linux-kernel - Re: [PATCH 1/9] KVM: SVM: Notify nested hypervisor of lost event injections

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] [day] [month] [year] [list]

Message-ID: <4AD2F83F.2020604@redhat.com>
Date:	Mon, 12 Oct 2009 11:34:55 +0200
From:	Avi Kivity <avi@...hat.com>
To:	Alexander Graf <agraf@...e.de>
CC:	Joerg Roedel <joerg.roedel@....com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/9] KVM: SVM: Notify nested hypervisor of lost event
 injections

On 10/08/2009 06:46 PM, Alexander Graf wrote:
>
>
> Am 08.10.2009 um 18:38 schrieb Avi Kivity <avi@...hat.com>:
>
>> On 10/08/2009 06:32 PM, Joerg Roedel wrote:
>>> No. The L1 guest needs to execute VMRUN with an interrupt to inject to
>>> the L2 guest with event_inj. On that VMRUN instruction emulation an
>>> interrupt becomes pending which causes an immediate #vmexit from L2 to
>>> L2 again without even entering the L2 guest. The bug was that in this
>>> case the event which the L1 tried to inject in the L2 was lost because
>>> it was not copied to exit_int_info.
>>>
>>
>> (from L1 to L0?)
>>
>> Wow.  Alex, how did you find this?
>
> Hyper-V got stuck and I was trying to think of possible reasons 
> looking at the logs :-).
> Fortunately this patch also seemed to make things work better with KVM 
> in KVM.
>
> Doesn't really help with regression testing though...

We could write a dummy hypervisor that injects tons of interrupts and 
hope for a host interrupt in there.  I'm worried about such a mass of 
complex code that gets very little testing.

-- 
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/