Re: [PATCH 0/4] mmu_notifier semantic update

From: Jerome Glisse
Date: Tue Aug 29 2017 - 16:16:05 EST


On Tue, Aug 29, 2017 at 04:11:28PM -0400, Jérôme Glisse wrote:
> So we do not want to allow sleep during call to mmu_notifier_invalidate_page()
> but some code do not have surrounding mmu_notifier_invalidate_range_start()/
> mmu_notifier_invalidate_range_end() or mmu_notifier_invalidate_range()
>
> This patch serie just make sure that there is at least a call (outside spinlock
> section) to mmu_notifier_invalidate_range() after mmu_notifier_invalidate_page()
>
> This fix issue with AMD IOMMU v2 while avoiding to introduce issue for others
> user of the mmu_notifier API. For releavent threads see:
>
> https://lkml.kernel.org/r/20170809204333.27485-1-jglisse@xxxxxxxxxx
> https://lkml.kernel.org/r/20170804134928.l4klfcnqatni7vsc@xxxxxxxxxxxxxxxxxx
> https://marc.info/?l=kvm&m=150327081325160&w=2

Please ignore this. Instead plan is to kill invalidate_page() switch
it to invalidate_range() and make sure there is always range_start/
range_end happening around.

Jérôme