From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Gohar Irfan <goharirfan94@gmail.com>, xen-devel@lists.xen.org
Subject: Re: Page Table Entry Modifications
Date: Wed, 23 Sep 2015 09:35:19 +0100 [thread overview]
Message-ID: <56026447.7000901@citrix.com> (raw)
In-Reply-To: <CAPe5K8h=vSdjr+pEMM2dUY326Vw56c+bcKgxWRNSfcNSgqigrw@mail.gmail.com>
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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:[~2015-09-23 8:35 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 [this message]
2015-09-23 8:42 ` Gohar Irfan
2015-09-27 7:26 ` Gohar Irfan
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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