Re: [PATCH 0/2] KVM: MMU: support VMAs that got remap_pfn_range-ed

From: Paolo Bonzini
Date: Tue Jul 05 2016 - 08:18:38 EST




On 05/07/2016 07:41, Neo Jia wrote:
> On Thu, Jun 30, 2016 at 03:01:49PM +0200, Paolo Bonzini wrote:
>> The vGPU folks would like to trap the first access to a BAR by setting
>> vm_ops on the VMAs produced by mmap-ing a VFIO device. The fault handler
>> then can use remap_pfn_range to place some non-reserved pages in the VMA.
>>
>> KVM lacks support for this kind of non-linear VM_PFNMAP mapping, and these
>> patches should fix this.
>
> Hi Paolo,
>
> I have tested your patches with the mediated passthru patchset that is being
> reviewed in KVM and QEMU mailing list.
>
> The fault handler gets called successfully and the previously mapped memory gets
> unmmaped correctly via unmap_mapping_range.

Great, then I'll include them in 4.8.

Paolo