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0fd14246 SS |
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 | |
b26f0cf9 | 12 | SPDX-License-Identifier: BSD-2-Clause-Patent\r |
0fd14246 SS |
13 | **/\r |
14 | #include "XenBusDxe.h"\r | |
15 | \r | |
16 | #include <IndustryStandard/Xen/memory.h>\r | |
17 | \r | |
cd8ff8fd | 18 | #include <Library/XenHypercallLib.h>\r |
e482753b | 19 | #include <Library/SynchronizationLib.h>\r |
0fd14246 SS |
20 | \r |
21 | #include "GrantTable.h"\r | |
0fd14246 SS |
22 | \r |
23 | #define NR_RESERVED_ENTRIES 8\r | |
24 | \r | |
25 | /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */\r | |
26 | #define NR_GRANT_FRAMES 4\r | |
27 | #define NR_GRANT_ENTRIES (NR_GRANT_FRAMES * EFI_PAGE_SIZE / sizeof(grant_entry_v1_t))\r | |
28 | \r | |
29 | STATIC grant_entry_v1_t *GrantTable = NULL;\r | |
30 | STATIC grant_ref_t GrantList[NR_GRANT_ENTRIES];\r | |
31 | STATIC EFI_LOCK mGrantListLock;\r | |
32 | #ifdef GNT_DEBUG\r | |
33 | STATIC BOOLEAN GrantInUseList[NR_GRANT_ENTRIES];\r | |
34 | #endif\r | |
35 | \r | |
36 | STATIC\r | |
37 | VOID\r | |
38 | XenGrantTablePutFreeEntry (\r | |
39 | grant_ref_t Ref\r | |
40 | )\r | |
41 | {\r | |
42 | EfiAcquireLock (&mGrantListLock);\r | |
43 | #ifdef GNT_DEBUG\r | |
44 | ASSERT (GrantInUseList[Ref]);\r | |
45 | GrantInUseList[Ref] = FALSE;\r | |
46 | #endif\r | |
47 | GrantList[Ref] = GrantList[0];\r | |
48 | GrantList[0] = Ref;\r | |
49 | EfiReleaseLock (&mGrantListLock);\r | |
50 | }\r | |
51 | \r | |
52 | STATIC\r | |
53 | grant_ref_t\r | |
54 | XenGrantTableGetFreeEntry (\r | |
55 | VOID\r | |
56 | )\r | |
57 | {\r | |
cec6ad0a | 58 | grant_ref_t Ref;\r |
0fd14246 SS |
59 | \r |
60 | EfiAcquireLock (&mGrantListLock);\r | |
61 | Ref = GrantList[0];\r | |
62 | ASSERT (Ref >= NR_RESERVED_ENTRIES && Ref < NR_GRANT_ENTRIES);\r | |
63 | GrantList[0] = GrantList[Ref];\r | |
64 | #ifdef GNT_DEBUG\r | |
65 | ASSERT (!GrantInUseList[Ref]);\r | |
66 | GrantInUseList[Ref] = TRUE;\r | |
67 | #endif\r | |
68 | EfiReleaseLock (&mGrantListLock);\r | |
69 | return Ref;\r | |
70 | }\r | |
71 | \r | |
72 | STATIC\r | |
73 | grant_ref_t\r | |
74 | XenGrantTableGrantAccess (\r | |
75 | IN domid_t DomainId,\r | |
76 | IN UINTN Frame,\r | |
77 | IN BOOLEAN ReadOnly\r | |
78 | )\r | |
79 | {\r | |
80 | grant_ref_t Ref;\r | |
cec6ad0a | 81 | UINT16 Flags;\r |
0fd14246 SS |
82 | \r |
83 | ASSERT (GrantTable != NULL);\r | |
84 | Ref = XenGrantTableGetFreeEntry ();\r | |
017a4866 | 85 | GrantTable[Ref].frame = (UINT32)Frame;\r |
0fd14246 SS |
86 | GrantTable[Ref].domid = DomainId;\r |
87 | MemoryFence ();\r | |
88 | Flags = GTF_permit_access;\r | |
89 | if (ReadOnly) {\r | |
90 | Flags |= GTF_readonly;\r | |
91 | }\r | |
92 | GrantTable[Ref].flags = Flags;\r | |
93 | \r | |
94 | return Ref;\r | |
95 | }\r | |
96 | \r | |
97 | STATIC\r | |
98 | EFI_STATUS\r | |
99 | XenGrantTableEndAccess (\r | |
100 | grant_ref_t Ref\r | |
101 | )\r | |
102 | {\r | |
103 | UINT16 Flags, OldFlags;\r | |
104 | \r | |
105 | ASSERT (GrantTable != NULL);\r | |
106 | ASSERT (Ref >= NR_RESERVED_ENTRIES && Ref < NR_GRANT_ENTRIES);\r | |
107 | \r | |
108 | OldFlags = GrantTable[Ref].flags;\r | |
109 | do {\r | |
110 | if ((Flags = OldFlags) & (GTF_reading | GTF_writing)) {\r | |
111 | DEBUG ((EFI_D_WARN, "WARNING: g.e. still in use! (%x)\n", Flags));\r | |
112 | return EFI_NOT_READY;\r | |
113 | }\r | |
114 | OldFlags = InterlockedCompareExchange16 (&GrantTable[Ref].flags, Flags, 0);\r | |
115 | } while (OldFlags != Flags);\r | |
116 | \r | |
117 | XenGrantTablePutFreeEntry (Ref);\r | |
118 | return EFI_SUCCESS;\r | |
119 | }\r | |
120 | \r | |
121 | VOID\r | |
122 | XenGrantTableInit (\r | |
d9fdfd85 | 123 | IN XENBUS_DEVICE *Dev\r |
0fd14246 SS |
124 | )\r |
125 | {\r | |
126 | xen_add_to_physmap_t Parameters;\r | |
127 | INTN Index;\r | |
128 | INTN ReturnCode;\r | |
129 | \r | |
130 | #ifdef GNT_DEBUG\r | |
131 | SetMem(GrantInUseList, sizeof (GrantInUseList), 1);\r | |
132 | #endif\r | |
133 | EfiInitializeLock (&mGrantListLock, TPL_NOTIFY);\r | |
134 | for (Index = NR_RESERVED_ENTRIES; Index < NR_GRANT_ENTRIES; Index++) {\r | |
017a4866 | 135 | XenGrantTablePutFreeEntry ((grant_ref_t)Index);\r |
0fd14246 SS |
136 | }\r |
137 | \r | |
d9fdfd85 | 138 | GrantTable = (VOID*)(UINTN) Dev->XenIo->GrantTableAddress;\r |
0fd14246 SS |
139 | for (Index = 0; Index < NR_GRANT_FRAMES; Index++) {\r |
140 | Parameters.domid = DOMID_SELF;\r | |
141 | Parameters.idx = Index;\r | |
142 | Parameters.space = XENMAPSPACE_grant_table;\r | |
d6970b9b | 143 | Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + Index;\r |
bbc3758a | 144 | ReturnCode = XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameters);\r |
0fd14246 | 145 | if (ReturnCode != 0) {\r |
6394c35a LE |
146 | DEBUG ((EFI_D_ERROR,\r |
147 | "Xen GrantTable, add_to_physmap hypercall error: %Ld\n",\r | |
148 | (INT64)ReturnCode));\r | |
0fd14246 SS |
149 | }\r |
150 | }\r | |
151 | }\r | |
152 | \r | |
153 | VOID\r | |
154 | XenGrantTableDeinit (\r | |
155 | XENBUS_DEVICE *Dev\r | |
156 | )\r | |
157 | {\r | |
158 | INTN ReturnCode, Index;\r | |
159 | xen_remove_from_physmap_t Parameters;\r | |
160 | \r | |
161 | if (GrantTable == NULL) {\r | |
162 | return;\r | |
163 | }\r | |
164 | \r | |
165 | for (Index = NR_GRANT_FRAMES - 1; Index >= 0; Index--) {\r | |
166 | Parameters.domid = DOMID_SELF;\r | |
d6970b9b | 167 | Parameters.gpfn = (xen_pfn_t) ((UINTN) GrantTable >> EFI_PAGE_SHIFT) + Index;\r |
6394c35a LE |
168 | DEBUG ((EFI_D_INFO, "Xen GrantTable, removing %Lx\n",\r |
169 | (UINT64)Parameters.gpfn));\r | |
bbc3758a | 170 | ReturnCode = XenHypercallMemoryOp (XENMEM_remove_from_physmap, &Parameters);\r |
0fd14246 | 171 | if (ReturnCode != 0) {\r |
6394c35a LE |
172 | DEBUG ((EFI_D_ERROR,\r |
173 | "Xen GrantTable, remove_from_physmap hypercall error: %Ld\n",\r | |
174 | (INT64)ReturnCode));\r | |
0fd14246 SS |
175 | }\r |
176 | }\r | |
177 | GrantTable = NULL;\r | |
178 | }\r | |
179 | \r | |
180 | EFI_STATUS\r | |
181 | EFIAPI\r | |
182 | XenBusGrantAccess (\r | |
183 | IN XENBUS_PROTOCOL *This,\r | |
184 | IN domid_t DomainId,\r | |
185 | IN UINTN Frame, // MFN\r | |
186 | IN BOOLEAN ReadOnly,\r | |
187 | OUT grant_ref_t *RefPtr\r | |
188 | )\r | |
189 | {\r | |
190 | *RefPtr = XenGrantTableGrantAccess (DomainId, Frame, ReadOnly);\r | |
191 | return EFI_SUCCESS;\r | |
192 | }\r | |
193 | \r | |
194 | EFI_STATUS\r | |
195 | EFIAPI\r | |
196 | XenBusGrantEndAccess (\r | |
197 | IN XENBUS_PROTOCOL *This,\r | |
198 | IN grant_ref_t Ref\r | |
199 | )\r | |
200 | {\r | |
201 | return XenGrantTableEndAccess (Ref);\r | |
202 | }\r |