Re: [RFC PATCH v2 5/5] KVM: Unmap pages only when it's indeed protected for NUMA migration

From: Yan Zhao
Date: Wed Aug 16 2023 - 03:46:09 EST


On Wed, Aug 16, 2023 at 03:29:22PM +0800, bibo mao wrote:
> > Flush must be done before kvm->mmu_lock is unlocked, otherwise,
> > confusion will be caused when multiple threads trying to update the
> > secondary MMU.
> Since tlb flush is delayed after all pte entries are cleared, and currently
> there is no tlb flush range supported for secondary mmu. I do know why there
> is confusion before or after kvm->mmu_lock.

Oh, do you mean only do kvm_unmap_gfn_range() in .invalidate_range_end()?
Then check if PROT_NONE is set in primary MMU before unmap?
Looks like a good idea, I need to check if it's feasible.
Thanks!