From: Keir Fraser <keir.xen@gmail.com>
To: Tim Deegan <tim@xen.org>, Jan Beulich <JBeulich@suse.com>
Cc: xen-devel@lists.xen.org
Subject: Re: [PATCH] x86/mm: remove the linear mapping of the p2m tables
Date: Thu, 13 Sep 2012 15:58:34 +0100 [thread overview]
Message-ID: <CC77B32A.3EA62%keir.xen@gmail.com> (raw)
In-Reply-To: <20120913144251.GC12881@ocelot.phlegethon.org>
On 13/09/2012 15:42, "Tim Deegan" <tim@xen.org> wrote:
>> Is that also going to remain true when we won't be able to 1:1-
>> map all of the memory anymore once we break the current 5Tb
>> barrier? If not, it would probably be worthwhile keeping that
>> code.
>
> Ah, 5TB is a smaller limit than I thought we had. Yes, better leave it
> alone, so. Though TBH finding some way to use a bit more virtual
> address space for Xen seems like a good idea anyway, since this won't be
> the only place we'll want to avoid TLB flushes.
For HVM or PVH guests, where this HAP code would be used, clearly Xen can
use all the virtual address space it wants. It will almost certainly make
sense for Xen to have a 1:1 physical mapping of all memory when running such
a guest, and only do mapcache type tricks when running legacy PV guests.
-- Keir
next prev parent reply other threads:[~2012-09-13 14:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 14:01 [PATCH] x86/mm: remove the linear mapping of the p2m tables Tim Deegan
2012-09-13 14:23 ` Jan Beulich
2012-09-13 14:42 ` Tim Deegan
2012-09-13 14:58 ` Keir Fraser [this message]
2012-09-13 15:08 ` Jan Beulich
2012-09-13 15:17 ` Keir Fraser
2012-09-13 15:36 ` Jan Beulich
2012-09-13 15:11 ` Tim Deegan
2012-09-13 15:18 ` Keir Fraser
2012-09-13 20:43 ` Konrad Rzeszutek Wilk
2012-09-13 21:14 ` Keir Fraser
2012-09-14 20:31 ` Konrad Rzeszutek Wilk
2012-09-14 20:55 ` Keir Fraser
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