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RE: [Xen-devel] guest physical to xen machine copy?

To: 'Dan Magenheimer' <dan.magenheimer@xxxxxxxxxx>, "Xen-Devel (E-mail)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] guest physical to xen machine copy?
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Sun, 28 Sep 2008 10:37:36 +0800
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Thread-topic: [Xen-devel] guest physical to xen machine copy?
You can try gfn_to_mfn...


>From: Dan Magenheimer
>Sent: 2008年9月28日 5:33
>Sorry for my poor x86 memory model knowlege...
>In some code I am working on, I currently pass the
>address of a guest page from a domain via a hypercall
>and in Xen either copy to or from the guest page
>__copy_from_guest(xen_va, guest_va, PAGE_SIZE)
>__copy_to_guest(guest_va, xen_va, PAGE_SIZE)
>where guest_va is declared as a XEN_GUEST_HANDLE(void)
>Now I'd like to switch the hypercall interface so
>that the domain passes a guest physical address
>(or guest physical frame number) instead of a guest
>virtual address.
>I see code that does get_gpfn_from_mfn() but not
>the opposite.  What do I need to do to copy a
>page of data from a guest pfn to a Xen mfn (or
>vice versa)?  And is a guest physical address
>still referenced as a XEN_GUEST_HANDLE?
>It's probably very simple but I can't find it...
>P.S. This has to work on 32- or 64-bit guests to
>both 32- and 64-bit hypervisors.
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