qapi: Introduce add-fd, remove-fd, query-fdsets

This patch adds support that enables passing of file descriptors
to the QEMU monitor where they will be stored in specified file
descriptor sets.

A file descriptor set can be used by a client like libvirt to
store file descriptors for the same file.  This allows the
client to open a file with different access modes (O_RDWR,
O_WRONLY, O_RDONLY) and add/remove the passed fds to/from an fd
set as needed.  This will allow QEMU to (in a later patch in this
series) "open" and "reopen" the same file by dup()ing the fd in
the fd set that corresponds to the file, where the fd has the
matching access mode flag that QEMU requests.

The new QMP commands are:
  add-fd: Add a file descriptor to an fd set
  remove-fd: Remove a file descriptor from an fd set
  query-fdsets: Return information describing all fd sets

Note: These commands are not compatible with the existing getfd
and closefd QMP commands.

Signed-off-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
3 files changed
tree: 81763c5e59a44cfa5fe003747afd52b72738f651
  1. audio/
  2. block/
  3. bsd-user/
  4. default-configs/
  5. docs/
  6. fpu/
  7. fsdev/
  8. gdb-xml/
  9. hw/
  10. include/
  11. libcacard/
  12. linux-headers/
  13. linux-user/
  14. net/
  15. pc-bios/
  16. qapi/
  17. qga/
  18. QMP/
  19. qom/
  20. roms/
  21. scripts/
  22. slirp/
  23. sysconfigs/
  24. target-alpha/
  25. target-arm/
  26. target-cris/
  27. target-i386/
  28. target-lm32/
  29. target-m68k/
  30. target-microblaze/
  31. target-mips/
  32. target-openrisc/
  33. target-ppc/
  34. target-s390x/
  35. target-sh4/
  36. target-sparc/
  37. target-unicore32/
  38. target-xtensa/
  39. tcg/
  40. tests/
  41. trace/
  42. ui/
  43. .gitignore
  44. .gitmodules
  45. .mailmap
  46. a.out.h
  47. acl.c
  48. acl.h
  49. aes.c
  50. aes.h
  51. aio.c
  52. alpha-dis.c
  53. alpha.ld
  54. arch_init.c
  55. arch_init.h
  56. arm-dis.c
  57. arm.ld
  58. async.c
  59. balloon.c
  60. balloon.h
  61. bitmap.c
  62. bitmap.h
  63. bitops.c
  64. bitops.h
  65. block-migration.c
  66. block-migration.h
  67. block.c
  68. block.h
  69. block_int.h
  70. blockdev.c
  71. blockdev.h
  72. bswap.h
  73. bt-host.c
  74. bt-host.h
  75. bt-vhci.c
  76. buffered_file.c
  77. buffered_file.h
  78. cache-utils.c
  79. cache-utils.h
  80. Changelog
  81. cmd.c
  82. cmd.h
  83. CODING_STYLE
  84. compatfd.c
  85. compatfd.h
  86. compiler.h
  87. config.h
  88. configure
  89. console.c
  90. console.h
  91. COPYING
  92. COPYING.LIB
  93. coroutine-gthread.c
  94. coroutine-sigaltstack.c
  95. coroutine-ucontext.c
  96. coroutine-win32.c
  97. cpu-all.h
  98. cpu-common.h
  99. cpu-defs.h
  100. cpu-exec.c
  101. cpus.c
  102. cpus.h
  103. cputlb.c
  104. cputlb.h
  105. cris-dis.c
  106. cursor.c
  107. cursor_hidden.xpm
  108. cursor_left_ptr.xpm
  109. cutils.c
  110. def-helper.h
  111. device_tree.c
  112. device_tree.h
  113. dis-asm.h
  114. disas.c
  115. disas.h
  116. dma-helpers.c
  117. dma.h
  118. dump-stub.c
  119. dump.c
  120. dump.h
  121. dyngen-exec.h
  122. elf.h
  123. envlist.c
  124. envlist.h
  125. error.c
  126. error.h
  127. event_notifier.c
  128. event_notifier.h
  129. exec-all.h
  130. exec-memory.h
  131. exec-obsolete.h
  132. exec.c
  133. gdbstub.c
  134. gdbstub.h
  135. gen-icount.h
  136. HACKING
  137. hmp-commands.hx
  138. hmp.c
  139. hmp.h
  140. host-utils.c
  141. host-utils.h
  142. hppa-dis.c
  143. hppa.ld
  144. i386-dis.c
  145. i386.ld
  146. ia64-dis.c
  147. ia64.ld
  148. input.c
  149. int128.h
  150. iohandler.c
  151. ioport.c
  152. ioport.h
  153. iorange.h
  154. iov.c
  155. iov.h
  156. json-lexer.c
  157. json-lexer.h
  158. json-parser.c
  159. json-parser.h
  160. json-streamer.c
  161. json-streamer.h
  162. kvm-all.c
  163. kvm-stub.c
  164. kvm.h
  165. libfdt_env.h
  166. LICENSE
  167. linux-aio.c
  168. lm32-dis.c
  169. m68k-dis.c
  170. m68k.ld
  171. main-loop.c
  172. main-loop.h
  173. MAINTAINERS
  174. Makefile
  175. Makefile.dis
  176. Makefile.hw
  177. Makefile.objs
  178. Makefile.target
  179. Makefile.user
  180. memory.c
  181. memory.h
  182. memory_mapping-stub.c
  183. memory_mapping.c
  184. memory_mapping.h
  185. microblaze-dis.c
  186. migration-exec.c
  187. migration-fd.c
  188. migration-tcp.c
  189. migration-unix.c
  190. migration.c
  191. migration.h
  192. mips-dis.c
  193. mips.ld
  194. module.c
  195. module.h
  196. monitor.c
  197. monitor.h
  198. nbd.c
  199. nbd.h
  200. net.c
  201. net.h
  202. notify.c
  203. notify.h
  204. os-posix.c
  205. os-win32.c
  206. osdep.c
  207. osdep.h
  208. oslib-posix.c
  209. oslib-win32.c
  210. page_cache.c
  211. path.c
  212. pci-ids.txt
  213. pflib.c
  214. pflib.h
  215. poison.h
  216. posix-aio-compat.c
  217. ppc-dis.c
  218. ppc.ld
  219. ppc64.ld
  220. qapi-schema-guest.json
  221. qapi-schema-test.json
  222. qapi-schema.json
  223. qbool.c
  224. qbool.h
  225. qdict-test-data.txt
  226. qdict.c
  227. qdict.h
  228. qemu-aio.h
  229. qemu-barrier.h
  230. qemu-bridge-helper.c
  231. qemu-char.c
  232. qemu-char.h
  233. qemu-common.h
  234. qemu-config.c
  235. qemu-config.h
  236. qemu-coroutine-int.h
  237. qemu-coroutine-io.c
  238. qemu-coroutine-lock.c
  239. qemu-coroutine-sleep.c
  240. qemu-coroutine.c
  241. qemu-coroutine.h
  242. qemu-doc.texi
  243. qemu-error.c
  244. qemu-error.h
  245. qemu-file.h
  246. qemu-ga.c
  247. qemu-img-cmds.hx
  248. qemu-img.c
  249. qemu-img.texi
  250. qemu-io.c
  251. qemu-lock.h
  252. qemu-log.c
  253. qemu-log.h
  254. qemu-nbd.c
  255. qemu-nbd.texi
  256. qemu-objects.h
  257. qemu-option-internal.h
  258. qemu-option.c
  259. qemu-option.h
  260. qemu-options-wrapper.h
  261. qemu-options.h
  262. qemu-options.hx
  263. qemu-os-posix.h
  264. qemu-os-win32.h
  265. qemu-progress.c
  266. qemu-queue.h
  267. qemu-sockets.c
  268. qemu-tech.texi
  269. qemu-thread-posix.c
  270. qemu-thread-posix.h
  271. qemu-thread-win32.c
  272. qemu-thread-win32.h
  273. qemu-thread.h
  274. qemu-timer-common.c
  275. qemu-timer.c
  276. qemu-timer.h
  277. qemu-tls.h
  278. qemu-tool.c
  279. qemu-user.c
  280. qemu-x509.h
  281. qemu-xattr.h
  282. qemu.sasl
  283. qemu_socket.h
  284. qerror.c
  285. qerror.h
  286. qfloat.c
  287. qfloat.h
  288. qint.c
  289. qint.h
  290. qjson.c
  291. qjson.h
  292. qlist.c
  293. qlist.h
  294. qmp-commands.hx
  295. qmp.c
  296. qobject.h
  297. qstring.c
  298. qstring.h
  299. qtest.c
  300. qtest.h
  301. range.h
  302. readline.c
  303. readline.h
  304. README
  305. rules.mak
  306. s390-dis.c
  307. s390.ld
  308. savevm.c
  309. sh4-dis.c
  310. softmmu-semi.h
  311. softmmu_defs.h
  312. softmmu_exec.h
  313. softmmu_header.h
  314. softmmu_template.h
  315. sparc-dis.c
  316. sparc.ld
  317. sparc64.ld
  318. spice-qemu-char.c
  319. sysemu.h
  320. targphys.h
  321. tcg-runtime.c
  322. tci-dis.c
  323. tci.c
  324. thunk.c
  325. thunk.h
  326. TODO
  327. trace-events
  328. translate-all.c
  329. uboot_image.h
  330. user-exec.c
  331. VERSION
  332. version.rc
  333. vgafont.h
  334. vl.c
  335. vmstate.h
  336. x86_64.ld
  337. xen-all.c
  338. xen-mapcache.c
  339. xen-mapcache.h
  340. xen-stub.c