async: aio_context_new(): Handle event_notifier_init failure

On a system with a low limit of open files the initialization
of the event notifier could fail and QEMU exits without printing any
error information to the user.

The problem can be easily reproduced by enforcing a low limit of open
files and start QEMU with enough I/O threads to hit this limit.

The same problem raises, without the creation of I/O threads, while
QEMU initializes the main event loop by enforcing an even lower limit of
open files.

This commit adds an error message on failure:

 # qemu [...] -object iothread,id=iothread0 -object iothread,id=iothread1
 qemu: Failed to initialize event notifier: Too many open files in system

Signed-off-by: Chrysostomos Nanakos <cnanakos@grnet.gr>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
12 files changed
tree: b0bbeff681f1f2910502ecf132cfb96258a350ad
  1. audio/
  2. backends/
  3. block/
  4. bsd-user/
  5. default-configs/
  6. disas/
  7. docs/
  8. fpu/
  9. fsdev/
  10. gdb-xml/
  11. hw/
  12. include/
  13. libcacard/
  14. libdecnumber/
  15. linux-headers/
  16. linux-user/
  17. net/
  18. pc-bios/
  19. po/
  20. qapi/
  21. qga/
  22. qobject/
  23. qom/
  24. roms/
  25. scripts/
  26. slirp/
  27. stubs/
  28. sysconfigs/
  29. target-alpha/
  30. target-arm/
  31. target-cris/
  32. target-i386/
  33. target-lm32/
  34. target-m68k/
  35. target-microblaze/
  36. target-mips/
  37. target-moxie/
  38. target-openrisc/
  39. target-ppc/
  40. target-s390x/
  41. target-sh4/
  42. target-sparc/
  43. target-tricore/
  44. target-unicore32/
  45. target-xtensa/
  46. tcg/
  47. tests/
  48. trace/
  49. ui/
  50. util/
  51. .exrc
  52. .gitignore
  53. .gitmodules
  54. .mailmap
  55. .travis.yml
  56. aio-posix.c
  57. aio-win32.c
  58. arch_init.c
  59. async.c
  60. balloon.c
  61. block-migration.c
  62. block.c
  63. blockdev-nbd.c
  64. blockdev.c
  65. blockjob.c
  66. bt-host.c
  67. bt-vhci.c
  68. Changelog
  69. CODING_STYLE
  70. configure
  71. COPYING
  72. COPYING.LIB
  73. coroutine-gthread.c
  74. coroutine-sigaltstack.c
  75. coroutine-ucontext.c
  76. coroutine-win32.c
  77. cpu-exec.c
  78. cpus.c
  79. cputlb.c
  80. device-hotplug.c
  81. device_tree.c
  82. disas.c
  83. dma-helpers.c
  84. dump.c
  85. exec.c
  86. gdbstub.c
  87. HACKING
  88. hmp-commands.hx
  89. hmp.c
  90. hmp.h
  91. iohandler.c
  92. ioport.c
  93. iothread.c
  94. kvm-all.c
  95. kvm-stub.c
  96. LICENSE
  97. main-loop.c
  98. MAINTAINERS
  99. Makefile
  100. Makefile.objs
  101. Makefile.target
  102. memory.c
  103. memory_mapping.c
  104. migration-exec.c
  105. migration-fd.c
  106. migration-rdma.c
  107. migration-tcp.c
  108. migration-unix.c
  109. migration.c
  110. module-common.c
  111. monitor.c
  112. nbd.c
  113. numa.c
  114. os-posix.c
  115. os-win32.c
  116. page_cache.c
  117. qapi-schema.json
  118. qdev-monitor.c
  119. qdict-test-data.txt
  120. qemu-bridge-helper.c
  121. qemu-char.c
  122. qemu-coroutine-io.c
  123. qemu-coroutine-lock.c
  124. qemu-coroutine-sleep.c
  125. qemu-coroutine.c
  126. qemu-doc.texi
  127. qemu-file.c
  128. qemu-img-cmds.hx
  129. qemu-img.c
  130. qemu-img.texi
  131. qemu-io-cmds.c
  132. qemu-io.c
  133. qemu-log.c
  134. qemu-nbd.c
  135. qemu-nbd.texi
  136. qemu-options-wrapper.h
  137. qemu-options.h
  138. qemu-options.hx
  139. qemu-seccomp.c
  140. qemu-tech.texi
  141. qemu-timer.c
  142. qemu.nsi
  143. qemu.sasl
  144. qmp-commands.hx
  145. qmp.c
  146. qtest.c
  147. README
  148. rules.mak
  149. savevm.c
  150. softmmu_template.h
  151. spice-qemu-char.c
  152. tcg-runtime.c
  153. tci.c
  154. thread-pool.c
  155. thunk.c
  156. tpm.c
  157. trace-events
  158. translate-all.c
  159. translate-all.h
  160. user-exec.c
  161. VERSION
  162. version.rc
  163. vl.c
  164. vmstate.c
  165. xbzrle.c
  166. xen-common-stub.c
  167. xen-common.c
  168. xen-hvm-stub.c
  169. xen-hvm.c
  170. xen-mapcache.c