lkml.org 
[lkml]   [2020]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 00/11] KVM: Support guest MAXPHYADDR < host MAXPHYADDR
From
Date
On 6/22/20 10:23 AM, Paolo Bonzini wrote:
> On 22/06/20 17:08, Mohammed Gamal wrote:
>>> Also, something to consider. On AMD, when memory encryption is
>>> enabled (via the SYS_CFG MSR), a guest can actually have a larger
>>> MAXPHYADDR than the host. How do these patches all play into that?
>
> As long as the NPT page tables handle the guest MAXPHYADDR just fine,
> there's no need to do anything. I think that's the case?

Yes, it does.

Thanks,
Tom

>
> Paolo
>
>> Well the patches definitely don't address that case. It's assumed a
>> guest VM's MAXPHYADDR <= host MAXPHYADDR, and hence we handle the case
>> where a guests's physical address space is smaller and try to trap
>> faults that may go unnoticed by the host.
>>
>> My question is in the case of guest MAXPHYADDR > host MAXPHYADDR, do we
>> expect somehow that there might be guest physical addresses that
>> contain what the host could see as reserved bits? And how'd the host
>> handle that?
>

\
 
 \ /
  Last update: 2020-06-22 18:36    [W:0.060 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site