linux-kernel - Re: [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well as x86

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: <4BBD18B0.6010302@zytor.com>
Date:	Wed, 07 Apr 2010 16:43:44 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Yinghai <yinghai.lu@...cle.com>
CC:	Bjorn Helgaas <bjorn.helgaas@...com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, linux-pci@...r.kernel.org,
	x86@...nel.org, linux-kernel@...r.kernel.org,
	Andy Isaacson <adi@...apodia.org>,
	Thomas Renninger <trenn@...e.de>
Subject: Re: [PATCH] x86: Reserve legacy VGA MMIO area for x86_64 as well
 as x86_32

On 04/07/2010 03:45 PM, Yinghai wrote:
> 
> It seem another thread, erission has one model without VGA, and they use that area for other device MMIO.
> 
> current for 64bit, We remove [0xa0000, 0x100000) from e820 map if those area is E820_RAM.
> 

Removing is not the same thing as reserving!

A range with no type in E820 is address space available for allocation;
whereas in order to be reserved, it should be E820_RESERVED.

> in e820_reserve_resources(), kernel will reserve range < 1M according to e820 map.
> that is before pci BAR is claimed.
> 
> or you can add
> boot_params.screen_info.orig_video_isVGA == 1
> or double check scan pci tree to see if video is there or not

Perhaps boot_params.screen_info.orig_video_isVGA != 1 because he's not
booting in a text mode?
	
	-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/