linux-kernel - Re: [PATCH] KVM: x86: Kick VCPU outside PIC lock again

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: <4B84FF2F.5040705@redhat.com>
Date:	Wed, 24 Feb 2010 12:27:59 +0200
From:	Avi Kivity <avi@...hat.com>
To:	Jan Kiszka <jan.kiszka@...mens.com>
CC:	Thomas Gleixner <tglx@...utronix.de>, KVM <kvm@...r.kernel.org>,
	Gleb Natapov <gleb@...hat.com>,
	RT <linux-rt-users@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] KVM: x86: Kick VCPU outside PIC lock again

On 02/24/2010 12:22 PM, Jan Kiszka wrote:
> Avi Kivity wrote:
>    
>> On 02/24/2010 12:13 PM, Jan Kiszka wrote:
>>      
>>>
>>>        
>>>> I see.  Won't we hit the same issue when we call pic functions from
>>>> atomic context during the guest entry sequence?
>>>>
>>>>
>>>>          
>>> If there are such call paths, for sure. What concrete path(s) do you
>>> have in mind?
>>>
>>>
>>>        
>> vcpu_enter_guest() ->  inject_pending_event() ->
>> kvm_cpu_{has,get}_interrupt() ->  various pic functions if you're unlucky.
>>      
> But do they kick anyone or just check/pull information?

Probably not, kicking should be a side effect (or rather the main 
effect) of queueing an interrupt, not dequeuing it.

> Never saw any
> warnings during my tests last year (granted: with older -rt and kvm
> versions).
>    

Well, most guests kill the pic early on.  Will apply the patch.

-- 
error compiling committee.c: too many arguments to function

--
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/