linux-kernel - Re: x86.git: mtrr trimming removes all memory under kvm

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, 24 Jan 2008 17:49:00 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
CC:	Yinghai Lu <Yinghai.Lu@....COM>, Ingo Molnar <mingo@...e.hu>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: x86.git: mtrr trimming removes all memory under kvm

Jeremy Fitzhardinge wrote:
> When booting a current x86.git kernel under kvm, I get this:
> 
> (qemu) Linux version 2.6.24-rc8 (jeremy@ezr) (gcc version 4.1.2 20070925 
> (Red Hat 4.1.2-33)) #1928 SMP PREEMPT Thu Jan 24 17:09:04 PST 2008
> early_ioremap_init()
> BIOS-provided physical RAM map:
> BIOS-e820: 0000000000000000 - 000000000009fc00 (usable)
> BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved)
> BIOS-e820: 00000000000e8000 - 0000000000100000 (reserved)
> BIOS-e820: 0000000000100000 - 000000001fff0000 (usable)
> BIOS-e820: 000000001fff0000 - 0000000020000000 (ACPI data)
> BIOS-e820: 00000000fffc0000 - 0000000100000000 (reserved)
> console [earlyser0] enabled
> 0MB HIGHMEM available.
> 511MB LOWMEM available.
> Scan SMP from c0000000 for 1024 bytes.
> Scan SMP from c009fc00 for 1024 bytes.
> Scan SMP from c00f0000 for 65536 bytes.
> Scan SMP from c009fc00 for 1024 bytes.
> ***************
> **** WARNING: likely BIOS bug
> **** MTRRs don't cover all of memory, trimmed 131056 pages
> ***************

Looks like the code doesn't check that the CPU *has* MTRRs...

	-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/