Re: [RFC PATCH 3/3] KVM: x86/mmu: skip zap maybe-dma-pinned pages for NUMA migration

From: Jason Gunthorpe
Date: Wed Aug 09 2023 - 07:59:26 EST


On Wed, Aug 09, 2023 at 08:11:17AM +0800, Yan Zhao wrote:

> > Can we just tell userspace to mbind() the pinned region to explicitly exclude the
> > VMA(s) from NUMA balancing?

> For VMs with VFIO mdev mediated devices, the VMAs to be pinned are
> dynamic, I think it's hard to mbind() in advance.

It is hard to view the mediated devices path as a performance path
that deserves this kind of intervention :\

Jason