linux-kernel - Re: This combination of AMDprocessors is not suitable for SMP?

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] [day] [month] [year] [list]

Date:	Thu, 23 Jul 2009 12:34:40 +0200
From:	Andre Przywara <andre.przywara@....com>
To:	Michael Tokarev <mjt@....msk.ru>
CC:	Linux-kernel <linux-kernel@...r.kernel.org>,
	KVM list <kvm@...r.kernel.org>
Subject: Re: This combination of AMDprocessors is not suitable for SMP?

Michael Tokarev wrote:
> (yes there's no typo in $subject, it's an old formatting
> bug in printk).
> 
> When booting kvm guest on an AMD CPU, guest kernel prints
> this warning:
> 
>  WARNING: This combination of AMDprocessors is not suitable for SMP.
> 
> be it SMP or UP guest.  What's wrong with this "combination",
> and can it be fixed?
The qemu64 CPU model KVM injects into the guest lets it see an AMD K7 
with 64bit extension. Only some AMD K7 (Athlon-MP) were certified for 
SMP support, so this code warns the user about an unsupported hardware.
When running KVM you can ignore this warning, as it only applies to 
non-KVM capable processors and has no meaning for virtual SMP anyway.

If you like this warning to disappear, you can use "-cpu host" (and 
probably loose migration capability) or wait for the new safe64 CPU 
type, which will use family 15 instead of 6.

Regards,
Andre.

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
Tel: +49 351 448 3567 12
----to satisfy European Law for business letters:
Advanced Micro Devices GmbH
Karl-Hammerschmidt-Str. 34, 85609 Dornach b. Muenchen
Geschaeftsfuehrer: Thomas M. McCoy; Giuliano Meroni
Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632

--
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/