linux-kernel - Re: [Xen-devel] [RFC PATCH] Boot PV guests with more than 128GB (v1) for 3.7

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 27 Jul 2012 11:17:41 +0100
From:	"Jan Beulich" <JBeulich@...e.com>
To:	"Ian Campbell" <Ian.Campbell@...rix.com>
Cc:	"Ian Jackson" <Ian.Jackson@...citrix.com>,
	"xen-devel" <xen-devel@...ts.xen.org>,
	"Konrad Rzeszutek Wilk" <konrad.wilk@...cle.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [Xen-devel] [RFC PATCH] Boot PV guests with more than
 128GB (v1) for 3.7

>>> On 27.07.12 at 12:00, Ian Campbell <Ian.Campbell@...rix.com> wrote:
> On Fri, 2012-07-27 at 08:34 +0100, Jan Beulich wrote:
>> >>> On 26.07.12 at 22:47, Konrad Rzeszutek Wilk <konrad.wilk@...cle.com> wrote:
>> >  2). Allocate a new array, copy the existing P2M into it,
>> >     revector the P2M tree to use that, and return the old
>> >     P2M to the memory allocate. This has the advantage that
>> >     it sets the stage for using XEN_ELF_NOTE_INIT_P2M
>> >     feature. That feature allows us to set the exact virtual
>> >     address space we want for the P2M - and allows us to
>> >     boot as initial domain on large machines.
>> 
>> And I would hope that the tools would get updated to recognize
>> this note too, so that huge DomU-s would become possible as
>> well.
> 
> Does this help us with >160GB 32 bit PV guests too? I'm guessing not
> since the real limitation there is the relatively small amount of kernel
> address space.

Correct - 32-bit PV guests are limited anyway (and it's for a
reason the Dom0 support in the hypervisor only deals with
64-bit ones). And honestly, considering the huge page
information table such a memory amount would require, I
doubt this big a PV guest would even boot (or if it does, be
of any use).

Jan

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/