]>
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 | SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
13 | **/\r | |
14 | #include "XenBusDxe.h"\r | |
15 | \r | |
16 | #include <IndustryStandard/Xen/memory.h>\r | |
17 | \r | |
18 | #include <Library/XenHypercallLib.h>\r | |
19 | #include <Library/SynchronizationLib.h>\r | |
20 | \r | |
21 | #include "GrantTable.h"\r | |
22 | \r | |
23 | #define NR_RESERVED_ENTRIES 8\r | |
24 | \r | |
25 | #define NR_GRANT_FRAMES (FixedPcdGet32 (PcdXenGrantFrames))\r | |
26 | #define NR_GRANT_ENTRIES (NR_GRANT_FRAMES * EFI_PAGE_SIZE / sizeof(grant_entry_v1_t))\r | |
27 | \r | |
28 | STATIC grant_entry_v1_t *GrantTable = NULL;\r | |
29 | STATIC grant_ref_t GrantList[NR_GRANT_ENTRIES];\r | |
30 | STATIC EFI_LOCK mGrantListLock;\r | |
31 | #ifdef GNT_DEBUG\r | |
32 | STATIC BOOLEAN GrantInUseList[NR_GRANT_ENTRIES];\r | |
33 | #endif\r | |
34 | \r | |
35 | STATIC\r | |
36 | VOID\r | |
37 | XenGrantTablePutFreeEntry (\r | |
38 | grant_ref_t Ref\r | |
39 | )\r | |
40 | {\r | |
41 | EfiAcquireLock (&mGrantListLock);\r | |
42 | #ifdef GNT_DEBUG\r | |
43 | ASSERT (GrantInUseList[Ref]);\r | |
44 | GrantInUseList[Ref] = FALSE;\r | |
45 | #endif\r | |
46 | GrantList[Ref] = GrantList[0];\r | |
47 | GrantList[0] = Ref;\r | |
48 | EfiReleaseLock (&mGrantListLock);\r | |
49 | }\r | |
50 | \r | |
51 | STATIC\r | |
52 | grant_ref_t\r | |
53 | XenGrantTableGetFreeEntry (\r | |
54 | VOID\r | |
55 | )\r | |
56 | {\r | |
57 | grant_ref_t Ref;\r | |
58 | \r | |
59 | EfiAcquireLock (&mGrantListLock);\r | |
60 | Ref = GrantList[0];\r | |
61 | ASSERT (Ref >= NR_RESERVED_ENTRIES && Ref < NR_GRANT_ENTRIES);\r | |
62 | GrantList[0] = GrantList[Ref];\r | |
63 | #ifdef GNT_DEBUG\r | |
64 | ASSERT (!GrantInUseList[Ref]);\r | |
65 | GrantInUseList[Ref] = TRUE;\r | |
66 | #endif\r | |
67 | EfiReleaseLock (&mGrantListLock);\r | |
68 | return Ref;\r | |
69 | }\r | |
70 | \r | |
71 | STATIC\r | |
72 | grant_ref_t\r | |
73 | XenGrantTableGrantAccess (\r | |
74 | IN domid_t DomainId,\r | |
75 | IN UINTN Frame,\r | |
76 | IN BOOLEAN ReadOnly\r | |
77 | )\r | |
78 | {\r | |
79 | grant_ref_t Ref;\r | |
80 | UINT16 Flags;\r | |
81 | \r | |
82 | ASSERT (GrantTable != NULL);\r | |
83 | Ref = XenGrantTableGetFreeEntry ();\r | |
84 | GrantTable[Ref].frame = (UINT32)Frame;\r | |
85 | GrantTable[Ref].domid = DomainId;\r | |
86 | MemoryFence ();\r | |
87 | Flags = GTF_permit_access;\r | |
88 | if (ReadOnly) {\r | |
89 | Flags |= GTF_readonly;\r | |
90 | }\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 ((DEBUG_WARN, "WARNING: g.e. still in use! (%x)\n", Flags));\r | |
112 | return EFI_NOT_READY;\r | |
113 | }\r | |
114 | \r | |
115 | OldFlags = InterlockedCompareExchange16 (&GrantTable[Ref].flags, Flags, 0);\r | |
116 | } while (OldFlags != Flags);\r | |
117 | \r | |
118 | XenGrantTablePutFreeEntry (Ref);\r | |
119 | return EFI_SUCCESS;\r | |
120 | }\r | |
121 | \r | |
122 | VOID\r | |
123 | XenGrantTableInit (\r | |
124 | IN XENBUS_DEVICE *Dev\r | |
125 | )\r | |
126 | {\r | |
127 | xen_add_to_physmap_t Parameters;\r | |
128 | INTN Index;\r | |
129 | INTN ReturnCode;\r | |
130 | \r | |
131 | #ifdef GNT_DEBUG\r | |
132 | SetMem (GrantInUseList, sizeof (GrantInUseList), 1);\r | |
133 | #endif\r | |
134 | EfiInitializeLock (&mGrantListLock, TPL_NOTIFY);\r | |
135 | for (Index = NR_RESERVED_ENTRIES; Index < NR_GRANT_ENTRIES; Index++) {\r | |
136 | XenGrantTablePutFreeEntry ((grant_ref_t)Index);\r | |
137 | }\r | |
138 | \r | |
139 | GrantTable = (VOID *)(UINTN)Dev->XenIo->GrantTableAddress;\r | |
140 | for (Index = 0; Index < NR_GRANT_FRAMES; Index++) {\r | |
141 | Parameters.domid = DOMID_SELF;\r | |
142 | Parameters.idx = Index;\r | |
143 | Parameters.space = XENMAPSPACE_grant_table;\r | |
144 | Parameters.gpfn = (xen_pfn_t)((UINTN)GrantTable >> EFI_PAGE_SHIFT) + Index;\r | |
145 | ReturnCode = XenHypercallMemoryOp (XENMEM_add_to_physmap, &Parameters);\r | |
146 | if (ReturnCode != 0) {\r | |
147 | DEBUG ((\r | |
148 | DEBUG_ERROR,\r | |
149 | "Xen GrantTable, add_to_physmap hypercall error: %Ld\n",\r | |
150 | (INT64)ReturnCode\r | |
151 | ));\r | |
152 | }\r | |
153 | }\r | |
154 | }\r | |
155 | \r | |
156 | VOID\r | |
157 | XenGrantTableDeinit (\r | |
158 | XENBUS_DEVICE *Dev\r | |
159 | )\r | |
160 | {\r | |
161 | INTN ReturnCode, Index;\r | |
162 | xen_remove_from_physmap_t Parameters;\r | |
163 | \r | |
164 | if (GrantTable == NULL) {\r | |
165 | return;\r | |
166 | }\r | |
167 | \r | |
168 | for (Index = NR_GRANT_FRAMES - 1; Index >= 0; Index--) {\r | |
169 | Parameters.domid = DOMID_SELF;\r | |
170 | Parameters.gpfn = (xen_pfn_t)((UINTN)GrantTable >> EFI_PAGE_SHIFT) + Index;\r | |
171 | DEBUG ((\r | |
172 | DEBUG_INFO,\r | |
173 | "Xen GrantTable, removing %Lx\n",\r | |
174 | (UINT64)Parameters.gpfn\r | |
175 | ));\r | |
176 | ReturnCode = XenHypercallMemoryOp (XENMEM_remove_from_physmap, &Parameters);\r | |
177 | if (ReturnCode != 0) {\r | |
178 | DEBUG ((\r | |
179 | DEBUG_ERROR,\r | |
180 | "Xen GrantTable, remove_from_physmap hypercall error: %Ld\n",\r | |
181 | (INT64)ReturnCode\r | |
182 | ));\r | |
183 | }\r | |
184 | }\r | |
185 | \r | |
186 | GrantTable = NULL;\r | |
187 | }\r | |
188 | \r | |
189 | EFI_STATUS\r | |
190 | EFIAPI\r | |
191 | XenBusGrantAccess (\r | |
192 | IN XENBUS_PROTOCOL *This,\r | |
193 | IN domid_t DomainId,\r | |
194 | IN UINTN Frame, // MFN\r | |
195 | IN BOOLEAN ReadOnly,\r | |
196 | OUT grant_ref_t *RefPtr\r | |
197 | )\r | |
198 | {\r | |
199 | *RefPtr = XenGrantTableGrantAccess (DomainId, Frame, ReadOnly);\r | |
200 | return EFI_SUCCESS;\r | |
201 | }\r | |
202 | \r | |
203 | EFI_STATUS\r | |
204 | EFIAPI\r | |
205 | XenBusGrantEndAccess (\r | |
206 | IN XENBUS_PROTOCOL *This,\r | |
207 | IN grant_ref_t Ref\r | |
208 | )\r | |
209 | {\r | |
210 | return XenGrantTableEndAccess (Ref);\r | |
211 | }\r |