Re: XENFEAT_supervisor_mode_kernel ???

[Keir Fraser <keir.fraser@eu.citrix.com>]

No, not really. The hypervisor changes could likely not be that large.

 -- Keir

On 20/11/08 23:03, "Mukesh Rathor" <mukesh.rathor@oracle.com> wrote:

> Oh, cool. I was looking at syscalls on PV x86_64 guests, and one of my
> thoughts was running in HVM mode but do all MMU stuff using hypercalls like
> PV. Other than having to change the hyp domain create portions, setting things
> up, is there a technical reason it can't be done today... thanks, Mukesh
> 
> Keir Fraser wrote:
>> On 20/11/08 22:42, "Mukesh Rathor" <mukesh.rathor@oracle.com> wrote:
>> 
>>> I'm trying ot figure out what that's all about? I see in 64 PV domU, it's
>>> being checked prior to returning from syscall.  On the xen side, I see it
>>> tied
>>> to supervisor_mode_kernel, but the only info I find is changelog comment
>>> which
>>> suggests it's purpose is to allow dom0 run in ring 0... So why the check in
>>> a
>>> domU kernel?
>> 
>> It's useful if the hypervisor runs the guest kernel in ring 0. Current Xen
>> doesn't do that, but in future we may run 64-bit PV guests in HVM context as
>> that may actually be faster.
>> 
>>  -- Keir
>>