From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [PATCH v2 11/13] x86/PMU: Handle PMU interrupts for PV guests Date: Wed, 25 Sep 2013 11:19:46 -0400 Message-ID: <5242FF12.9090809@oracle.com> References: <1379670132-1748-1-git-send-email-boris.ostrovsky@oracle.com> <1379670132-1748-12-git-send-email-boris.ostrovsky@oracle.com> <5243106702000078000F6524@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VOqqX-0000n6-0g for xen-devel@lists.xenproject.org; Wed, 25 Sep 2013 15:17:45 +0000 In-Reply-To: <5243106702000078000F6524@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: suravee.suthikulpanit@amd.com, George.Dunlap@eu.citrix.com, jacob.shin@amd.com, eddie.dong@intel.com, dietmar.hahn@ts.fujitsu.com, jun.nakajima@intel.com, xen-devel List-Id: xen-devel@lists.xenproject.org On 09/25/2013 10:33 AM, Jan Beulich wrote: >>>> On 20.09.13 at 11:42, Boris Ostrovsky wrote: >> Add support for handling PMU interrupts for PV guests, make these interrupts >> NMI instead of PMU_APIC_VECTOR vector. Depending on vpmu_mode forward the >> interrupts to appropriate guest (mode is VPMU_ON) or to dom0 (VPMU_DOM0). > Is using NMIs here a necessity? I guess not, in which case I'd really > like this to be a (perhaps even non-default) option controllable via > command line option. It is not a necessity but using NMIs will allow us to profile code that runs with interrupts disabled. >> - * This interrupt handles performance counters interrupt >> - */ >> - >> -void pmu_apic_interrupt(struct cpu_user_regs *regs) >> -{ >> - ack_APIC_irq(); >> - vpmu_do_interrupt(regs); >> -} > So this was the only caller of vpmu_do_interrupt(); no new one gets > added in this patch afaics, and I don't recall having seen addition of > another caller in earlier patches. What's the deal? It's in 09/13: +int pmu_nmi_interrupt(struct cpu_user_regs *regs, int cpu) +{ + return vpmu_do_interrupt(regs); +} + -boris