1  /******************************************************************************
2  *
3  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
4  * Use is subject to license terms.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation;
9  * version 2.1 of the License.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <errno.h>
21 #include <fcntl.h>
22 #include <stdint.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26 
27 #include <sys/mman.h>
28 #include <sys/ioctl.h>
29 
30 #include "private.h"
31 
32 #define PRIVCMD_DEV     "/dev/xen/privcmd"
33 
osdep_xenforeignmemory_open(xenforeignmemory_handle * fmem)34 int osdep_xenforeignmemory_open(xenforeignmemory_handle *fmem)
35 {
36     int fd = open(PRIVCMD_DEV, O_RDWR|O_CLOEXEC);
37 
38     if ( fd == -1 )
39     {
40         PERROR("Could not obtain handle on privileged command interface "
41                PRIVCMD_DEV);
42         return -1;
43     }
44 
45     fmem->fd = fd;
46     return 0;
47 }
48 
osdep_xenforeignmemory_close(xenforeignmemory_handle * fmem)49 int osdep_xenforeignmemory_close(xenforeignmemory_handle *fmem)
50 {
51     int fd = fmem->fd;
52     if ( fd == -1 )
53         return 0;
54     return close(fd);
55 }
56 
osdep_xenforeignmemory_map(xenforeignmemory_handle * fmem,uint32_t dom,void * addr,int prot,int flags,size_t num,const xen_pfn_t arr[],int err[])57 void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
58                                  uint32_t dom, void *addr,
59                                  int prot, int flags, size_t num,
60                                  const xen_pfn_t arr[/*num*/], int err[/*num*/])
61 {
62     int fd = fmem->fd;
63     privcmd_mmapbatch_t ioctlx;
64     int rc;
65 
66     addr = mmap(addr, num << XC_PAGE_SHIFT, prot, flags | MAP_SHARED, fd, 0);
67     if ( addr == MAP_FAILED )
68         return NULL;
69 
70     ioctlx.num = num;
71     ioctlx.dom = dom;
72     ioctlx.addr = (unsigned long)addr;
73     ioctlx.arr = arr;
74     ioctlx.err = err;
75 
76     rc = ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH, &ioctlx);
77     if ( rc < 0 )
78     {
79         int saved_errno = errno;
80 
81         (void)munmap(addr, num << XC_PAGE_SHIFT);
82         errno = saved_errno;
83         return NULL;
84     }
85 
86     return addr;
87 }
88 
osdep_xenforeignmemory_unmap(xenforeignmemory_handle * fmem,void * addr,size_t num)89 int osdep_xenforeignmemory_unmap(xenforeignmemory_handle *fmem,
90                                  void *addr, size_t num)
91 {
92     return munmap(addr, num << XC_PAGE_SHIFT);
93 }
94 
osdep_xenforeignmemory_restrict(xenforeignmemory_handle * fmem,domid_t domid)95 int osdep_xenforeignmemory_restrict(xenforeignmemory_handle *fmem,
96                                     domid_t domid)
97 {
98     return ioctl(fmem->fd, IOCTL_PRIVCMD_RESTRICT, &domid);
99 }
100 
osdep_xenforeignmemory_unmap_resource(xenforeignmemory_handle * fmem,xenforeignmemory_resource_handle * fres)101 int osdep_xenforeignmemory_unmap_resource(xenforeignmemory_handle *fmem,
102                                         xenforeignmemory_resource_handle *fres)
103 {
104     return fres ? munmap(fres->addr, fres->nr_frames << XC_PAGE_SHIFT) : 0;
105 }
106 
osdep_xenforeignmemory_map_resource(xenforeignmemory_handle * fmem,xenforeignmemory_resource_handle * fres)107 int osdep_xenforeignmemory_map_resource(xenforeignmemory_handle *fmem,
108                                         xenforeignmemory_resource_handle *fres)
109 {
110     privcmd_mmap_resource_t mr = {
111         .dom = fres->domid,
112         .type = fres->type,
113         .id = fres->id,
114         .idx = fres->frame,
115         .num = fres->nr_frames,
116     };
117     int rc;
118 
119     if ( !fres->addr && !fres->nr_frames )
120         /* Request for resource size.  Skip mmap(). */
121         goto skip_mmap;
122 
123     fres->addr = mmap(fres->addr, fres->nr_frames << XC_PAGE_SHIFT,
124                       fres->prot, fres->flags | MAP_SHARED, fmem->fd, 0);
125     if ( fres->addr == MAP_FAILED )
126         return -1;
127 
128     mr.addr = (uintptr_t)fres->addr;
129 
130  skip_mmap:
131     rc = ioctl(fmem->fd, IOCTL_PRIVCMD_MMAP_RESOURCE, &mr);
132     if ( rc )
133     {
134         int saved_errno;
135 
136         if ( errno == ENOSYS )
137             errno = EOPNOTSUPP;
138 
139         if ( fres->addr )
140         {
141             saved_errno = errno;
142             osdep_xenforeignmemory_unmap_resource(fmem, fres);
143             errno = saved_errno;
144         }
145 
146         return -1;
147     }
148 
149     /* If requesting size, copy back. */
150     if ( !fres->addr )
151         fres->nr_frames = mr.num;
152 
153     return 0;
154 }
155 
156 /*
157  * Local variables:
158  * mode: C
159  * c-file-style: "BSD"
160  * c-basic-offset: 4
161  * tab-width: 4
162  * indent-tabs-mode: nil
163  * End:
164  */
165