memory: prepare for multiple bits in the dirty log mask

When the dirty log mask will also cover other bits than DIRTY_MEMORY_VGA,
some listeners may be interested in the overall zero/non-zero value of
the dirty log mask; others may be interested in the value of single bits.

For this reason, always call log_start/log_stop if bits have respectively
appeared or disappeared, and pass the old and new values of the dirty log
mask so that listeners can distinguish the kinds of change.

For example, KVM checks if dirty logging used to be completely disabled
(in log_start) or is now completely disabled (in log_stop).  On the
other hand, Xen has to check manually if DIRTY_MEMORY_VGA changed,
since that is the only bit it cares about.

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
5 files changed
tree: 0abf5034bdbb2f6595442684020f5d030a844463
  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. migration/
  18. net/
  19. pc-bios/
  20. po/
  21. qapi/
  22. qga/
  23. qobject/
  24. qom/
  25. roms/
  26. scripts/
  27. slirp/
  28. stubs/
  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.c
  63. blockdev-nbd.c
  64. blockdev.c
  65. blockjob.c
  66. bootdevice.c
  67. bt-host.c
  68. bt-vhci.c
  69. Changelog
  70. CODING_STYLE
  71. configure
  72. COPYING
  73. COPYING.LIB
  74. coroutine-gthread.c
  75. coroutine-sigaltstack.c
  76. coroutine-ucontext.c
  77. coroutine-win32.c
  78. cpu-exec.c
  79. cpus.c
  80. cputlb.c
  81. device-hotplug.c
  82. device_tree.c
  83. disas.c
  84. dma-helpers.c
  85. dump.c
  86. exec.c
  87. gdbstub.c
  88. HACKING
  89. hmp-commands.hx
  90. hmp.c
  91. hmp.h
  92. iohandler.c
  93. ioport.c
  94. iothread.c
  95. kvm-all.c
  96. kvm-stub.c
  97. LICENSE
  98. main-loop.c
  99. MAINTAINERS
  100. Makefile
  101. Makefile.objs
  102. Makefile.target
  103. memory.c
  104. memory_mapping.c
  105. module-common.c
  106. monitor.c
  107. nbd.c
  108. numa.c
  109. os-posix.c
  110. os-win32.c
  111. page_cache.c
  112. qapi-schema.json
  113. qdev-monitor.c
  114. qdict-test-data.txt
  115. qemu-bridge-helper.c
  116. qemu-char.c
  117. qemu-coroutine-io.c
  118. qemu-coroutine-lock.c
  119. qemu-coroutine-sleep.c
  120. qemu-coroutine.c
  121. qemu-doc.texi
  122. qemu-img-cmds.hx
  123. qemu-img.c
  124. qemu-img.texi
  125. qemu-io-cmds.c
  126. qemu-io.c
  127. qemu-log.c
  128. qemu-nbd.c
  129. qemu-nbd.texi
  130. qemu-options-wrapper.h
  131. qemu-options.h
  132. qemu-options.hx
  133. qemu-seccomp.c
  134. qemu-tech.texi
  135. qemu-timer.c
  136. qemu.nsi
  137. qemu.sasl
  138. qjson.c
  139. qmp-commands.hx
  140. qmp.c
  141. qtest.c
  142. README
  143. rules.mak
  144. savevm.c
  145. softmmu_template.h
  146. spice-qemu-char.c
  147. tcg-runtime.c
  148. tci.c
  149. thread-pool.c
  150. thunk.c
  151. tpm.c
  152. trace-events
  153. translate-all.c
  154. translate-all.h
  155. user-exec.c
  156. VERSION
  157. version.rc
  158. vl.c
  159. xen-common-stub.c
  160. xen-common.c
  161. xen-hvm-stub.c
  162. xen-hvm.c
  163. xen-mapcache.c