memory: fix limiting of translation at a page boundary

Commit 360e607 (address_space_translate: do not cross page boundaries,
2014-01-30) broke MMIO accesses in cases where the section is shorter
than the full register width.  This can happen for example with the
Bochs DISPI registers, which are 16 bits wide but have only a 1-byte
long MemoryRegion (if you write to the "second byte" of the register
your access is discarded; it doesn't write only to half of the register).

Restrict the action of commit 360e607 to direct RAM accesses.  This
is enough for Xen, since MMIO will not go through the mapcache.

Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
1 file changed
tree: 53c42691028566ae1d64a4a911b151d97c55ad35
  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. linux-headers/
  15. linux-user/
  16. net/
  17. pc-bios/
  18. po/
  19. qapi/
  20. qga/
  21. qobject/
  22. qom/
  23. roms/
  24. scripts/
  25. slirp/
  26. stubs/
  27. sysconfigs/
  28. target-alpha/
  29. target-arm/
  30. target-cris/
  31. target-i386/
  32. target-lm32/
  33. target-m68k/
  34. target-microblaze/
  35. target-mips/
  36. target-moxie/
  37. target-openrisc/
  38. target-ppc/
  39. target-s390x/
  40. target-sh4/
  41. target-sparc/
  42. target-unicore32/
  43. target-xtensa/
  44. tcg/
  45. tests/
  46. trace/
  47. ui/
  48. util/
  49. .exrc
  50. .gitignore
  51. .gitmodules
  52. .mailmap
  53. .travis.yml
  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. CODING_STYLE
  68. configure
  69. COPYING
  70. COPYING.LIB
  71. coroutine-gthread.c
  72. coroutine-sigaltstack.c
  73. coroutine-ucontext.c
  74. coroutine-win32.c
  75. cpu-exec.c
  76. cpus.c
  77. cputlb.c
  78. device-hotplug.c
  79. device_tree.c
  80. disas.c
  81. dma-helpers.c
  82. dump.c
  83. exec.c
  84. gdbstub.c
  85. HACKING
  86. hmp-commands.hx
  87. hmp.c
  88. hmp.h
  89. iohandler.c
  90. ioport.c
  91. kvm-all.c
  92. kvm-stub.c
  93. LICENSE
  94. main-loop.c
  95. MAINTAINERS
  96. Makefile
  97. Makefile.objs
  98. Makefile.target
  99. memory.c
  100. memory_mapping.c
  101. migration-exec.c
  102. migration-fd.c
  103. migration-rdma.c
  104. migration-tcp.c
  105. migration-unix.c
  106. migration.c
  107. monitor.c
  108. nbd.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-file.c
  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. spice-qemu-char.c
  146. tcg-runtime.c
  147. tci.c
  148. thread-pool.c
  149. thunk.c
  150. tpm.c
  151. trace-events
  152. translate-all.c
  153. translate-all.h
  154. user-exec.c
  155. VERSION
  156. version.rc
  157. vl.c
  158. vmstate.c
  159. xbzrle.c
  160. xen-all.c
  161. xen-mapcache.c
  162. xen-stub.c