From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Wang Subject: Re: [PATCHv2 2 of 2] Move IOMMU faults handling into softirq for AMD-Vi. Date: Wed, 18 Jan 2012 11:40:06 +0100 Message-ID: <4F16A186.4080303@amd.com> References: <1326876800.2375.18.camel@Abyss> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1326876800.2375.18.camel@Abyss> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Dario Faggioli Cc: Tim Deegan , "allen.m.kay@intel.com" , xen-devel@lists.xensource.com, Keir Fraser , Jan Beulich List-Id: xen-devel@lists.xenproject.org On 01/18/2012 09:53 AM, Dario Faggioli wrote: > On Tue, 2012-01-17 at 11:17 +0000, Keir Fraser wrote: >>> Dealing with interrupts from AMD-Vi IOMMU(s) is deferred to a softirq-tasklet, >>> raised by the actual IRQ handler. To avoid more interrupts being generated >>> (because of further faults), they must be masked in the IOMMU within the low >>> level IRQ handler and enabled back in the tasklet body. Notice that this may >>> cause the log to overflow, but none of the existing entry will be overwritten. >>> >>> Signed-off-by: Dario Faggioli >> >> This patch needs fixing to apply to xen-unstable tip. Please do that and >> resubmit. >> > I see. I can easily rebase the patch but there are functional changes > involved, so I'd like to know what you think it's best to do first. > > In particular, the clash is against Wei's patches introducing PPR. So > now the IOMMU interrupt handler checks both event log and ppr log. > > Question is, should I move _BOTH_ these checks into softirq or just > defer event log processing, and leave ppr log handling in hard-irq > context? Quickly looking at the new specs, it seems to me that deferring > both should be fine, but I'd really appreciate your thoughts... I think put both event log and ppr log into softirq is fine. If you could have a patch like this, I can do a quick test on my machine. Thanks, Wei > Wei, Jan, Tim? > > Thanks and regards, > Dario >