blockdev: enable discard by default

Because discard is now a host parameter, we can always fake it as enabled
in the guest.  This is an extension of the current choice to ignore
"not supported" errors from the host when discard_granularity is set
to nonzero.

The default granularity is set to the logical block size or 4k, whichever
is largest, because cluster sizes below 4k are rarely used and 4K is a
typical block size for files.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
3 files changed
tree: d1ae0848fbdfc0ef88ac9d87abc23171fde3d6cb
  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. ldscripts/
  14. libcacard/
  15. linux-headers/
  16. linux-user/
  17. net/
  18. pc-bios/
  19. po/
  20. qapi/
  21. qga/
  22. QMP/
  23. qobject/
  24. qom/
  25. roms/
  26. scripts/
  27. slirp/
  28. stubs/
  29. sysconfigs/
  30. target-alpha/
  31. target-arm/
  32. target-cris/
  33. target-i386/
  34. target-lm32/
  35. target-m68k/
  36. target-microblaze/
  37. target-mips/
  38. target-openrisc/
  39. target-ppc/
  40. target-s390x/
  41. target-sh4/
  42. target-sparc/
  43. target-unicore32/
  44. target-xtensa/
  45. tcg/
  46. tests/
  47. trace/
  48. ui/
  49. util/
  50. .exrc
  51. .gitignore
  52. .gitmodules
  53. .mailmap
  54. aio-posix.c
  55. aio-win32.c
  56. arch_init.c
  57. async.c
  58. balloon.c
  59. block-migration.c
  60. block.c
  61. blockdev-nbd.c
  62. blockdev.c
  63. blockjob.c
  64. bt-host.c
  65. bt-vhci.c
  66. Changelog
  67. cmd.c
  68. cmd.h
  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_tree.c
  81. disas.c
  82. dma-helpers.c
  83. dump-stub.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. kvm-all.c
  94. kvm-stub.c
  95. LICENSE
  96. main-loop.c
  97. MAINTAINERS
  98. Makefile
  99. Makefile.objs
  100. Makefile.target
  101. memory.c
  102. memory_mapping-stub.c
  103. memory_mapping.c
  104. migration-exec.c
  105. migration-fd.c
  106. migration-tcp.c
  107. migration-unix.c
  108. migration.c
  109. monitor.c
  110. nbd.c
  111. os-posix.c
  112. os-win32.c
  113. page_cache.c
  114. qapi-schema-test.json
  115. qapi-schema.json
  116. qdict-test-data.txt
  117. qemu-bridge-helper.c
  118. qemu-char.c
  119. qemu-coroutine-io.c
  120. qemu-coroutine-lock.c
  121. qemu-coroutine-sleep.c
  122. qemu-coroutine.c
  123. qemu-doc.texi
  124. qemu-img-cmds.hx
  125. qemu-img.c
  126. qemu-img.texi
  127. qemu-io.c
  128. qemu-log.c
  129. qemu-nbd.c
  130. qemu-nbd.texi
  131. qemu-options-wrapper.h
  132. qemu-options.h
  133. qemu-options.hx
  134. qemu-seccomp.c
  135. qemu-tech.texi
  136. qemu-timer.c
  137. qemu.sasl
  138. qmp-commands.hx
  139. qmp.c
  140. qtest.c
  141. readline.c
  142. README
  143. rules.mak
  144. savevm.c
  145. spice-qemu-char.c
  146. tcg-runtime.c
  147. tci.c
  148. thread-pool.c
  149. thunk.c
  150. trace-events
  151. translate-all.c
  152. translate-all.h
  153. user-exec.c
  154. VERSION
  155. version.rc
  156. vl.c
  157. xbzrle.c
  158. xen-all.c
  159. xen-mapcache.c
  160. xen-stub.c