linux-kernel - RE: [PATCH v3 1/4] KVM: Recover IRTE to remapped mode if the interrupt is not single-destination

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: <E959C4978C3B6342920538CF579893F00C2CB288@SHSMSX104.ccr.corp.intel.com>
Date:	Mon, 25 Jan 2016 12:26:46 +0000
From:	"Wu, Feng" <feng.wu@...el.com>
To:	Paolo Bonzini <pbonzini@...hat.com>,
	Radim Krcmár <rkrcmar@...hat.com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"Wu, Feng" <feng.wu@...el.com>
Subject: RE: [PATCH v3 1/4] KVM: Recover IRTE to remapped mode if the
 interrupt is not single-destination



> -----Original Message-----
> From: Paolo Bonzini [mailto:paolo.bonzini@...il.com] On Behalf Of Paolo
> Bonzini
> Sent: Monday, January 25, 2016 8:23 PM
> To: Radim Krcmár <rkrcmar@...hat.com>; Wu, Feng <feng.wu@...el.com>
> Cc: linux-kernel@...r.kernel.org; kvm@...r.kernel.org
> Subject: Re: [PATCH v3 1/4] KVM: Recover IRTE to remapped mode if the
> interrupt is not single-destination
> 
> 
> 
> On 22/01/2016 14:05, Radim Krcmár wrote:
> > > This is a good question. I also thought about this before, but after
> > > thinking it a bit more, seems we don't need to do this.
> > > If we don't do this, the in-flight interrupts will continue to be
> > > delivered in PI mode while we are changing it to remapped
> > > mode in IRTE. Even if we do this, the in-flight interrupts are
> > > also delivered in PI mode before setting 'SN' anyway, so seems
> > > we really don't need this, what is your opinion?
> > I'd remove it.
> 
> It may be necessary because IRTE writes (128 bits) are not atomic.

IRTE is updated atomically, I added the patch to support this. Please
refer to 344cb4e0b6f3a0dbef0643eacb4946338eb228c0.

Thanks,
Feng

> 
> If so, no need to send v5, I'll add it back.
> 
> Paolo