Messages in this thread | | | Subject | Re: [PATCH v3 00/15] KVM: Dynamically size memslot arrays | Date | Fri, 25 Oct 2019 17:30:20 +0100 | From | Marc Zyngier <> |
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On 2019-10-25 00:07, Sean Christopherson wrote: > The end goal of this series is to dynamically size the memslot array > so > that KVM allocates memory based on the number of memslots in use, as > opposed to unconditionally allocating memory for the maximum number > of > memslots. On x86, each memslot consumes 88 bytes, and so with 2 > address > spaces of 512 memslots, each VM consumes ~90k bytes for the memslots. > E.g. given a VM that uses a total of 30 memslots, dynamic sizing > reduces > the memory footprint from 90k to ~2.6k bytes. > > The changes required to support dynamic sizing are relatively small, > e.g. are essentially contained in patches 14/15 and 15/15. Patches > 1-13 > clean up the memslot code, which has gotten quite crusty, especially > __kvm_set_memory_region(). The clean up is likely not strictly > necessary > to switch to dynamic sizing, but I didn't have a remotely reasonable > level of confidence in the correctness of the dynamic sizing without > first > doing the clean up.
I've finally found time to test this on a garden variety of arm64 boxes, and nothing caught fire. It surely must be doing something right!
FWIW:
Tested-by: Marc Zyngier <maz@kernel.org>
M. -- Jazz is not dead. It just smells funny...
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