]>
Commit | Line | Data |
---|---|---|
1 | /** @file\r | |
2 | Grant Table function implementation.\r | |
3 | \r | |
4 | Grant Table are used to grant access to certain page of the current\r | |
5 | VM to an other VM.\r | |
6 | \r | |
7 | Author: Steven Smith (sos22@cam.ac.uk)\r | |
8 | Changes: Grzegorz Milos (gm281@cam.ac.uk)\r | |
9 | Copyright (C) 2006, Cambridge University\r | |
10 | Copyright (C) 2014, Citrix Ltd.\r | |
11 | \r | |
12 | Redistribution and use in source and binary forms, with or without\r | |
13 | modification, are permitted provided that the following conditions\r | |
14 | are met:\r | |
15 | 1. Redistributions of source code must retain the above copyright\r | |
16 | notice, this list of conditions and the following disclaimer.\r | |
17 | 2. Redistributions in binary form must reproduce the above copyright\r | |
18 | notice, this list of conditions and the following disclaimer in the\r | |
19 | documentation and/or other materials provided with the distribution.\r | |
20 | \r | |
21 | THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND\r | |
22 | ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE\r | |
23 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE\r | |
24 | ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE\r | |
25 | FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL\r | |
26 | DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS\r | |
27 | OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)\r | |
28 | HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT\r | |
29 | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY\r | |
30 | OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF\r | |
31 | SUCH DAMAGE.\r | |
32 | **/\r | |
33 | #include "XenBusDxe.h"\r | |
34 | \r | |
35 | #include <IndustryStandard/Xen/memory.h>\r | |
36 | \r | |
37 | #include <Library/XenHypercallLib.h>\r | |
38 | #include <Library/SynchronizationLib.h>\r | |
39 | \r | |
40 | #include "GrantTable.h"\r | |
41 | \r | |
42 | #define NR_RESERVED_ENTRIES 8\r | |
43 | \r | |
44 | /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */\r | |
45 | #define NR_GRANT_FRAMES 4\r | |
46 | #define NR_GRANT_ENTRIES (NR_GRANT_FRAMES * EFI_PAGE_SIZE / sizeof(grant_entry_v1_t))\r | |
47 | \r | |
48 | STATIC grant_entry_v1_t *GrantTable = NULL;\r | |
49 | STATIC grant_ref_t GrantList[NR_GRANT_ENTRIES];\r | |
50 | STATIC EFI_LOCK mGrantListLock;\r | |
51 | #ifdef GNT_DEBUG\r | |
52 | STATIC BOOLEAN GrantInUseList[NR_GRANT_ENTRIES];\r | |
53 | #endif\r | |
54 | \r | |
55 | STATIC\r | |
56 | VOID\r | |
57 | XenGrantTablePutFreeEntry (\r | |
58 | grant_ref_t Ref\r | |
59 | )\r | |
60 | {\r | |
61 | EfiAcquireLock (&mGrantListLock);\r | |
62 | #ifdef GNT_DEBUG\r | |
63 | ASSERT (GrantInUseList[Ref]);\r | |
64 | GrantInUseList[Ref] = FALSE;\r | |
65 | #endif\r | |
66 | GrantList[Ref] = GrantList[0];\r | |
67 | GrantList[0] = Ref;\r | |
68 | EfiReleaseLock (&mGrantListLock);\r | |
69 | }\r | |
70 | \r | |
71 | STATIC\r | |
72 | grant_ref_t\r | |
73 | XenGrantTableGetFreeEntry (\r | |
74 | VOID\r | |
75 | )\r | |
76 | {\r | |
77 | grant_ref_t Ref;\r | |
78 | \r | |
79 | EfiAcquireLock (&mGrantListLock);\r | |
80 | Ref = GrantList[0];\r | |
81 | ASSERT (Ref >= NR_RESERVED_ENTRIES && Ref < NR_GRANT_ENTRIES);\r | |
82 | GrantList[0] = GrantList[Ref];\r | |
83 | #ifdef GNT_DEBUG\r | |
84 | ASSERT (!GrantInUseList[Ref]);\r | |
85 | GrantInUseList[Ref] = TRUE;\r | |
86 | #endif\r | |
87 | EfiReleaseLock (&mGrantListLock);\r | |
88 | return Ref;\r | |
89 | }\r | |
90 | \r | |
91 | STATIC\r | |
92 | grant_ref_t\r | |
93 | XenGrantTableGrantAccess (\r | |
94 | IN domid_t DomainId,\r | |
95 | IN UINTN Frame,\r | |
96 | IN BOOLEAN ReadOnly\r | |
97 | )\r | |
98 | {\r | |
99 | grant_ref_t Ref;\r | |
100 | UINT16 Flags;\r | |
101 | \r | |
102 | ASSERT (GrantTable != NULL);\r | |
103 | Ref = XenGrantTableGetFreeEntry ();\r | |
104 | GrantTable[Ref].frame = (UINT32)Frame;\r | |
105 | GrantTable[Ref].domid = DomainId;\r | |
106 | MemoryFence ();\r | |
107 | Flags = GTF_permit_access;\r | |
108 | if (ReadOnly) {\r | |
109 | Flags |= GTF_readonly;\r | |
110 | }\r | |
111 | GrantTable[Ref].flags = Flags;\r | |
112 | \r | |
113 | return Ref;\r | |
114 | }\r | |
115 | \r | |
116 | STATIC\r | |
117 | EFI_STATUS\r | |
118 | XenGrantTableEndAccess (\r | |
119 | grant_ref_t Ref\r | |
120 | )\r | |
121 | {\r | |
122 | UINT16 Flags, OldFlags;\r | |
123 | \r | |
124 | ASSERT (GrantTable != NULL);\r | |
125 | ASSERT (Ref >= NR_RESERVED_ENTRIES && Ref < NR_GRANT_ENTRIES);\r | |
126 | \r | |
127 | OldFlags = GrantTable[Ref].flags;\r | |
128 | do {\r | |
129 | if ((Flags = OldFlags) & (GTF_reading | GTF_writing)) {\r | |
130 | DEBUG ((EFI_D_WARN, "WARNING: g.e. still in use! (%x)\n", Flags));\r | |
131 | return EFI_NOT_READY;\r | |
132 | }\r | |
133 | OldFlags = InterlockedCompareExchange16 (&GrantTable[Ref].flags, Flags, 0);\r | |
134 | } while (OldFlags != Flags);\r | |
135 | \r | |
136 | XenGrantTablePutFreeEntry (Ref);\r | |
137 | return EFI_SUCCESS;\r | |
138 | }\r | |
139 | \r | |
140 | VOID\r | |
141 | XenGrantTableInit (\r | |
142 | IN XENBUS_DEVICE *Dev\r | |
143 | )\r | |
144 | {\r | |
145 | xen_add_to_physmap_t Parameters;\r | |
146 | INTN Index;\r | |
147 | INTN ReturnCode;\r | |
148 | \r | |
149 | #ifdef GNT_DEBUG\r | |
150 | SetMem(GrantInUseList, sizeof (GrantInUseList), 1);\r | |
151 | #endif\r | |
152 | EfiInitializeLock (&mGrantListLock, TPL_NOTIFY);\r | |
153 | for (Index = NR_RESERVED_ENTRIES; Index < NR_GRANT_ENTRIES; Index++) {\r | |
154 | XenGrantTablePutFreeEntry ((grant_ref_t)Index);\r | |
155 | }\r | |
156 | \r | |
157 | GrantTable = (VOID*)(UINTN) Dev->XenIo->GrantTableAddress;\r | |
158 | for (Index = 0; Index < NR_GRANT_FRAMES; Index++) {\r | |
159 | Parameters.domid = DOMID_SELF;\r | |
160 | Parameters.idx = Index;\r | |
161 | Parameters.space = XENMAPSPACE_grant_table;\r | |
162 | Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + Index;\r | |
163 | ReturnCode = XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameters);\r | |
164 | if (ReturnCode != 0) {\r | |
165 | DEBUG ((EFI_D_ERROR,\r | |
166 | "Xen GrantTable, add_to_physmap hypercall error: %Ld\n",\r | |
167 | (INT64)ReturnCode));\r | |
168 | }\r | |
169 | }\r | |
170 | }\r | |
171 | \r | |
172 | VOID\r | |
173 | XenGrantTableDeinit (\r | |
174 | XENBUS_DEVICE *Dev\r | |
175 | )\r | |
176 | {\r | |
177 | INTN ReturnCode, Index;\r | |
178 | xen_remove_from_physmap_t Parameters;\r | |
179 | \r | |
180 | if (GrantTable == NULL) {\r | |
181 | return;\r | |
182 | }\r | |
183 | \r | |
184 | for (Index = NR_GRANT_FRAMES - 1; Index >= 0; Index--) {\r | |
185 | Parameters.domid = DOMID_SELF;\r | |
186 | Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + Index;\r | |
187 | DEBUG ((EFI_D_INFO, "Xen GrantTable, removing %Lx\n",\r | |
188 | (UINT64)Parameters.gpfn));\r | |
189 | ReturnCode = XenHypercallMemoryOp (XENMEM_remove_from_physmap, &Parameters);\r | |
190 | if (ReturnCode != 0) {\r | |
191 | DEBUG ((EFI_D_ERROR,\r | |
192 | "Xen GrantTable, remove_from_physmap hypercall error: %Ld\n",\r | |
193 | (INT64)ReturnCode));\r | |
194 | }\r | |
195 | }\r | |
196 | GrantTable = NULL;\r | |
197 | }\r | |
198 | \r | |
199 | EFI_STATUS\r | |
200 | EFIAPI\r | |
201 | XenBusGrantAccess (\r | |
202 | IN XENBUS_PROTOCOL *This,\r | |
203 | IN domid_t DomainId,\r | |
204 | IN UINTN Frame, // MFN\r | |
205 | IN BOOLEAN ReadOnly,\r | |
206 | OUT grant_ref_t *RefPtr\r | |
207 | )\r | |
208 | {\r | |
209 | *RefPtr = XenGrantTableGrantAccess (DomainId, Frame, ReadOnly);\r | |
210 | return EFI_SUCCESS;\r | |
211 | }\r | |
212 | \r | |
213 | EFI_STATUS\r | |
214 | EFIAPI\r | |
215 | XenBusGrantEndAccess (\r | |
216 | IN XENBUS_PROTOCOL *This,\r | |
217 | IN grant_ref_t Ref\r | |
218 | )\r | |
219 | {\r | |
220 | return XenGrantTableEndAccess (Ref);\r | |
221 | }\r |