How to allocate a page inside the guest OS from Xen

How to allocate a page inside the guest OS from Xen

[Abhinav Srivastava]

Hi there,

In my project, I have to allocate a memory page inside the guest OS from the Xen hypervisor. The alloc_domheap_page(d) function allocates a single page from the dom heap, which looks okey for my purpose. But, I do not know how to add the allocated page into the guest page table, so that guest can access this page. I do not want to allocate a Xen page and share it with the guest. 

My question is: how do I make my guest OS aware of this page without doing anything inside the guest OS. Is there any function in Xen that directly adds a page into the guest OS address space or I have to walk on the guest page tables and add this page manually.

Any help would be appreciated?

Thanks,
Abhinav



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Re: How to allocate a page inside the guest OS from Xen

[James (song wei)]

I am not clear why did you want to let VM aware it. Gerenally speaking, mfn
-> gfn in p2m table. If the Guest OS can acess the pfn without "Page Fault"
, perhaps could satisfy you.  Hope this is helpful.

-James (song wei)


Abhinav Srivastava-2 wrote:
> 
> Hi there,
> 
> In my project, I have to allocate a memory page inside the guest OS from
> the Xen hypervisor. The alloc_domheap_page(d) function allocates a single
> page from the dom heap, which looks okey for my purpose. But, I do not
> know how to add the allocated page into the guest page table, so that
> guest can access this page. I do not want to allocate a Xen page and share
> it with the guest. 
> 
> My question is: how do I make my guest OS aware of this page without doing
> anything inside the guest OS. Is there any function in Xen that directly
> adds a page into the guest OS address space or I have to walk on the guest
> page tables and add this page manually.
> 
> Any help would be appreciated?
> 
> Thanks,
> Abhinav
> 
> 
> 
>       Keep up with people you care about with Yahoo! India Mail. Learn
> how. http://in.overview.mail.yahoo.com/connectmore
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel
> 
> 

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