WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] about: XENMEM_machphys_mfn_list

To: "BVK Chaitanya" <bayapuneni_chaitanya@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] about: XENMEM_machphys_mfn_list
From: Lin.Yu <yulin724@xxxxxxxxx>
Date: Fri, 18 Jul 2008 17:22:26 +0800
Cc: Xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 18 Jul 2008 02:22:48 -0700
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type:references; bh=C7cKgeDsmUZLv42RJrRqz5BgdifRtlLEQB0iYrsOOAc=; b=ves3IUKYpxEiCnQIUAjoicXspMp51Lt/Mmob2pob4E3UkPhepptCcfe+KnW+HI3IYs 77usqIS1SeFgeFsurEzQeahPWU/eQaL2A5TkOPDryjzArXkxfvZIZPK2iTk4uNavYXtF ZI1cSO3HGIp/CS6Kba0f3JcCk6OD3gZJbw97o=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:references; b=sFYqj165gwdhC8QPZlyPZi6ZvSlqNfqXI1r+D0ihVQ/j9x0l1iWKAS7gzT0qVL9izZ oBf7rNDBwGrPFPSap32HccBdAjAHN2QA0CK1CK2HS7ooXYkaSAlXjEU5cvhsmhzJ5UYd 8yhZrcH3fHbObh+xi5aXied2mmvpRaXsVfgzc=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <48805E0F.9000208@xxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <8eeed7950807180149y44b1a2eq56e866a490c2c2af@xxxxxxxxxxxxxx> <48805E0F.9000208@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Got it.
But why 2MB? I have no any clue about it.

-- Lin
On Fri, Jul 18, 2008 at 5:10 PM, BVK Chaitanya <bayapuneni_chaitanya@xxxxxxxxxxxx> wrote:
Lin.Yu wrote:

XENMEM_machphys_mfn_list command is used to acquire the mapping between the pseudo-physical to machine. And the hypercall will fill in the struct xen_machphys_mfn_list.

I do not understand "This table is an array of pseudo-physical frame numbers of the start of 2MB extents, corresponding to 2MB rangs in the pseudo-physical address space".
"This table" means the array pointed by xen_machphys_mfn_list.extent_start.

I am reading the code about this struct, still in confusion.
:-)
Who can help me?



AFAIU, here "table" is nothing more than an array of xen_pfn_ts.

Only complication is, mfns returned are `base-mfns' for 2MB memory regions.

For example, if mfn 100 is returned, it means mfns 100-612 hold the 2MB region (612 = 100 + 512; 512 pages make 2MB)


--
bvk-chaitanya



--
Best Regards,
-- Lin.Yu
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>