linux-kernel - Re: [GIT PULL] Xen APIC hooks (with io_apic

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, 25 May 2009 07:55:28 +0300
From:	Avi Kivity <avi@...hat.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>,
	the arch/x86 maintainers <x86@...nel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Xen-devel <xen-devel@...ts.xensource.com>
Subject: Re: [GIT PULL] Xen APIC hooks (with io_apic_ops)

Ingo Molnar wrote:
>> We do something similar for Windows (by patching it) very 
>> successfully; Windows likes to touch the APIC TPR ~ 100,000 times 
>> per second, usually without triggering an interrupt.  We hijack 
>> these writes, do the checks in guest context, and only exit if the 
>> TPR write would trigger an interrupt.
>>     
>
> I suspect you aware of that this is about the io-apic not the local 
> APIC. The local apic methods are already driver-ized - and they sit 
> closer to the CPU so they matter more to performance.
>   

Yeah, I gave this as an example.  It's very different -- io-apic vs. 
local apic, paravirtualization vs. patching the guest behind its back, 
Linux vs. Windows.

Of course if we hook the io-apic EOI we'll want to hook the local apic 
EOI as well.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

--
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/