linux-kernel - Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor

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:	Thu, 20 Aug 2009 09:39:02 -0700
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Miroslav Rezanina <mrezanin@...hat.com>
CC:	linux-kernel@...r.kernel.org, xen-devel@...ts.xensource.com,
	Gianluca Guida <gianluca.guida@...rix.com>
Subject: Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor

On 08/20/09 00:47, Miroslav Rezanina wrote:
> there is handled e820 map in guest. However, this patch informs 
> hypervisor, that guest uses less memory than was assigned to it. 
> If hypervisor is not informed, memory is reserved for guest that
> do not need it. If hypervisor is informed, he decrease memory
> reservation for guest and unused memory is marked as free 
> for use by other guests.
>   

Yes.  But the guest will modify its own e820 map for a number of
reasons; for example: reducing its own memory, or clearing a space for
the PCI hole.  In general we want to free any underlying pages which
don't correspond to E820_RAM regions.

    J
--
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/