qemu-timer: Introduce clock reset notifier

QEMU_CLOCK_HOST is based on the system time which may jump backward in
case the admin or NTP adjusts it. RTC emulations and other device models
can suffer in this case as timers will stall for the period the clock
was tuned back.

This adds a detection mechanism that checks on every host clock readout
if the new time is before the last result. If that is the case a
notifier list is informed. Device models interested in this event can
register a notifier with the clock.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2 files changed
tree: dd73ff536345dad4741b6fab3ccd4112d9fe8215
  1. audio/
  2. block/
  3. bsd-user/
  4. darwin-user/
  5. default-configs/
  6. docs/
  7. fpu/
  8. fsdev/
  9. gdb-xml/
  10. hw/
  11. libcacard/
  12. linux-headers/
  13. linux-user/
  14. net/
  15. pc-bios/
  16. qapi/
  17. qga/
  18. QMP/
  19. roms/
  20. scripts/
  21. slirp/
  22. sysconfigs/
  23. target-alpha/
  24. target-arm/
  25. target-cris/
  26. target-i386/
  27. target-lm32/
  28. target-m68k/
  29. target-microblaze/
  30. target-mips/
  31. target-ppc/
  32. target-s390x/
  33. target-sh4/
  34. target-sparc/
  35. target-unicore32/
  36. tcg/
  37. tests/
  38. ui/
  39. .gitignore
  40. .gitmodules
  41. a.out.h
  42. acl.c
  43. acl.h
  44. aes.c
  45. aes.h
  46. aio.c
  47. alpha-dis.c
  48. alpha.ld
  49. arch_init.c
  50. arch_init.h
  51. arm-dis.c
  52. arm-semi.c
  53. arm.ld
  54. async.c
  55. balloon.c
  56. balloon.h
  57. bitmap.c
  58. bitmap.h
  59. bitops.c
  60. bitops.h
  61. block-migration.c
  62. block-migration.h
  63. block.c
  64. block.h
  65. block_int.h
  66. blockdev.c
  67. blockdev.h
  68. bswap.h
  69. bt-host.c
  70. bt-host.h
  71. bt-vhci.c
  72. buffered_file.c
  73. buffered_file.h
  74. cache-utils.c
  75. cache-utils.h
  76. Changelog
  77. check-qdict.c
  78. check-qfloat.c
  79. check-qint.c
  80. check-qjson.c
  81. check-qlist.c
  82. check-qstring.c
  83. cmd.c
  84. cmd.h
  85. CODING_STYLE
  86. compatfd.c
  87. compatfd.h
  88. compiler.h
  89. config.h
  90. configure
  91. console.c
  92. console.h
  93. COPYING
  94. COPYING.LIB
  95. cpu-all.h
  96. cpu-common.h
  97. cpu-defs.h
  98. cpu-exec.c
  99. cpus.c
  100. cpus.h
  101. cris-dis.c
  102. cursor.c
  103. cursor_hidden.xpm
  104. cursor_left_ptr.xpm
  105. cutils.c
  106. def-helper.h
  107. device_tree.c
  108. device_tree.h
  109. dis-asm.h
  110. disas.c
  111. disas.h
  112. dma-helpers.c
  113. dma.h
  114. dyngen-exec.h
  115. elf.h
  116. envlist.c
  117. envlist.h
  118. error.c
  119. error.h
  120. error_int.h
  121. exec-all.h
  122. exec.c
  123. gdbstub.c
  124. gdbstub.h
  125. gen-icount.h
  126. HACKING
  127. hmp-commands.hx
  128. host-utils.c
  129. host-utils.h
  130. hpet.h
  131. hppa-dis.c
  132. hppa.ld
  133. i386-dis.c
  134. i386.ld
  135. ia64-dis.c
  136. ia64.ld
  137. input.c
  138. iohandler.c
  139. ioport-user.c
  140. ioport.c
  141. ioport.h
  142. iorange.h
  143. iov.c
  144. iov.h
  145. json-lexer.c
  146. json-lexer.h
  147. json-parser.c
  148. json-parser.h
  149. json-streamer.c
  150. json-streamer.h
  151. kvm-all.c
  152. kvm-stub.c
  153. kvm.h
  154. libfdt_env.h
  155. LICENSE
  156. linux-aio.c
  157. m68k-dis.c
  158. m68k-semi.c
  159. m68k.ld
  160. MAINTAINERS
  161. Makefile
  162. Makefile.dis
  163. Makefile.hw
  164. Makefile.objs
  165. Makefile.target
  166. Makefile.user
  167. microblaze-dis.c
  168. migration-exec.c
  169. migration-fd.c
  170. migration-tcp.c
  171. migration-unix.c
  172. migration.c
  173. migration.h
  174. mips-dis.c
  175. mips.ld
  176. module.c
  177. module.h
  178. monitor.c
  179. monitor.h
  180. nbd.c
  181. nbd.h
  182. net.c
  183. net.h
  184. notify.c
  185. notify.h
  186. os-posix.c
  187. os-win32.c
  188. osdep.c
  189. osdep.h
  190. oslib-posix.c
  191. oslib-win32.c
  192. path.c
  193. pci-ids.txt
  194. pflib.c
  195. pflib.h
  196. poison.h
  197. posix-aio-compat.c
  198. ppc-dis.c
  199. ppc.ld
  200. ppc64.ld
  201. qapi-schema-guest.json
  202. qapi-schema-test.json
  203. qbool.c
  204. qbool.h
  205. qdict-test-data.txt
  206. qdict.c
  207. qdict.h
  208. qemu-aio.h
  209. qemu-barrier.h
  210. qemu-char.c
  211. qemu-char.h
  212. qemu-common.h
  213. qemu-config.c
  214. qemu-config.h
  215. qemu-doc.texi
  216. qemu-error.c
  217. qemu-error.h
  218. qemu-ga.c
  219. qemu-img-cmds.hx
  220. qemu-img.c
  221. qemu-img.texi
  222. qemu-io.c
  223. qemu-lock.h
  224. qemu-log.h
  225. qemu-malloc.c
  226. qemu-nbd.c
  227. qemu-nbd.texi
  228. qemu-objects.h
  229. qemu-option.c
  230. qemu-option.h
  231. qemu-options.h
  232. qemu-options.hx
  233. qemu-os-posix.h
  234. qemu-os-win32.h
  235. qemu-progress.c
  236. qemu-queue.h
  237. qemu-sockets.c
  238. qemu-tech.texi
  239. qemu-thread-posix.c
  240. qemu-thread-posix.h
  241. qemu-thread-win32.c
  242. qemu-thread-win32.h
  243. qemu-thread.h
  244. qemu-timer-common.c
  245. qemu-timer.c
  246. qemu-timer.h
  247. qemu-tool.c
  248. qemu-x509.h
  249. qemu.sasl
  250. qemu_socket.h
  251. qerror.c
  252. qerror.h
  253. qfloat.c
  254. qfloat.h
  255. qint.c
  256. qint.h
  257. qjson.c
  258. qjson.h
  259. qlist.c
  260. qlist.h
  261. qmp-commands.hx
  262. qobject.h
  263. qstring.c
  264. qstring.h
  265. range.h
  266. readline.c
  267. readline.h
  268. README
  269. rules.mak
  270. rwhandler.c
  271. rwhandler.h
  272. s390-dis.c
  273. s390.ld
  274. savevm.c
  275. sh4-dis.c
  276. simpletrace.c
  277. simpletrace.h
  278. softmmu-semi.h
  279. softmmu_defs.h
  280. softmmu_exec.h
  281. softmmu_header.h
  282. softmmu_template.h
  283. sparc-dis.c
  284. sparc.ld
  285. sparc64.ld
  286. spice-qemu-char.c
  287. sysemu.h
  288. targphys.h
  289. tcg-runtime.c
  290. test-qmp-commands.c
  291. test-visitor.c
  292. thunk.c
  293. thunk.h
  294. TODO
  295. trace-events
  296. translate-all.c
  297. uboot_image.h
  298. usb-bsd.c
  299. usb-linux.c
  300. usb-redir.c
  301. usb-stub.c
  302. user-exec.c
  303. VERSION
  304. version.rc
  305. vgafont.h
  306. vl.c
  307. x86_64.ld
  308. xen-all.c
  309. xen-mapcache.c
  310. xen-mapcache.h
  311. xen-stub.c