Re: PCI Passthrough ARM Design : Draft1

[Julien Grall <julien.grall@citrix.com>]

On 16/06/2015 08:02, Roger Pau Monné wrote:
> Hello,
>
> El 16/06/15 a les 7.42, Manish Jaggi ha escrit:
> [...]
>>>>> Beware that the 1:1 mapping doesn't fit with the current guest memory
>>>>> layout which is pre-defined at Xen build time. So you would also have
>>>>> to make it dynamically or decide to use the same memory layout as the
>>>>> host.
>>>> If same layout as host used, would there be any issue?
>>> I'm not sure that a 1:1 mapping is any different to the host layout. But
>>> in any case, the host layout also doesn't match the guest layout, so it
>>> has the same issues.
>> There is a domctl on x86 DOMCTL_iomem_permission which looks doing the
>> same thing as the map_mmio hypercall which I am proposing. I am not sure
>> if it does a 1:1. Do you have more info on it?
>
> No, this hypercall only sets the permissions of IO memory ranges, but
> AFAICT it doesn't touch the p2m at all.

Correct.


-- 
Julien Grall