xref: /openbmc/qemu/util/oslib-win32.c (revision 4f7689f0)
1 /*
2  * os-win32.c
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  * Copyright (c) 2010-2016 Red Hat, Inc.
6  *
7  * QEMU library functions for win32 which are shared between QEMU and
8  * the QEMU tools.
9  *
10  * Permission is hereby granted, free of charge, to any person obtaining a copy
11  * of this software and associated documentation files (the "Software"), to deal
12  * in the Software without restriction, including without limitation the rights
13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14  * copies of the Software, and to permit persons to whom the Software is
15  * furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice shall be included in
18  * all copies or substantial portions of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26  * THE SOFTWARE.
27  */
28 
29 #include "qemu/osdep.h"
30 #include <windows.h>
31 #include "qapi/error.h"
32 #include "qemu/main-loop.h"
33 #include "trace.h"
34 #include "qemu/sockets.h"
35 #include "qemu/cutils.h"
36 #include "qemu/error-report.h"
37 #include <malloc.h>
38 
39 static int get_allocation_granularity(void)
40 {
41     SYSTEM_INFO system_info;
42 
43     GetSystemInfo(&system_info);
44     return system_info.dwAllocationGranularity;
45 }
46 
47 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared,
48                           bool noreserve)
49 {
50     void *ptr;
51 
52     if (noreserve) {
53         /*
54          * We need a MEM_COMMIT before accessing any memory in a MEM_RESERVE
55          * area; we cannot easily mimic POSIX MAP_NORESERVE semantics.
56          */
57         error_report("Skipping reservation of swap space is not supported.");
58         return NULL;
59     }
60 
61     ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
62     trace_qemu_anon_ram_alloc(size, ptr);
63 
64     if (ptr && align) {
65         *align = MAX(get_allocation_granularity(), getpagesize());
66     }
67     return ptr;
68 }
69 
70 void qemu_anon_ram_free(void *ptr, size_t size)
71 {
72     trace_qemu_anon_ram_free(ptr, size);
73     if (ptr) {
74         VirtualFree(ptr, 0, MEM_RELEASE);
75     }
76 }
77 
78 #ifndef _POSIX_THREAD_SAFE_FUNCTIONS
79 /* FIXME: add proper locking */
80 struct tm *gmtime_r(const time_t *timep, struct tm *result)
81 {
82     struct tm *p = gmtime(timep);
83     memset(result, 0, sizeof(*result));
84     if (p) {
85         *result = *p;
86         p = result;
87     }
88     return p;
89 }
90 
91 /* FIXME: add proper locking */
92 struct tm *localtime_r(const time_t *timep, struct tm *result)
93 {
94     struct tm *p = localtime(timep);
95     memset(result, 0, sizeof(*result));
96     if (p) {
97         *result = *p;
98         p = result;
99     }
100     return p;
101 }
102 #endif /* _POSIX_THREAD_SAFE_FUNCTIONS */
103 
104 static int socket_error(void)
105 {
106     switch (WSAGetLastError()) {
107     case 0:
108         return 0;
109     case WSAEINTR:
110         return EINTR;
111     case WSAEINVAL:
112         return EINVAL;
113     case WSA_INVALID_HANDLE:
114         return EBADF;
115     case WSA_NOT_ENOUGH_MEMORY:
116         return ENOMEM;
117     case WSA_INVALID_PARAMETER:
118         return EINVAL;
119     case WSAENAMETOOLONG:
120         return ENAMETOOLONG;
121     case WSAENOTEMPTY:
122         return ENOTEMPTY;
123     case WSAEWOULDBLOCK:
124          /* not using EWOULDBLOCK as we don't want code to have
125           * to check both EWOULDBLOCK and EAGAIN */
126         return EAGAIN;
127     case WSAEINPROGRESS:
128         return EINPROGRESS;
129     case WSAEALREADY:
130         return EALREADY;
131     case WSAENOTSOCK:
132         return ENOTSOCK;
133     case WSAEDESTADDRREQ:
134         return EDESTADDRREQ;
135     case WSAEMSGSIZE:
136         return EMSGSIZE;
137     case WSAEPROTOTYPE:
138         return EPROTOTYPE;
139     case WSAENOPROTOOPT:
140         return ENOPROTOOPT;
141     case WSAEPROTONOSUPPORT:
142         return EPROTONOSUPPORT;
143     case WSAEOPNOTSUPP:
144         return EOPNOTSUPP;
145     case WSAEAFNOSUPPORT:
146         return EAFNOSUPPORT;
147     case WSAEADDRINUSE:
148         return EADDRINUSE;
149     case WSAEADDRNOTAVAIL:
150         return EADDRNOTAVAIL;
151     case WSAENETDOWN:
152         return ENETDOWN;
153     case WSAENETUNREACH:
154         return ENETUNREACH;
155     case WSAENETRESET:
156         return ENETRESET;
157     case WSAECONNABORTED:
158         return ECONNABORTED;
159     case WSAECONNRESET:
160         return ECONNRESET;
161     case WSAENOBUFS:
162         return ENOBUFS;
163     case WSAEISCONN:
164         return EISCONN;
165     case WSAENOTCONN:
166         return ENOTCONN;
167     case WSAETIMEDOUT:
168         return ETIMEDOUT;
169     case WSAECONNREFUSED:
170         return ECONNREFUSED;
171     case WSAELOOP:
172         return ELOOP;
173     case WSAEHOSTUNREACH:
174         return EHOSTUNREACH;
175     default:
176         return EIO;
177     }
178 }
179 
180 void qemu_socket_set_block(int fd)
181 {
182     unsigned long opt = 0;
183     qemu_socket_unselect(fd, NULL);
184     ioctlsocket(fd, FIONBIO, &opt);
185 }
186 
187 int qemu_socket_try_set_nonblock(int fd)
188 {
189     unsigned long opt = 1;
190     if (ioctlsocket(fd, FIONBIO, &opt) != NO_ERROR) {
191         return -socket_error();
192     }
193     return 0;
194 }
195 
196 void qemu_socket_set_nonblock(int fd)
197 {
198     (void)qemu_socket_try_set_nonblock(fd);
199 }
200 
201 int socket_set_fast_reuse(int fd)
202 {
203     /* Enabling the reuse of an endpoint that was used by a socket still in
204      * TIME_WAIT state is usually performed by setting SO_REUSEADDR. On Windows
205      * fast reuse is the default and SO_REUSEADDR does strange things. So we
206      * don't have to do anything here. More info can be found at:
207      * http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621.aspx */
208     return 0;
209 }
210 
211 int inet_aton(const char *cp, struct in_addr *ia)
212 {
213     uint32_t addr = inet_addr(cp);
214     if (addr == 0xffffffff) {
215         return 0;
216     }
217     ia->s_addr = addr;
218     return 1;
219 }
220 
221 void qemu_set_cloexec(int fd)
222 {
223 }
224 
225 int qemu_get_thread_id(void)
226 {
227     return GetCurrentThreadId();
228 }
229 
230 char *
231 qemu_get_local_state_dir(void)
232 {
233     const char * const *data_dirs = g_get_system_data_dirs();
234 
235     g_assert(data_dirs && data_dirs[0]);
236 
237     return g_strdup(data_dirs[0]);
238 }
239 
240 void qemu_set_tty_echo(int fd, bool echo)
241 {
242     HANDLE handle = (HANDLE)_get_osfhandle(fd);
243     DWORD dwMode = 0;
244 
245     if (handle == INVALID_HANDLE_VALUE) {
246         return;
247     }
248 
249     GetConsoleMode(handle, &dwMode);
250 
251     if (echo) {
252         SetConsoleMode(handle, dwMode | ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT);
253     } else {
254         SetConsoleMode(handle,
255                        dwMode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT));
256     }
257 }
258 
259 int getpagesize(void)
260 {
261     SYSTEM_INFO system_info;
262 
263     GetSystemInfo(&system_info);
264     return system_info.dwPageSize;
265 }
266 
267 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
268                        ThreadContext *tc, Error **errp)
269 {
270     int i;
271     size_t pagesize = qemu_real_host_page_size();
272 
273     sz = (sz + pagesize - 1) & -pagesize;
274     for (i = 0; i < sz / pagesize; i++) {
275         memset(area + pagesize * i, 0, 1);
276     }
277 }
278 
279 char *qemu_get_pid_name(pid_t pid)
280 {
281     /* XXX Implement me */
282     abort();
283 }
284 
285 
286 bool qemu_socket_select(int sockfd, WSAEVENT hEventObject,
287                         long lNetworkEvents, Error **errp)
288 {
289     SOCKET s = _get_osfhandle(sockfd);
290 
291     if (errp == NULL) {
292         errp = &error_warn;
293     }
294 
295     if (s == INVALID_SOCKET) {
296         error_setg(errp, "invalid socket fd=%d", sockfd);
297         return false;
298     }
299 
300     if (WSAEventSelect(s, hEventObject, lNetworkEvents) != 0) {
301         error_setg_win32(errp, WSAGetLastError(), "failed to WSAEventSelect()");
302         return false;
303     }
304 
305     return true;
306 }
307 
308 bool qemu_socket_unselect(int sockfd, Error **errp)
309 {
310     return qemu_socket_select(sockfd, NULL, 0, errp);
311 }
312 
313 int qemu_socketpair(int domain, int type, int protocol, int sv[2])
314 {
315     struct sockaddr_un addr = {
316         0,
317     };
318     socklen_t socklen;
319     int listener = -1;
320     int client = -1;
321     int server = -1;
322     g_autofree char *path = NULL;
323     int tmpfd;
324     u_long arg;
325     int ret = -1;
326 
327     g_return_val_if_fail(sv != NULL, -1);
328 
329     addr.sun_family = AF_UNIX;
330     socklen = sizeof(addr);
331 
332     tmpfd = g_file_open_tmp(NULL, &path, NULL);
333     if (tmpfd == -1 || !path) {
334         errno = EACCES;
335         goto out;
336     }
337 
338     close(tmpfd);
339 
340     if (strlen(path) >= sizeof(addr.sun_path)) {
341         errno = EINVAL;
342         goto out;
343     }
344 
345     strncpy(addr.sun_path, path, sizeof(addr.sun_path) - 1);
346 
347     listener = socket(domain, type, protocol);
348     if (listener == -1) {
349         goto out;
350     }
351 
352     if (DeleteFile(path) == 0 && GetLastError() != ERROR_FILE_NOT_FOUND) {
353         errno = EACCES;
354         goto out;
355     }
356     g_clear_pointer(&path, g_free);
357 
358     if (bind(listener, (struct sockaddr *)&addr, socklen) == -1) {
359         goto out;
360     }
361 
362     if (listen(listener, 1) == -1) {
363         goto out;
364     }
365 
366     client = socket(domain, type, protocol);
367     if (client == -1) {
368         goto out;
369     }
370 
371     arg = 1;
372     if (ioctlsocket(client, FIONBIO, &arg) != NO_ERROR) {
373         goto out;
374     }
375 
376     if (connect(client, (struct sockaddr *)&addr, socklen) == -1 &&
377         WSAGetLastError() != WSAEWOULDBLOCK) {
378         goto out;
379     }
380 
381     server = accept(listener, NULL, NULL);
382     if (server == -1) {
383         goto out;
384     }
385 
386     arg = 0;
387     if (ioctlsocket(client, FIONBIO, &arg) != NO_ERROR) {
388         goto out;
389     }
390 
391     arg = 0;
392     if (ioctlsocket(client, SIO_AF_UNIX_GETPEERPID, &arg) != NO_ERROR) {
393         goto out;
394     }
395 
396     if (arg != GetCurrentProcessId()) {
397         errno = EPERM;
398         goto out;
399     }
400 
401     sv[0] = server;
402     server = -1;
403     sv[1] = client;
404     client = -1;
405     ret = 0;
406 
407 out:
408     if (listener != -1) {
409         close(listener);
410     }
411     if (client != -1) {
412         close(client);
413     }
414     if (server != -1) {
415         close(server);
416     }
417     if (path) {
418         DeleteFile(path);
419     }
420     return ret;
421 }
422 
423 #undef connect
424 int qemu_connect_wrap(int sockfd, const struct sockaddr *addr,
425                       socklen_t addrlen)
426 {
427     int ret;
428     SOCKET s = _get_osfhandle(sockfd);
429 
430     if (s == INVALID_SOCKET) {
431         return -1;
432     }
433 
434     ret = connect(s, addr, addrlen);
435     if (ret < 0) {
436         if (WSAGetLastError() == WSAEWOULDBLOCK) {
437             errno = EINPROGRESS;
438         } else {
439             errno = socket_error();
440         }
441     }
442     return ret;
443 }
444 
445 
446 #undef listen
447 int qemu_listen_wrap(int sockfd, int backlog)
448 {
449     int ret;
450     SOCKET s = _get_osfhandle(sockfd);
451 
452     if (s == INVALID_SOCKET) {
453         return -1;
454     }
455 
456     ret = listen(s, backlog);
457     if (ret < 0) {
458         errno = socket_error();
459     }
460     return ret;
461 }
462 
463 
464 #undef bind
465 int qemu_bind_wrap(int sockfd, const struct sockaddr *addr,
466                    socklen_t addrlen)
467 {
468     int ret;
469     SOCKET s = _get_osfhandle(sockfd);
470 
471     if (s == INVALID_SOCKET) {
472         return -1;
473     }
474 
475     ret = bind(s, addr, addrlen);
476     if (ret < 0) {
477         errno = socket_error();
478     }
479     return ret;
480 }
481 
482 QEMU_USED EXCEPTION_DISPOSITION
483 win32_close_exception_handler(struct _EXCEPTION_RECORD *exception_record,
484                               void *registration, struct _CONTEXT *context,
485                               void *dispatcher)
486 {
487     return EXCEPTION_EXECUTE_HANDLER;
488 }
489 
490 #undef close
491 int qemu_close_socket_osfhandle(int fd)
492 {
493     SOCKET s = _get_osfhandle(fd);
494     DWORD flags = 0;
495 
496     /*
497      * If we were to just call _close on the descriptor, it would close the
498      * HANDLE, but it wouldn't free any of the resources associated to the
499      * SOCKET, and we can't call _close after calling closesocket, because
500      * closesocket has already closed the HANDLE, and _close would attempt to
501      * close the HANDLE again, resulting in a double free. We can however
502      * protect the HANDLE from actually being closed long enough to close the
503      * file descriptor, then close the socket itself.
504      */
505     if (!GetHandleInformation((HANDLE)s, &flags)) {
506         errno = EACCES;
507         return -1;
508     }
509 
510     if (!SetHandleInformation((HANDLE)s, HANDLE_FLAG_PROTECT_FROM_CLOSE, HANDLE_FLAG_PROTECT_FROM_CLOSE)) {
511         errno = EACCES;
512         return -1;
513     }
514 
515     __try1(win32_close_exception_handler) {
516         /*
517          * close() returns EBADF since we PROTECT_FROM_CLOSE the underlying
518          * handle, but the FD is actually freed
519          */
520         if (close(fd) < 0 && errno != EBADF) {
521             return -1;
522         }
523     }
524     __except1 {
525     }
526 
527     if (!SetHandleInformation((HANDLE)s, flags, flags)) {
528         errno = EACCES;
529         return -1;
530     }
531 
532     return 0;
533 }
534 
535 int qemu_close_wrap(int fd)
536 {
537     SOCKET s = INVALID_SOCKET;
538     int ret = -1;
539 
540     if (!fd_is_socket(fd)) {
541         return close(fd);
542     }
543 
544     s = _get_osfhandle(fd);
545     qemu_close_socket_osfhandle(fd);
546 
547     ret = closesocket(s);
548     if (ret < 0) {
549         errno = socket_error();
550     }
551 
552     return ret;
553 }
554 
555 
556 #undef socket
557 int qemu_socket_wrap(int domain, int type, int protocol)
558 {
559     SOCKET s;
560     int fd;
561 
562     s = socket(domain, type, protocol);
563     if (s == -1) {
564         errno = socket_error();
565         return -1;
566     }
567 
568     fd = _open_osfhandle(s, _O_BINARY);
569     if (fd < 0) {
570         closesocket(s);
571         /* _open_osfhandle may not set errno, and closesocket() may override it */
572         errno = ENOMEM;
573     }
574 
575     return fd;
576 }
577 
578 
579 #undef accept
580 int qemu_accept_wrap(int sockfd, struct sockaddr *addr,
581                      socklen_t *addrlen)
582 {
583     int fd;
584     SOCKET s = _get_osfhandle(sockfd);
585 
586     if (s == INVALID_SOCKET) {
587         return -1;
588     }
589 
590     s = accept(s, addr, addrlen);
591     if (s == -1) {
592         errno = socket_error();
593         return -1;
594     }
595 
596     fd = _open_osfhandle(s, _O_BINARY);
597     if (fd < 0) {
598         closesocket(s);
599         /* _open_osfhandle may not set errno, and closesocket() may override it */
600         errno = ENOMEM;
601     }
602 
603     return fd;
604 }
605 
606 
607 #undef shutdown
608 int qemu_shutdown_wrap(int sockfd, int how)
609 {
610     int ret;
611     SOCKET s = _get_osfhandle(sockfd);
612 
613     if (s == INVALID_SOCKET) {
614         return -1;
615     }
616 
617     ret = shutdown(s, how);
618     if (ret < 0) {
619         errno = socket_error();
620     }
621     return ret;
622 }
623 
624 
625 #undef ioctlsocket
626 int qemu_ioctlsocket_wrap(int fd, int req, void *val)
627 {
628     int ret;
629     SOCKET s = _get_osfhandle(fd);
630 
631     if (s == INVALID_SOCKET) {
632         return -1;
633     }
634 
635     ret = ioctlsocket(s, req, val);
636     if (ret < 0) {
637         errno = socket_error();
638     }
639     return ret;
640 }
641 
642 
643 #undef getsockopt
644 int qemu_getsockopt_wrap(int sockfd, int level, int optname,
645                          void *optval, socklen_t *optlen)
646 {
647     int ret;
648     SOCKET s = _get_osfhandle(sockfd);
649 
650     if (s == INVALID_SOCKET) {
651         return -1;
652     }
653 
654     ret = getsockopt(s, level, optname, optval, optlen);
655     if (ret < 0) {
656         errno = socket_error();
657     }
658     return ret;
659 }
660 
661 
662 #undef setsockopt
663 int qemu_setsockopt_wrap(int sockfd, int level, int optname,
664                          const void *optval, socklen_t optlen)
665 {
666     int ret;
667     SOCKET s = _get_osfhandle(sockfd);
668 
669     if (s == INVALID_SOCKET) {
670         return -1;
671     }
672 
673     ret = setsockopt(s, level, optname, optval, optlen);
674     if (ret < 0) {
675         errno = socket_error();
676     }
677     return ret;
678 }
679 
680 
681 #undef getpeername
682 int qemu_getpeername_wrap(int sockfd, struct sockaddr *addr,
683                           socklen_t *addrlen)
684 {
685     int ret;
686     SOCKET s = _get_osfhandle(sockfd);
687 
688     if (s == INVALID_SOCKET) {
689         return -1;
690     }
691 
692     ret = getpeername(s, addr, addrlen);
693     if (ret < 0) {
694         errno = socket_error();
695     }
696     return ret;
697 }
698 
699 
700 #undef getsockname
701 int qemu_getsockname_wrap(int sockfd, struct sockaddr *addr,
702                           socklen_t *addrlen)
703 {
704     int ret;
705     SOCKET s = _get_osfhandle(sockfd);
706 
707     if (s == INVALID_SOCKET) {
708         return -1;
709     }
710 
711     ret = getsockname(s, addr, addrlen);
712     if (ret < 0) {
713         errno = socket_error();
714     }
715     return ret;
716 }
717 
718 
719 #undef send
720 ssize_t qemu_send_wrap(int sockfd, const void *buf, size_t len, int flags)
721 {
722     int ret;
723     SOCKET s = _get_osfhandle(sockfd);
724 
725     if (s == INVALID_SOCKET) {
726         return -1;
727     }
728 
729     ret = send(s, buf, len, flags);
730     if (ret < 0) {
731         errno = socket_error();
732     }
733     return ret;
734 }
735 
736 
737 #undef sendto
738 ssize_t qemu_sendto_wrap(int sockfd, const void *buf, size_t len, int flags,
739                          const struct sockaddr *addr, socklen_t addrlen)
740 {
741     int ret;
742     SOCKET s = _get_osfhandle(sockfd);
743 
744     if (s == INVALID_SOCKET) {
745         return -1;
746     }
747 
748     ret = sendto(s, buf, len, flags, addr, addrlen);
749     if (ret < 0) {
750         errno = socket_error();
751     }
752     return ret;
753 }
754 
755 
756 #undef recv
757 ssize_t qemu_recv_wrap(int sockfd, void *buf, size_t len, int flags)
758 {
759     int ret;
760     SOCKET s = _get_osfhandle(sockfd);
761 
762     if (s == INVALID_SOCKET) {
763         return -1;
764     }
765 
766     ret = recv(s, buf, len, flags);
767     if (ret < 0) {
768         errno = socket_error();
769     }
770     return ret;
771 }
772 
773 
774 #undef recvfrom
775 ssize_t qemu_recvfrom_wrap(int sockfd, void *buf, size_t len, int flags,
776                            struct sockaddr *addr, socklen_t *addrlen)
777 {
778     int ret;
779     SOCKET s = _get_osfhandle(sockfd);
780 
781     if (s == INVALID_SOCKET) {
782         return -1;
783     }
784 
785     ret = recvfrom(s, buf, len, flags, addr, addrlen);
786     if (ret < 0) {
787         errno = socket_error();
788     }
789     return ret;
790 }
791 
792 bool qemu_write_pidfile(const char *filename, Error **errp)
793 {
794     char buffer[128];
795     int len;
796     HANDLE file;
797     OVERLAPPED overlap;
798     BOOL ret;
799     memset(&overlap, 0, sizeof(overlap));
800 
801     file = CreateFile(filename, GENERIC_WRITE, FILE_SHARE_READ, NULL,
802                       OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
803 
804     if (file == INVALID_HANDLE_VALUE) {
805         error_setg(errp, "Failed to create PID file");
806         return false;
807     }
808     len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", (pid_t)getpid());
809     ret = WriteFile(file, (LPCVOID)buffer, (DWORD)len,
810                     NULL, &overlap);
811     CloseHandle(file);
812     if (ret == 0) {
813         error_setg(errp, "Failed to write PID file");
814         return false;
815     }
816     return true;
817 }
818 
819 size_t qemu_get_host_physmem(void)
820 {
821     MEMORYSTATUSEX statex;
822     statex.dwLength = sizeof(statex);
823 
824     if (GlobalMemoryStatusEx(&statex)) {
825         return statex.ullTotalPhys;
826     }
827     return 0;
828 }
829 
830 int qemu_msync(void *addr, size_t length, int fd)
831 {
832     /**
833      * Perform the sync based on the file descriptor
834      * The sync range will most probably be wider than the one
835      * requested - but it will still get the job done
836      */
837     return qemu_fdatasync(fd);
838 }
839 
840 void *qemu_win32_map_alloc(size_t size, HANDLE *h, Error **errp)
841 {
842     void *bits;
843 
844     trace_win32_map_alloc(size);
845 
846     *h = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE, 0,
847                           size, NULL);
848     if (*h == NULL) {
849         error_setg_win32(errp, GetLastError(), "Failed to CreateFileMapping");
850         return NULL;
851     }
852 
853     bits = MapViewOfFile(*h, FILE_MAP_ALL_ACCESS, 0, 0, size);
854     if (bits == NULL) {
855         error_setg_win32(errp, GetLastError(), "Failed to MapViewOfFile");
856         CloseHandle(*h);
857         return NULL;
858     }
859 
860     return bits;
861 }
862 
863 void qemu_win32_map_free(void *ptr, HANDLE h, Error **errp)
864 {
865     trace_win32_map_free(ptr, h);
866 
867     if (UnmapViewOfFile(ptr) == 0) {
868         error_setg_win32(errp, GetLastError(), "Failed to UnmapViewOfFile");
869     }
870     CloseHandle(h);
871 }
872