Re: [PATCH 15/18] KVM: MMU: Propagate the right fault back to the guest after gva_to_gpa

[Joerg Roedel <joro@8bytes.org>]

On Mon, Mar 15, 2010 at 09:36:52AM +0200, Avi Kivity wrote:
> On 03/03/2010 09:12 PM, Joerg Roedel wrote:
>> This patch implements logic to make sure that either a
>> page-fault/page-fault-vmexit or a nested-page-fault-vmexit
>> is propagated back to the guest.
>>
>> Signed-off-by: Joerg Roedel<joerg.roedel@amd.com>
>> ---
>>   arch/x86/kvm/mmu.h         |    1 +
>>   arch/x86/kvm/paging_tmpl.h |    2 ++
>>   arch/x86/kvm/x86.c         |   15 ++++++++++++++-
>>   3 files changed, 17 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
>> index 64f619b..b42b27e 100644
>> --- a/arch/x86/kvm/mmu.h
>> +++ b/arch/x86/kvm/mmu.h
>> @@ -47,6 +47,7 @@
>>   #define PFERR_USER_MASK (1U<<  2)
>>   #define PFERR_RSVD_MASK (1U<<  3)
>>   #define PFERR_FETCH_MASK (1U<<  4)
>> +#define PFERR_NESTED_MASK (1U<<  31)
>>    
>
>
> Why is this needed?  Queue an ordinary page fault page; the injection  
> code should check the page fault intercept and #VMEXIT if needed.

This is needed because we could have a nested page fault or an ordinary
page fault which need to be propagated.

	Joerg