Re: [PATCH v4 4/7] vfio: ap: register IOMMU VFIO notifier
From: Halil Pasic
Date: Thu Feb 28 2019 - 11:55:27 EST
On Thu, 28 Feb 2019 09:48:39 +0100
Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote:
> On 28/02/2019 09:23, Christian Borntraeger wrote:
> > On 22.02.2019 16:29, Pierre Morel wrote:
> >> To be able to use the VFIO interface to facilitate the
> >> mediated device memory pining/unpining we need to register
> >> a notifier for IOMMU.
> > You might want to add that while we start to pin one guest page for the
> > interrupt indicator byte in the next patch, this is still ok with ballooning
> > as this page will never be used by the guest virtio-balloon driver. So the
> > pinned page will never be freed. And even a broken guest does so, that would
> > not impact the host as the original page is still in control by vfio.
> Thanks, I ll do.
I recall a comment in qemu that says vfio-ap does not pin any pages.
That one needs to be fixed up as well.