block: vhdx - change .vhdx_create default block state to ZERO

The VHDX spec specifies that the default new block state is
PAYLOAD_BLOCK_NOT_PRESENT for a dynamic VHDX image, and
PAYLOAD_BLOCK_FULLY_PRESENT for a fixed VHDX image.

However, in order to create space-efficient VHDX images with qemu-img
convert, it is desirable to be able to set has_zero_init to true for
VHDX.

There is currently an option when creating VHDX images, to use block
state ZERO for new blocks.  However, this currently defaults to 'off'.
In order to be able to eventually set has_zero_init to true for VHDX,
this needs to default to 'on'.

This patch changes the default to 'on', and provides some help
information to warn against setting it to 'off' when using qemu-img
convert.

[Max Reitz pointed out that a full stop was missing at the end of the
VHDX_BLOCK_OPT_ZERO option help text.  I have added it.
--Stefan]

Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 85164899eacc86e150c3ceba793cf93b398dedd7.1418018421.git.jcody@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2 files changed
tree: cbaaf5c2ae2e3f541bed8354bc5bd8075ef23ec7
  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. accel.c
  57. aio-posix.c
  58. aio-win32.c
  59. arch_init.c
  60. async.c
  61. balloon.c
  62. block-migration.c
  63. block.c
  64. blockdev-nbd.c
  65. blockdev.c
  66. blockjob.c
  67. bootdevice.c
  68. bt-host.c
  69. bt-vhci.c
  70. Changelog
  71. CODING_STYLE
  72. configure
  73. COPYING
  74. COPYING.LIB
  75. coroutine-gthread.c
  76. coroutine-sigaltstack.c
  77. coroutine-ucontext.c
  78. coroutine-win32.c
  79. cpu-exec.c
  80. cpus.c
  81. cputlb.c
  82. device-hotplug.c
  83. device_tree.c
  84. disas.c
  85. dma-helpers.c
  86. dump.c
  87. exec.c
  88. gdbstub.c
  89. HACKING
  90. hmp-commands.hx
  91. hmp.c
  92. hmp.h
  93. iohandler.c
  94. ioport.c
  95. iothread.c
  96. kvm-all.c
  97. kvm-stub.c
  98. LICENSE
  99. main-loop.c
  100. MAINTAINERS
  101. Makefile
  102. Makefile.objs
  103. Makefile.target
  104. memory.c
  105. memory_mapping.c
  106. migration-exec.c
  107. migration-fd.c
  108. migration-rdma.c
  109. migration-tcp.c
  110. migration-unix.c
  111. migration.c
  112. module-common.c
  113. monitor.c
  114. nbd.c
  115. numa.c
  116. os-posix.c
  117. os-win32.c
  118. page_cache.c
  119. qapi-schema.json
  120. qdev-monitor.c
  121. qdict-test-data.txt
  122. qemu-bridge-helper.c
  123. qemu-char.c
  124. qemu-coroutine-io.c
  125. qemu-coroutine-lock.c
  126. qemu-coroutine-sleep.c
  127. qemu-coroutine.c
  128. qemu-doc.texi
  129. qemu-file-stdio.c
  130. qemu-file-unix.c
  131. qemu-file.c
  132. qemu-img-cmds.hx
  133. qemu-img.c
  134. qemu-img.texi
  135. qemu-io-cmds.c
  136. qemu-io.c
  137. qemu-log.c
  138. qemu-nbd.c
  139. qemu-nbd.texi
  140. qemu-options-wrapper.h
  141. qemu-options.h
  142. qemu-options.hx
  143. qemu-seccomp.c
  144. qemu-tech.texi
  145. qemu-timer.c
  146. qemu.nsi
  147. qemu.sasl
  148. qmp-commands.hx
  149. qmp.c
  150. qtest.c
  151. README
  152. rules.mak
  153. savevm.c
  154. softmmu_template.h
  155. spice-qemu-char.c
  156. tcg-runtime.c
  157. tci.c
  158. thread-pool.c
  159. thunk.c
  160. tpm.c
  161. trace-events
  162. translate-all.c
  163. translate-all.h
  164. user-exec.c
  165. VERSION
  166. version.rc
  167. vl.c
  168. vmstate.c
  169. xbzrle.c
  170. xen-common-stub.c
  171. xen-common.c
  172. xen-hvm-stub.c
  173. xen-hvm.c
  174. xen-mapcache.c