memory: API to allocate resizeable RAM MR

Add API to allocate resizeable RAM MR.

This looks just like regular RAM generally, but
has a special property that only a portion of it
(used_length) is actually used, and migrated.

This used_length size can change across reboots.

Follow up patches will change used_length for such blocks at migration,
making it easier to extend devices using such RAM (notably ACPI,
but in the future thinkably other ROMs) without breaking migration
compatibility or wasting ROM (guest) memory.

Device is notified on resize, so it can adjust if necessary.

Note: nothing prevents making all RAM resizeable in this way.
However, reviewers felt that only enabling this selectively will
make some class of errors easier to detect.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2 files changed
tree: 753ad52ec84d825b4d5e4c878ac99f62e032226b
  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. 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-moxie/
  39. target-openrisc/
  40. target-ppc/
  41. target-s390x/
  42. target-sh4/
  43. target-sparc/
  44. target-tricore/
  45. target-unicore32/
  46. target-xtensa/
  47. tcg/
  48. tests/
  49. trace/
  50. ui/
  51. util/
  52. .exrc
  53. .gitignore
  54. .gitmodules
  55. .mailmap
  56. .travis.yml
  57. accel.c
  58. aio-posix.c
  59. aio-win32.c
  60. arch_init.c
  61. async.c
  62. balloon.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. module-common.c
  107. monitor.c
  108. nbd.c
  109. numa.c
  110. os-posix.c
  111. os-win32.c
  112. page_cache.c
  113. qapi-schema.json
  114. qdev-monitor.c
  115. qdict-test-data.txt
  116. qemu-bridge-helper.c
  117. qemu-char.c
  118. qemu-coroutine-io.c
  119. qemu-coroutine-lock.c
  120. qemu-coroutine-sleep.c
  121. qemu-coroutine.c
  122. qemu-doc.texi
  123. qemu-img-cmds.hx
  124. qemu-img.c
  125. qemu-img.texi
  126. qemu-io-cmds.c
  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.nsi
  138. qemu.sasl
  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