Tags: openSUSE/qemu
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[RFC] memory: Add a new argument to indicate the request attribute in…
… RamDismcardManager helpers
For each ram_discard_manager helper, add a new argument 'is_private' to
indicate the request attribute. If is_private is true, the operation
targets the private range in the section. For example,
replay_populate(true) will replay the populate operation on private part
in the MemoryRegionSection, while replay_popuate(false) will replay
population on shared part.
This helps to distinguish between the states of private/shared and
discarded/populated. It is essential for guest_memfd_manager which uses
RamDiscardManager interface but can't treat private memory as discarded
memory. This is because it does not align with the expectation of
current RamDiscardManager users (e.g. live migration), who expect that
discarded memory is hot-removed and can be skipped when processing guest
memory. Treating private memory as discarded won't work in the future if
live migration needs to handle private memory. For example, live
migration needs to migrate private memory.
The user of the helper needs to figure out which attribute to
manipulate. For legacy VM case, use is_private=true by default. Private
attribute is only valid in a guest_memfd based VM.
Opportunistically rename the guest_memfd_for_each_{discarded,
populated}_section() to guest_memfd_for_each_{private, shared)_section()
to distinguish between private/shared and discarded/populated at the
same time.
Signed-off-by: Chenyi Qiang <[email protected]>
memory: Add a new argument to indicate the request attribute in RamDi…
…smcardManager helpers
For each ram_discard_manager helper, add a new argument 'is_private' to
indicate the request attribute. If is_private is true, the operation
targets the private range in the section. For example,
replay_populate(true) will replay the populate operation on private part
in the MemoryRegionSection, while replay_popuate(false) will replay
population on shared part.
This helps to distinguish between the states of private/shared and
discarded/populated. It is essential for guest_memfd_manager which uses
RamDiscardManager interface but can't treat private memory as discarded
memory. This is because it does not align with the expectation of
current RamDiscardManager users (e.g. live migration), who expect that
discarded memory is hot-removed and can be skipped when processing guest
memory. Treating private memory as discarded won't work in the future if
live migration needs to handle private memory. For example, live
migration needs to migrate private memory.
The user of the helper needs to figure out which attribute to
manipulate. For legacy VM case, use is_private=true by default. Private
attribute is only valid in a guest_memfd based VM.
Opportunistically rename the guest_memfd_for_each_{discarded,
populated}_section() to guest_memfd_for_each_{private, shared)_section()
to distinguish between private/shared and discarded/populated at the
same time.
Signed-off-by: Chenyi Qiang <[email protected]>
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