linux-kernel - Re: Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override.

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]

Message-ID: <47845972.9090803@zytor.com>
Date:	Tue, 08 Jan 2008 21:19:46 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Zachary Amsden <zach@...are.com>
CC:	"David P. Reed" <dpreed@...d.com>, Avi Kivity <avi@...amnet.com>,
	Christer Weinigel <christer@...nigel.se>,
	Ondrej Zary <linux@...nbow-software.org>,
	Rene Herman <rene.herman@...access.nl>,
	Bodo Eggert <7eggert@....de>, Ingo Molnar <mingo@...e.hu>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Paul Rolland <rol@...917.net>, Pavel Machek <pavel@....cz>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...hat.com>,
	rol <rol@...be.net>
Subject: Re: Re: [PATCH] x86: provide a DMI based port 0x80
 I/O delay override.

Zachary Amsden wrote:
> 
> BTW, it isn't ever safe to pass port 0x80 through to hardware from a
> virtual machine; some OSes use port 0x80 as a hardware available scratch
> register (I believe Darwin/x86 did/does this during boot).

That's funny, because there is definitely no guarantee that you get back 
what you read (well, perhaps there is on Apple.)

	-hpa
--
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/