Re: [PATCH v10 10/10] vfio: Don't issue full 2^64 unmap

[Alex Williamson]

On Mon, 2 Nov 2020 18:44:11 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> On 02/11/20 18:37, Alex Williamson wrote:
> > I think we still have the issue at the vfio ioctl which takes __u64 iova
> > and size parameters, in bytes.  Therefore we cannot unmap an entire
> > 64-bit address space with a single ioctl call.  We'd need to make use
> > of a flag to modify the ioctl behavior to work terms of some page size
> > to achieve this, for example if iova and size were in terms of 4K
> > pages, we wouldn't have this issue.  Thanks,  
> 
> What happens to the last page if size is unaligned (e.g. iova==0, size==
> 2^64-1)?

Both args are currently required to be aligned to the minimum IOMMU
page size.  Thanks,

Alex