linux-kernel - Re: [PATCH v3 0/2] kvm: level irqfd and new eoifd

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: <4FFD5A2B.2040605@redhat.com>
Date:	Wed, 11 Jul 2012 13:49:15 +0300
From:	Avi Kivity <avi@...hat.com>
To:	Jan Kiszka <jan.kiszka@...mens.com>
CC:	Alex Williamson <alex.williamson@...hat.com>,
	"mst@...hat.com" <mst@...hat.com>,
	"gleb@...hat.com" <gleb@...hat.com>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 0/2] kvm: level irqfd and new eoifd

On 07/11/2012 01:18 PM, Jan Kiszka wrote:
> On 2012-07-11 11:53, Avi Kivity wrote:
>> On 07/03/2012 10:21 PM, Alex Williamson wrote:
>>> Here's the latest iteration of adding an interface to assert and
>>> de-assert level interrupts from external drivers like vfio.  These
>>> apply on top of the previous argument cleanup, documentation, and
>>> sanitization patches for irqfd.  It would be great to get this queued
>>> in next for linux 3.6.
>>>
>>> I believe I've addressed all the previous comments, including fixing
>>> the locking problems in eoifd.  I've run this with lockdep adding
>>> and removing level irqfd/eoifd pairs without any problems.  Please
>>> let me know if there are any further comments.  Thanks,
>> 
>> Is there any performance justification for level irqfd?  Don't all
>> new/high bandwidth devices support msi, and this is just a legacy path?
> 
> I think we've been there before, but the situation hasn't improved much:
> 
> Apparently, some GPUs still prefer INTx over MSI. Some wireless chipsets
> too. 

I'd appreciate a couple of examples for formality's sake.

> And then there is not easily replaceable legacy hardware like old
> telephony adapters or industrial I/O cards etc. that want this.

I imagine legacy hardware will live with the speed of routing through
qemu, when running on modern platforms.

-- 
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/