From: Gohar Irfan <goharirfan94@gmail.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>, xen-devel@lists.xen.org
Subject: Re: Page Table Entry Modifications
Date: Sun, 27 Sep 2015 07:26:11 +0000 [thread overview]
Message-ID: <CAPe5K8i896R3zAKTubc-A0xC-iQ04U7ws4P8amjMNzYXtPgVvQ@mail.gmail.com> (raw)
In-Reply-To: <CAPe5K8gZgqr-hYbRES_DMUN0DmLVs=RxNTgSjU9jK09UUP-qZw@mail.gmail.com>
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Could someone please help me with this? It's really important and urgent.
Thanks a lot!
On Wed, Sep 23, 2015 at 1:42 PM Gohar Irfan <goharirfan94@gmail.com> wrote:
> It is for a project, I'm trying to experiment with a couple of things.
>
> Could you please guide me how this could be achieved? Some relevant chunks
> of code, perhaps?
>
> Thanks!
>
> On Wed, Sep 23, 2015 at 1:35 PM Andrew Cooper <andrew.cooper3@citrix.com>
> wrote:
>
>> On 22/09/15 20:35, Gohar Irfan wrote:
>>
>> Hi All,
>>
>> I want to know if, in the case of HVM (shadow page tables), we can change
>> the machine frame number pointed to by a page table entry?
>>
>>
>> Yes - Xen is able to change the mfn in a pte.
>>
>>
>> An overly simplified example would be: let's say I have page number 10
>> that is pointing to machine frame number 10, but I would like it to point
>> to machine frame number 1?
>>
>>
>> Yes - that is in theory possible.
>>
>>
>> Can this be achieved inside the "sh_page_fault" function inside
>> "xen/arch/x86/mm/shadow/multi.c" as this seems like a relevant place for
>> this modification to me.
>>
>>
>> What are you trying to achieve? Modifications such as what you request
>> are possible, but you are exceedingly likely to end up with memory
>> corruption as a result.
>>
>>
>> ~Andrew
>>
>
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next prev parent reply other threads:[~2015-09-27 7:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-22 19:35 Page Table Entry Modifications Gohar Irfan
2015-09-23 8:35 ` Andrew Cooper
2015-09-23 8:42 ` Gohar Irfan
2015-09-27 7:26 ` Gohar Irfan [this message]
2015-09-27 14:57 ` Meng Xu
2015-09-27 16:04 ` Gohar Irfan
2015-09-28 19:09 ` Gohar Irfan
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