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qemu / qemu / eaad0fe26050c227dc5dad63205835bac4912a51
commiteaad0fe26050c227dc5dad63205835bac4912a51[log] [tgz]
authorStefan Hajnoczi <stefanha@redhat.com>Mon Dec 04 11:42:56 2023 -0500
committerKevin Wolf <kwolf@redhat.com>Thu Dec 21 22:49:27 2023 +0100
tree6c954c0f7d9cebf9ee228a68b281483a9d4e9fe2
parentbb6e2511eb48539b7dcbcb5f47772e156b9c45d1 [diff]
scsi: only access SCSIDevice->requests from one thread

Stop depending on the AioContext lock and instead access
SCSIDevice->requests from only one thread at a time:
- When the VM is running only the BlockBackend's AioContext may access
  the requests list.
- When the VM is stopped only the main loop may access the requests
  list.

These constraints protect the requests list without the need for locking
in the I/O code path.

Note that multiple IOThreads are not supported yet because the code
assumes all SCSIRequests are executed from a single AioContext. Leave
that as future work.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20231204164259.1515217-2-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2 files changed
tree: 6c954c0f7d9cebf9ee228a68b281483a9d4e9fe2
  1. .github/
  2. .gitlab/
  3. .gitlab-ci.d/
  4. accel/
  5. audio/
  6. authz/
  7. backends/
  8. block/
  9. bsd-user/
  10. chardev/
  11. common-user/
  12. configs/
  13. contrib/
  14. crypto/
  15. disas/
  16. docs/
  17. dump/
  18. ebpf/
  19. fpu/
  20. fsdev/
  21. gdb-xml/
  22. gdbstub/
  23. host/
  24. hw/
  25. include/
  26. io/
  27. libdecnumber/
  28. linux-headers/
  29. linux-user/
  30. migration/
  31. monitor/
  32. nbd/
  33. net/
  34. pc-bios/
  35. plugins/
  36. po/
  37. python/
  38. qapi/
  39. qga/
  40. qobject/
  41. qom/
  42. replay/
  43. roms/
  44. scripts/
  45. scsi/
  46. semihosting/
  47. stats/
  48. storage-daemon/
  49. stubs/
  50. subprojects/
  51. system/
  52. target/
  53. tcg/
  54. tests/
  55. tools/
  56. trace/
  57. ui/
  58. util/
  59. .dir-locals.el
  60. .editorconfig
  61. .exrc
  62. .gdbinit
  63. .git-blame-ignore-revs
  64. .gitattributes
  65. .gitignore
  66. .gitlab-ci.yml
  67. .gitmodules
  68. .gitpublish
  69. .mailmap
  70. .patchew.yml
  71. .readthedocs.yml
  72. .travis.yml
  73. block.c
  74. blockdev-nbd.c
  75. blockdev.c
  76. blockjob.c
  77. configure
  78. COPYING
  79. COPYING.LIB
  80. cpu-common.c
  81. cpu-target.c
  82. event-loop-base.c
  83. gitdm.config
  84. hmp-commands-info.hx
  85. hmp-commands.hx
  86. iothread.c
  87. job-qmp.c
  88. job.c
  89. Kconfig
  90. Kconfig.host
  91. LICENSE
  92. MAINTAINERS
  93. Makefile
  94. memory_ldst.c.inc
  95. meson.build
  96. meson_options.txt
  97. module-common.c
  98. os-posix.c
  99. os-win32.c
  100. page-vary-common.c
  101. page-vary-target.c
  102. pythondeps.toml
  103. qemu-bridge-helper.c
  104. qemu-edid.c
  105. qemu-img-cmds.hx
  106. qemu-img.c
  107. qemu-io-cmds.c
  108. qemu-io.c
  109. qemu-keymap.c
  110. qemu-nbd.c
  111. qemu-options.hx
  112. qemu.nsi
  113. qemu.sasl
  114. README.rst
  115. replication.c
  116. trace-events
  117. VERSION
  118. version.rc