kvm: Fix race between timer signals and vcpu entry under !IOTHREAD

Found by Stefan Hajnoczi: There is a race in kvm_cpu_exec between
checking for exit_request on vcpu entry and timer signals arriving
before KVM starts to catch them. Plug it by blocking both timer related
signals also on !CONFIG_IOTHREAD and process those via signalfd.

As this fix depends on real signalfd support (otherwise the timer
signals only kick the compat helper thread, and the main thread hangs),
we need to detect the invalid constellation and abort configure.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
CC: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2 files changed
tree: 5324fd7b9ecd4997d8f5d83ac9c26635329346eb
  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. linux-user/
  12. net/
  13. pc-bios/
  14. QMP/
  15. roms/
  16. scripts/
  17. slirp/
  18. sysconfigs/
  19. target-alpha/
  20. target-arm/
  21. target-cris/
  22. target-i386/
  23. target-m68k/
  24. target-microblaze/
  25. target-mips/
  26. target-ppc/
  27. target-s390x/
  28. target-sh4/
  29. target-sparc/
  30. tcg/
  31. tests/
  32. ui/
  33. .gitignore
  34. .gitmodules
  35. a.out.h
  36. acl.c
  37. acl.h
  38. aes.c
  39. aes.h
  40. aio.c
  41. alpha-dis.c
  42. alpha.ld
  43. arch_init.c
  44. arch_init.h
  45. arm-dis.c
  46. arm-semi.c
  47. arm.ld
  48. async.c
  49. balloon.c
  50. balloon.h
  51. block-migration.c
  52. block-migration.h
  53. block.c
  54. block.h
  55. block_int.h
  56. blockdev.c
  57. blockdev.h
  58. bswap.h
  59. bt-host.c
  60. bt-host.h
  61. bt-vhci.c
  62. buffered_file.c
  63. buffered_file.h
  64. cache-utils.c
  65. cache-utils.h
  66. Changelog
  67. check-qdict.c
  68. check-qfloat.c
  69. check-qint.c
  70. check-qjson.c
  71. check-qlist.c
  72. check-qstring.c
  73. cmd.c
  74. cmd.h
  75. CODING_STYLE
  76. compatfd.c
  77. compatfd.h
  78. config.h
  79. configure
  80. console.c
  81. console.h
  82. COPYING
  83. COPYING.LIB
  84. cpu-all.h
  85. cpu-common.h
  86. cpu-defs.h
  87. cpu-exec.c
  88. cpus.c
  89. cpus.h
  90. cris-dis.c
  91. cursor.c
  92. cursor_hidden.xpm
  93. cursor_left_ptr.xpm
  94. cutils.c
  95. def-helper.h
  96. device_tree.c
  97. device_tree.h
  98. dis-asm.h
  99. disas.c
  100. disas.h
  101. dma-helpers.c
  102. dma.h
  103. dyngen-exec.h
  104. elf.h
  105. envlist.c
  106. envlist.h
  107. exec-all.h
  108. exec.c
  109. gdbstub.c
  110. gdbstub.h
  111. gen-icount.h
  112. HACKING
  113. hmp-commands.hx
  114. host-utils.c
  115. host-utils.h
  116. hpet.h
  117. hppa-dis.c
  118. hppa.ld
  119. i386-dis.c
  120. i386.ld
  121. ia64-dis.c
  122. ia64.ld
  123. input.c
  124. ioport-user.c
  125. ioport.c
  126. ioport.h
  127. iorange.h
  128. iov.c
  129. iov.h
  130. json-lexer.c
  131. json-lexer.h
  132. json-parser.c
  133. json-parser.h
  134. json-streamer.c
  135. json-streamer.h
  136. kvm-all.c
  137. kvm-stub.c
  138. kvm.h
  139. libfdt_env.h
  140. LICENSE
  141. linux-aio.c
  142. m68k-dis.c
  143. m68k-semi.c
  144. m68k.ld
  145. MAINTAINERS
  146. Makefile
  147. Makefile.dis
  148. Makefile.hw
  149. Makefile.objs
  150. Makefile.target
  151. Makefile.user
  152. microblaze-dis.c
  153. migration-exec.c
  154. migration-fd.c
  155. migration-tcp.c
  156. migration-unix.c
  157. migration.c
  158. migration.h
  159. mips-dis.c
  160. mips.ld
  161. module.c
  162. module.h
  163. monitor.c
  164. monitor.h
  165. nbd.c
  166. nbd.h
  167. net-checksum.c
  168. net.c
  169. net.h
  170. notify.c
  171. notify.h
  172. os-posix.c
  173. os-win32.c
  174. osdep.c
  175. osdep.h
  176. oslib-posix.c
  177. oslib-win32.c
  178. path.c
  179. pci-ids.txt
  180. pflib.c
  181. pflib.h
  182. poison.h
  183. posix-aio-compat.c
  184. ppc-dis.c
  185. ppc.ld
  186. ppc64.ld
  187. qbool.c
  188. qbool.h
  189. qdict-test-data.txt
  190. qdict.c
  191. qdict.h
  192. qemu-aio.h
  193. qemu-barrier.h
  194. qemu-char.c
  195. qemu-char.h
  196. qemu-common.h
  197. qemu-config.c
  198. qemu-config.h
  199. qemu-doc.texi
  200. qemu-error.c
  201. qemu-error.h
  202. qemu-img-cmds.hx
  203. qemu-img.c
  204. qemu-img.texi
  205. qemu-io.c
  206. qemu-lock.h
  207. qemu-log.h
  208. qemu-malloc.c
  209. qemu-nbd.c
  210. qemu-nbd.texi
  211. qemu-objects.h
  212. qemu-option.c
  213. qemu-option.h
  214. qemu-options.h
  215. qemu-options.hx
  216. qemu-os-posix.h
  217. qemu-os-win32.h
  218. qemu-queue.h
  219. qemu-sockets.c
  220. qemu-tech.texi
  221. qemu-thread.c
  222. qemu-thread.h
  223. qemu-timer-common.c
  224. qemu-timer.c
  225. qemu-timer.h
  226. qemu-tool.c
  227. qemu-x509.h
  228. qemu.sasl
  229. qemu_socket.h
  230. qerror.c
  231. qerror.h
  232. qfloat.c
  233. qfloat.h
  234. qint.c
  235. qint.h
  236. qjson.c
  237. qjson.h
  238. qlist.c
  239. qlist.h
  240. qmp-commands.hx
  241. qobject.h
  242. qstring.c
  243. qstring.h
  244. range.h
  245. readline.c
  246. readline.h
  247. README
  248. rules.mak
  249. rwhandler.c
  250. rwhandler.h
  251. s390-dis.c
  252. s390.ld
  253. savevm.c
  254. sh4-dis.c
  255. simpletrace.c
  256. simpletrace.h
  257. softmmu-semi.h
  258. softmmu_defs.h
  259. softmmu_exec.h
  260. softmmu_header.h
  261. softmmu_template.h
  262. sparc-dis.c
  263. sparc.ld
  264. sparc64.ld
  265. spice-qemu-char.c
  266. sysemu.h
  267. targphys.h
  268. tcg-runtime.c
  269. thunk.c
  270. thunk.h
  271. TODO
  272. trace-events
  273. translate-all.c
  274. uboot_image.h
  275. usb-bsd.c
  276. usb-linux.c
  277. usb-stub.c
  278. VERSION
  279. version.rc
  280. vgafont.h
  281. vl.c
  282. x86_64.ld