Re: [PATCH v2 00/12] KVM/X86: Introduce a new guest mapping interface

From: Paolo Bonzini
Date: Wed Jul 11 2018 - 06:26:32 EST


On 10/07/2018 14:06, Raslan, KarimAllah wrote:
> On Mon, 2018-04-16 at 13:10 +0200, Paolo Bonzini wrote:
>> On 15/04/2018 23:53, KarimAllah Ahmed wrote:
>>>
>>> Guest memory can either be directly managed by the kernel (i.e. have a "struct
>>> page") or they can simply live outside kernel control (i.e. do not have a
>>> "struct page"). KVM mostly support these two modes, except in a few places
>>> where the code seems to assume that guest memory must have a "struct page".
>>>
>>> This patchset introduces a new mapping interface to map guest memory into host
>>> kernel memory which also supports PFN-based memory (i.e. memory without 'struct
>>> page'). It also converts all offending code to this interface or simply
>>> read/write directly from guest memory.
>>>
>>> As far as I can see all offending code is now fixed except the APIC-access page
>>> which I will handle in a seperate patch.
>>
>> I assume the caching will also be a separate patch.
>>
>> It looks good except that I'd squash patches 4 and 9 together. But I'd
>> like a second set of eyes to look at it.
>
> BTW, Why did you want to squash these 2 patches specifically? They areÂ
> very unrelated to me. The only common thing is that they switch fromÂ
> code that supports only "struct page" to code that supports PFN only
> but this is also common for all other patches.

Probably at the time I was thinking they both affect cmpxchg, but really
they are gpte and emulator respectively. Looks like I have 12 more
patches on my review queue then! *ouch*

Paolo

>>
>> Thanks,
>>
>> Paolo
>>
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