linux-kernel - Re: Fwd: [PATCH] x86: Use larger chunks in mtrr

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, 3 Sep 2015 04:45:42 +0200
From:	"Luis R. Rodriguez" <mcgrof@...e.com>
To:	Stuart Hayes <stuart.w.hayes@...il.com>
Cc:	tglx@...utronix.de, mingo@...hat.com,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	x86@...nel.org, prarit@...hat.com, mcgrof@...not-panic.com,
	Toshi Kani <toshi.kani@...com>
Subject: Re: Fwd: [PATCH] x86: Use larger chunks in mtrr_cleanup

On Mon, Aug 31, 2015 at 11:05:33AM -0500, Stuart Hayes wrote:
> Increase the range of chunk sizes tried in mtrr_cleanup() so it is able
> to map large memory configs into MTRRs.
> 
> Currently, mtrr_cleanup() will fail with large memory configurations,
> because it limits chunk_size to 2GB, which means that each MTRR can only
> cover 2GB of memory.  With a memory size of, say, 256GB, and ten variable
> MTRRs (such as some recent Intel CPUs have), it is not possible to set up
> the MTRRs to cover all of memory.

Linux drivers no longer use MTRR so why is the cleanup needed, ie, what would
happen if the cleanup is just skipped in your case ?

  Luis
--
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/