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:	Mon, 3 Nov 2008 11:33:06 -0200
From:	Eduardo Habkost <ehabkost@...hat.com>
To:	Avi Kivity <avi@...hat.com>
Cc:	Ingo Molnar <mingo@...e.hu>, Andrey Borzenkov <arvidjaar@...l.ru>,
	Avi Kivity <avi@...ranet.com>, mingo@...hat.com,
	Andrew Morton <akpm@...l.org>,
	"Rafael J. Wysocki" <rjw@...k.pl>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	"Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH] Use BIOS reboot on Toshiba Portege 4000

On Mon, Nov 03, 2008 at 12:02:53PM +0200, Avi Kivity wrote:
> Ingo Molnar wrote:
>>> Subject: [PATCH] Use BIOS reboot on Toshiba Portege 4000
>>>
>>> From: Andrey Borzenkov <arvidjaar@...l.ru>
>>>
>>> After commit c7ffa6c26277b403920e2255d10df849bd613380 which defaults
>>> to reboot via ACPI keyboard is dead on Toshiba Portege 4000 upon reboot.
>>> Power off is required to revive it again. Add DMI entry to force BIOS
>>> reboot method as it was before.
>>>
>>> Signed-off-by: Andrey Borzenkov <arvidjaar@...l.ru>
>>>     
>>
>> Avi, i expect more boxes to be affected by this bug, and the DMI  
>> solution just does not scale.
>>
>> So could we please disable VMX from the emergency-shutdown code  
>> instead of twiddling with the reboot method?
>>
>> Something like this might work as well: iff VMX is enabled, we just do  
>> smp_send_stop() (instead of skipping it) which should take care of  
>> this.
>>   
>
> There is already some code being worked on for kdump (which suffers from  
> the same symptoms), only kdump uses NMI IPIs for increased stopping  
> power.  Eduardo, can you take a look at porting it to emergency reboot?

We probably need to disable vmx on all CPUs, but emergency reboot skips
native_smp_send_stop() (where we could hook a virt_disable call in).

As relying on IPIs defeats the whole point of emergency_restart, a proper
fix will need to use NMIs like the kdump code does.

-- 
Eduardo
--
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/

Powered by blists - more mailing lists