From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH V4 2/4] KVM: x86/vPMU: Create vPMU interface for VMX and SVM Date: Wed, 10 Jun 2015 20:05:31 +0200 Message-ID: <20150610180531.GD20384@8bytes.org> References: <1433481616-24884-1-git-send-email-wei@redhat.com> <1433481616-24884-3-git-send-email-wei@redhat.com> <20150610101212.GB20384@8bytes.org> <55786928.1000909@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org, pbonzini@redhat.com, gleb@kernel.org, rkrcmar@redhat.com To: Wei Huang Return-path: Received: from 8bytes.org ([81.169.241.247]:33779 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003AbbFJSFc (ORCPT ); Wed, 10 Jun 2015 14:05:32 -0400 Content-Disposition: inline In-Reply-To: <55786928.1000909@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Jun 10, 2015 at 11:43:20AM -0500, Wei Huang wrote: > On 06/10/2015 05:12 AM, Joerg Roedel wrote: > > On Fri, Jun 05, 2015 at 01:20:14AM -0400, Wei Huang wrote: > >> + > >> + struct kvm_pmu_ops *(*get_pmu_ops)(void); > > > > Can't you just set kvm_pmu_ops in svm.c and vmx.c and save this > > call-back? Besides that the patch looks good. > Hi Joerg, > > Thanks for your review. How about setting up kvm_pmu_ops in > .hardware_setup function of VMX and SVM? More specifically: > > 1) EXPORT_SYMBOL_GPL(kvm_pmu_ops) from pmu.c file; > 2) In vmx.c, set "kvm_pmu_ops = &intel_pmu_ops" in hardware_setup(); > 3) In svm.c, set "kvm_pmu_ops = &amd_pmu_ops" in svm_hardware_setup(). > > With that, we can get rid of the call-back. Okay, just had a look at how this works with kvm_x86_ops, because my suggestion needs the EXPORT_SYMBOL_GPL(kvm_pmu_ops), which is better also avoided. So how about putting the pmu-ops directly into the kvm_x86_ops as a (const) member, or alternativly as an additional parameter to kvm_init? This still saves us the access functions. Joerg