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A clarification:Â

I also want to COPY the contents of the frames, so there will be no memory corruption. In essence, only the frame numbers will be changed.Â

My other question, which is sort of a follow up to this, may be relevant:

"Given two GMFN in shadow paging (HVM) is there a way to swap their contents? Let's say I have GMFN x and GMFN y, I want to put the contents of x in y and the contents of y in x. "

Thanks a lot!

On Sun, Sep 27, 2015 at 9:04 PM Gohar Irfan <goharirfan94@xxxxxxxxx> wrote:

This might not seem useful or anything, but this is a part of an experiment so I will describe what I'm trying to do:

Divide the memory into two equal halves and call them A and B.Â
Let's say region A has 10 pages, from page numbers 1 to 10. Region B has 10 pages from page numbers 11 to 20 (hypothetical, of course.)
When a page from region B (page number 11 to 20) is being accessed, say page 15, then swap the contents of page 15 with the contents of one of the pages from region A, say page 5.Â
To achieve this, I need some help. In the default scenario, page 15 points to frame X and page 5 points to frame Y. I want to make page 15 point to frame Y and page 5 to frame X of the memory.

I want to run this experiment and find the degradation in performance for a project.
If some portion of this seems vague, I can explain. But I urgently need help on how to achieve this.

My understanding is that it can be done in the page fault handler of shadow page tables. I have mentioned the relevant file and function earlier in this thread.

Thanks a lot!

On Sun, Sep 27, 2015 at 7:57 PM Meng Xu <xumengpanda@xxxxxxxxx> wrote:
2015-09-23 4:42 GMT-04:00 Gohar Irfan <goharirfan94@xxxxxxxxx>:
>
> It is for a project, I'm trying to experiment with a couple of things.

Well, this is too general... Everything can be a project. People tries
to know what exact things you want to achieve so that they can figure
out if you are heading the correct direction.

Meng

Re: [Xen-devel] Page Table Entry Modifications