linux-kernel - Re: [PATCH] Fix emergency_restart (sysrq-b) with kvm loaded on Intel hosts

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20080825093020.GA5617@elte.hu>
Date:	Mon, 25 Aug 2008 11:30:20 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Avi Kivity <avi@...ranet.com>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: Re: [PATCH] Fix emergency_restart (sysrq-b) with kvm loaded on
	Intel hosts


* Avi Kivity <avi@...ranet.com> wrote:

> Ingo Molnar wrote:
>> * Avi Kivity <avi@...ranet.com> wrote:
>>
>>   
>>> Enabling Intel VT has the curious side effect whereby the INIT signal 
>>> is blocked.  Rather than comment on the wisdom of this side effect,  
>>> this patch adds an emergency restart reboot notifier, and modifies 
>>> the kvm reboot notifier to disable VT on emergency reboot.
>>>     
>>
>> looks good to me - i was bitten by that problem on a testbox.
>>   
>
> I'm a little worried about making emergency restart more complex.
>
> Another thing that worries me is that emergency_restart() doesn't 
> reset the box -- it sends INIT.  We could do better by using the ACPI 
> FADT reset register (hopefully that's connected to RESET).

reboot was always a bit fragile - i think we should only do that if we 
find a box where the FADT reset works better than the first-wave 
approaches we try.

> Which seems to be what we want? Maybe we should just try acpi_reboot() 
> before the other stuff.

perhaps in a separate commit, for v2.6.28 at the earliest.

	Ingo
--
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/