On 22/10/19 02:35, 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 12/13 and 13/13. Patches 1-11 > clean up the memslot code, which has gotten quite crusy, 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. > > Testing, especially non-x86 platforms, would be greatly appreciated. The > non-x86 changes are for all intents and purposes untested, e.g. I compile > tested pieces of the code by copying them into x86, but that's it. In > theory, the vast majority of the functional changes are arch agnostic, in > theory... > > v2: > - Split "Drop kvm_arch_create_memslot()" into three patches to move > minor functional changes to standalone patches [Janosch]. > - Rebase to latest kvm/queue (f0574a1cea5b, "KVM: x86: fix ...") > - Collect an Acked-by and a Reviewed-by I only have some cosmetic changes on patches 14-15. Let's wait for testing results. Paolo _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
