GTF_permit_access entry:
53 * 1. flags = ent->flags.
54 * 2. Observe that !(flags & (GTF_reading|GTF_writing)).
55 * 3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0).
56 * NB. No need for WMB as reuse of entry is control-dependent on success of
57 * step 3, and all architectures guarantee ordering of ctrl-dep writes.
58 *
59 * Invalidating an in-use GTF_permit_access entry:
60 * This cannot be done directly. Request assistance from the domain controller
61 * which can set a timeout on the use of a grant entry and take necessary
62 * action. (NB. This is not yet implemented!).
63 *
64 * Invalidating an unused GTF_accept_transfer entry:
65 * 1. flags = ent->flags.
66 * 2. Observe that !(flags & GTF_transfer_committed). [*]
67 * 3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0).
68 * NB. No need for WMB as reuse of entry is control-dependent on success of
69 * step 3, and all architectures guarantee ordering of ctrl-dep writes.
70 * [*] If GTF_transfer_committed is set then the grant entry is 'committed'.
71 * The guest must /not/ modify the grant entry until the address of the
72 * transferred frame is written. It is safe for the guest to spin waiting
73 * for this to occur (detect by observing GTF_transfer_completed in
74 * ent->flags).
75 *
76 * Invalidating a committed GTF_accept_transfer entry:
77 * 1. Wait for (ent->flags & GTF_transfer_completed).
78 *
79 * Changing a GTF_permit_access from writable to read-only:
80 * Use SMP-safe CMPXCHG to set GTF_readonly, while checking !GTF_writing.
81 *
82 * Changing a GTF_permit_access from read-only to writable:
83 * Use SMP-safe bit-setting instruction.
84 */
86 /*
87 * A grant table comprises a packed array of grant entries in one or more
88 * page frames shared between Xen and a guest.
89 * [XEN]: This field is written by Xen and read by the sharing guest.
90 * [GST]: This field is written by the guest and read by Xen.
91 */
92 struct grant_entry {
93 /* GTF_xxx: various type and flag information. [XEN,GST] */
94 uint16_t flags;
95 /* The domain being granted foreign privileges. [GST] */
96 domid_t domid;
97 /*
98 * GTF_permit_access: Frame that @domid is allowed to map and access. [GST]
99 * GTF_accept_transfer: Frame whose ownership transferred by @domid. [XEN]
100 */
101 uint32_t frame;
102 };
103 typedef struct grant_entry grant_entry_t;
105 /*
106 * Type of grant entry.
107 * GTF_invalid: This grant entry grants no privileges.
108 * GTF_permit_access: Allow @domid to map/access @frame.
109 * GTF_accept_transfer: Allow @domid to transfer ownership of one page frame
110 * to this guest. Xen writes the page number to @frame.
111 */
112 #define GTF_invalid (0U<<0)
113 #define GTF_permit_access (1U<<0)
114 #define GTF_accept_transfer (2U<<0)
115 #define GTF_type_mask (3U<<0)
117 /*
118 * Subflags for GTF_permit_access.
119 * GTF_readonly: Restrict @domid to read-only mappings and accesses. [GST]
120 * GTF_reading: Grant entry is currently mapped for reading by @domid. [XEN]
121 * GTF_writing: Grant entry is currently mapped for writing by @domid. [XEN]
122 */
123 #define _GTF_readonly (2)
124 #define GTF_readonly (1U<<_GTF_readonly)
125 #define _GTF_reading (3)
126 #define GTF_reading (1U<<_GTF_reading)
127 #define _GTF_writing (4)
128 #define GTF_writing (1U<<_GTF_writing)
130 /*
131 * Subflags for GTF_accept_transfer:
132 * GTF_transfer_committed: Xen sets this flag to indicate that it is committed
133 * to transferring ownership of a page frame. When a guest sees this flag
134 * it must /not/ modify the grant entry until GTF_transfer_completed is
135 * set by Xen.
136 * GTF_transfer_completed: It is safe for the guest to spin-wait on this flag
137 * after reading GTF_transfer_committed. Xen will always write the frame
138 * address, followed by ORing this flag, in a timely manner.
139 */
140 #define _GTF_transfer_committed (2)
141 #define GTF_transfer_committed (1U<<_GTF_transfer_committed)
142 #define _GTF_transfer_completed (3)
143 #define GTF_transfer_completed (1U<<_GTF_transfer_completed)
146 /***********************************
147 * GRANT TABLE QUERIES AND USES
148 */
150 /*
151 * Reference to a grant entry in a specified domain's grant table.
152 */
153 typedef uint32_t grant_ref_t;
155 /*
156 * Handle to track a mapping created via a grant reference.
157 */
158 typedef uint32_t grant_handle_t;
160 /*
161 * GNTTABOP_map_grant_ref: Map the grant entry (<dom>,<ref>) for access
162 * by devices and/or host CPUs. If successful, <handle> is a tracking number
163 * that must be presented later to destroy the mapping(s). On error, <handle>
164 * is a negative status code.
165 * NOTES:
166 * 1. If GNTMAP_device_map is specified then <dev_bus_addr> is the address
167 * via which I/O devices may access the granted frame.
168 * 2. If GNTMAP_host_map is specified then a mapping will be added at
169 * either a host virtual address in the current address space, or at
170 * a PTE at the specified machine address. The type of mapping to
171 * perform is selected through the GNTMAP_contains_pte flag, and the
172 * address is specified in <host_addr>.
173 * 3. Mappings should only be destroyed via GNTTABOP_unmap_grant_ref. If a
174 * host mapping is destroyed by other means then it is *NOT* guaranteed
175 * to be accounted to the correct grant reference!
176 */
177 #define GNTTABOP_map_grant_ref 0
178 struct gnttab_map_grant_ref {
179 /* IN parameters. */
180 uint64_t host_addr;
181 uint32_t flags; /* GNTMAP_* */
182 grant_ref_t ref;
183 domid_t dom;
184 /* OUT parameters. */
185 int16_t status; /* GNTST_* */
186 grant_handle_t handle;
187 uint64_t dev_bus_addr;
188 };
189 typedef struct gnttab_map_grant_ref gnttab_map_grant_ref_t;
190 DEFINE_XEN_GUEST_HANDLE(gnttab_map_grant_ref_t);
192 /*
193 * GNTTABOP_unmap_grant_ref: Destroy one or more grant-reference mappings
194 * tracked by <handle>. If <host_addr> or <dev_bus_addr> is zero, that
195 * field is ignored. If non-zero, they must refer to a device/host mapping
196 * that is tracked by <handle>
197 * NOTES:
198 * 1. The call may fail in an undefined manner if either mapping is not
199 * tracked by <handle>.
200 * 3. After executing a batch of unmaps, it is guaranteed that no stale
201 * mappings will remain in the device or host TLBs.
202 */
203 #define GNTTABOP_unmap_grant_ref 1
204 struct gnttab_unmap_grant_ref {
205 /* IN parameters. */
206 uint64_t host_addr;
207 uint64_t dev_bus_addr;
208 grant_handle_t handle;
209 /* OUT parameters. */
210 int16_t status; /* GNTST_* */
211 };
212 typedef struct gnttab_unmap_grant_ref gnttab_unmap_grant_ref_t;
213 DEFINE_XEN_GUEST_HANDLE(gnttab_unmap_grant_ref_t);
215 /*
216 * GNTTABOP_setup_table: Set up a grant table for <dom> comprising at least
217 * <nr_frames> pages. The frame addresses are written to the <frame_list>.
218 * Only <nr_frames> addresses are written, even if the table is larger.
219 * NOTES:
220 * 1. <dom> may be specified as DOMID_SELF.
221 * 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
222 * 3. Xen may not support more than a single grant-table page per domain.
223 */
224 #define GNTTABOP_setup_table 2
225 struct gnttab_setup_table {
226 /* IN parameters. */
227 domid_t dom;
228 uint32_t nr_frames;
229 /* OUT parameters. */
230 int16_t status; /* GNTST_* */
231 XEN_GUEST_HANDLE(ulong) frame_list;
232 };
233 typedef struct gnttab_setup_table gnttab_setup_table_t;
234 DEFINE_XEN_GUEST_HANDLE(gnttab_setup_table_t);
236 /*
237 * GNTTABOP_dump_table: Dump the contents of the grant table to the
238 * xen console. Debugging use only.
239 */
240 #define GNTTABOP_dump_table 3
241 struct gnttab_dump_table {
242 /* IN parameters. */
243 domid_t dom;
244 /* OUT parameters. */
245 int16_t status; /* GNTST_* */
246 };
247 typedef struct gnttab_dump_table gnttab_dump_table_t;
248 DEFINE_XEN_GUEST_HANDLE(gnttab_dump_table_t);
250 /*
251 * GNTTABOP_transfer_grant_ref: Transfer <frame> to a foreign domain. The
252 * foreign domain has previously registered its interest in the transfer via
253 * <domid, ref>.
254 *
255 * Note that, even if the transfer fails, the specified page no longer belongs
256 * to the calling domain *unless* the error is GNTST_bad_page.
257 */
258 #define GNTTABOP_transfer 4
259 struct gnttab_transfer {
260 /* IN parameters. */
261 xen_pfn_t mfn;
262 domid_t domid;
263 grant_ref_t ref;
264 /* OUT parameters. */
265 int16_t status;
266 };
267 typedef struct gnttab_transfer gnttab_transfer_t;
268 DEFINE_XEN_GUEST_HANDLE(gnttab_transfer_t);
271 /*
272 * GNTTABOP_copy: Hypervisor based copy
273 * source and destinations can be eithers MFNs or, for foreign domains,
274 * grant references. the foreign domain has to grant read/write access
275 * in its grant table.
276 *
277 * The flags specify what type source and destinations are (either MFN
278 * or grant reference).
279 *
280 * Note that this can also be used to copy data between two domains
281 * via a third party if the source and destination domains had previously
282 * grant appropriate access to their pages to the third party.
283 *
284 * source_offset specifies an offset in the source frame, dest_offset
285 * the offset in the target frame and len specifies the number of
286 * bytes to be copied.
287 */
289 #define _GNTCOPY_source_gref (0)
290 #define GNTCOPY_source_gref (1<<_GNTCOPY_source_gref)
291 #define _GNTCOPY_dest_gref (1)
292 #define GNTCOPY_dest_gref (1<<_GNTCOPY_dest_gref)
294 #define GNTTABOP_copy 5
295 typedef struct gnttab_copy {
296 /* IN parameters. */
297 struct {
298 union {
299 grant_ref_t ref;
300 xen_pfn_t gmfn;
301 } u;
302 domid_t domid;
303 uint16_t offset;
304 } source, dest;
305 uint16_t len;
306 uint16_t flags; /* GNTCOPY_* */
307 /* OUT parameters. */
308 int16_t status;
309 } gnttab_copy_t;
310 DEFINE_XEN_GUEST_HANDLE(gnttab_copy_t);
312 /*
313 * GNTTABOP_query_size: Query the current and maximum sizes of the shared
314 * grant table.
315 * NOTES:
316 * 1. <dom> may be specified as DOMID_SELF.
317 * 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
318 */
319 #define GNTTABOP_query_size 6
320 struct gnttab_query_size {
321 /* IN parameters. */
322 domid_t dom;
323 /* OUT parameters. */
324 uint32_t nr_frames;
325 uint32_t max_nr_frames;
326 int16_t status; /* GNTST_* */
327 };
328 typedef struct gnttab_query_size gnttab_query_size_t;
329 DEFINE_XEN_GUEST_HANDLE(gnttab_query_size_t);
332 /*
333 * Bitfield values for update_pin_status.flags.
334 */
335 /* Map the grant entry for access by I/O devices. */
336 #define _GNTMAP_device_map (0)
337 #define GNTMAP_device_map (1<<_GNTMAP_device_map)
338 /* Map the grant entry for access by host CPUs. */
339 #define _GNTMAP_host_map (1)
340 #define GNTMAP_host_map (1<<_GNTMAP_host_map)
341 /* Accesses to the granted frame will be restricted to read-only access. */
342 #define _GNTMAP_readonly (2)
343 #define GNTMAP_readonly (1<<_GNTMAP_readonly)
344 /*
345 * GNTMAP_host_map subflag:
346 * 0 => The host mapping is usable only by the guest OS.
347 * 1 => The host mapping is usable by guest OS + current application.
348 */
349 #define _GNTMAP_application_map (3)
350 #define GNTMAP_application_map (1<<_GNTMAP_application_map)
352 /*
353 * GNTMAP_contains_pte subflag:
354 * 0 => This map request contains a host virtual address.
355 * 1 => This map request contains the machine addess of the PTE to update.
356 */
357 #define _GNTMAP_contains_pte (4)
358 #define GNTMAP_contains_pte (1<<_GNTMAP_contains_pte)
360 /*
361 * Values for error status returns. All errors are -ve.
362 */
363 #define GNTST_okay (0) /* Normal return. */
364 #define GNTST_general_error (-1) /* General undefined error. */
365 #define GNTST_bad_domain (-2) /* Unrecognsed domain id. */
366 #define GNTST_bad_gntref (-3) /* Unrecognised or inappropriate gntref. */
367 #define GNTST_bad_handle (-4) /* Unrecognised or inappropriate handle. */
368 #define GNTST_bad_virt_addr (-5) /* Inappropriate virtual address to map. */
369 #define GNTST_bad_dev_addr (-6) /* Inappropriate device address to unmap.*/
370 #define GNTST_no_device_space (-7) /* Out of space in I/O MMU. */
371 #define GNTST_permission_denied (-8) /* Not enough privilege for operation. */
372 #define GNTST_bad_page (-9) /* Specified page was invalid for op. */
373 #define GNTST_bad_copy_arg (-10) /* copy arguments cross page boundary */
375 #define GNTTABOP_error_msgs { \
376 "okay", \
377 "undefined error", \
378 "unrecognised domain id", \
379 "invalid grant reference", \
380 "invalid mapping handle", \
381 "invalid virtual address", \
382 "invalid device address", \
383 "no spare translation slot in the I/O MMU", \
384 "permission denied", \
385 "bad page", \
386 "copy arguments cross page boundary" \
387 }
389 #endif /* __XEN_PUBLIC_GRANT_TABLE_H__ */
391 /*
392 * Local variables:
393 * mode: C
394 * c-set-style: "BSD"
395 * c-basic-offset: 4
396 * tab-width: 4
397 * indent-tabs-mode: nil
398 * End:
399 */