[PATCH v0 0/4] backends/hostmem: add an ability to specify prealloc timeout

[Daniil Tatianin]

This series introduces new qemu_prealloc_mem_with_timeout() api,
which allows limiting the maximum amount of time to be spent on memory
preallocation. It also adds prealloc statistics collection that is
exposed via an optional timeout handler.

This new api is then utilized by hostmem for guest RAM preallocation
controlled via new object properties called 'prealloc-timeout' and
'prealloc-timeout-fatal'.

This is useful for limiting VM startup time on systems with
unpredictable page allocation delays due to memory fragmentation or the
backing storage. The timeout can be configured to either simply emit a
warning and continue VM startup without having preallocated the entire
guest RAM or just abort startup entirely if that is not acceptable for
a specific use case.

Daniil Tatianin (4):
  oslib: introduce new qemu_prealloc_mem_with_timeout() api
  backends/hostmem: move memory region preallocation logic into a helper
  backends/hostmem: add an ability to specify prealloc timeout
  backends/hostmem: add an ability to make prealloc timeout fatal

 backends/hostmem.c       | 112 +++++++++++++++++++++++++++++++-------
 include/qemu/osdep.h     |  19 +++++++
 include/sysemu/hostmem.h |   3 ++
 qapi/qom.json            |   8 +++
 util/oslib-posix.c       | 114 +++++++++++++++++++++++++++++++++++----
 util/oslib-win32.c       |   9 ++++
 6 files changed, 238 insertions(+), 27 deletions(-)

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2.25.1