All of lore.kernel.org
 help / color / mirror / Atom feed
* kvm vmx shadow paging question
@ 2016-08-13 14:38 Mika Penttilä
  2016-08-13 15:47 ` Mika Penttilä
  0 siblings, 1 reply; 3+ messages in thread
From: Mika Penttilä @ 2016-08-13 14:38 UTC (permalink / raw)
  To: kvm

Hi,

While studying the vmx code, and the shadow page tables usage (no ept involved),
I wondered the GUEST_CR3 usage. If no ept, GUEST_CR3 points to the shadow tables.
But the format of sptes is always 64 bit. How is that with 32 bit hosts, is the GUEST_CR3
similar to EPT format, 4 level 64 bit always or how is this working on 32 bit?

Thanks,
Mika


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: kvm vmx shadow paging question
  2016-08-13 14:38 kvm vmx shadow paging question Mika Penttilä
@ 2016-08-13 15:47 ` Mika Penttilä
  2016-08-15 14:12   ` Mika Penttilä
  0 siblings, 1 reply; 3+ messages in thread
From: Mika Penttilä @ 2016-08-13 15:47 UTC (permalink / raw)
  To: kvm, LKML

On 13.08.2016 17:38, Mika Penttilä wrote:

> Hi,
>
> While studying the vmx code, and the shadow page tables usage (no ept involved),
> I wondered the GUEST_CR3 usage. If no ept, GUEST_CR3 points to the shadow tables.
> But the format of sptes is always 64 bit. How is that with 32 bit hosts, is the GUEST_CR3
> similar to EPT format, 4 level 64 bit always or how is this working on 32 bit?
>
> Thanks,
> Mika
>
Hmm seems non PAE 32 bit host without ept enabled is not supported combination, right ?

--Mika

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: kvm vmx shadow paging question
  2016-08-13 15:47 ` Mika Penttilä
@ 2016-08-15 14:12   ` Mika Penttilä
  0 siblings, 0 replies; 3+ messages in thread
From: Mika Penttilä @ 2016-08-15 14:12 UTC (permalink / raw)
  To: kvm, LKML

On 13.08.2016 18:47, Mika Penttilä wrote:

> On 13.08.2016 17:38, Mika Penttilä wrote:
>
>> Hi,
>>
>> While studying the vmx code, and the shadow page tables usage (no ept involved),
>> I wondered the GUEST_CR3 usage. If no ept, GUEST_CR3 points to the shadow tables.
>> But the format of sptes is always 64 bit. How is that with 32 bit hosts, is the GUEST_CR3
>> similar to EPT format, 4 level 64 bit always or how is this working on 32 bit?
>>
>> Thanks,
>> Mika
>>
> Hmm seems non PAE 32 bit host without ept enabled is not supported combination, right ?
>
> --Mika
>
>

Ping, am I correct that for using shadow mmu with x86 kvm host you need at least 32bit PAE enabled host
(because shadow ptes are always 64 bit, in PAE or long format)?

--Mika

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2016-08-15 14:47 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-08-13 14:38 kvm vmx shadow paging question Mika Penttilä
2016-08-13 15:47 ` Mika Penttilä
2016-08-15 14:12   ` Mika Penttilä

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.