From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC] para virt interface of perf to support kvm guest os statistics collection in guest os Date: Thu, 10 Jun 2010 06:06:06 +0300 Message-ID: <4C10569E.6020503@redhat.com> References: <1276054214.2096.383.camel@ymzhang.sh.intel.com> <4C0F51DD.3080200@redhat.com> <1276075280.2096.427.camel@ymzhang.sh.intel.com> <4C0F61D3.9000402@redhat.com> <1276136493.2096.462.camel@ymzhang.sh.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: LKML , kvm@vger.kernel.org, Ingo Molnar , Fr??d??ric Weisbecker , Arnaldo Carvalho de Melo , Cyrill Gorcunov , Lin Ming , Sheng Yang , Marcelo Tosatti , oerg Roedel , Jes Sorensen , Gleb Natapov , Zachary Amsden , zhiteng.huang@intel.com, tim.c.chen@intel.com, Peter Zijlstra To: "Zhang, Yanmin" Return-path: In-Reply-To: <1276136493.2096.462.camel@ymzhang.sh.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 06/10/2010 05:21 AM, Zhang, Yanmin wrote: > >> I see. So put it in a union. Or perhaps not even in a union - what if >> a kvm guest is also acting as a kvm host? >> > My patch has consideration on it. I compiled kernel with host and guest support > at the same time. The accessing to perf_event->shadow is really under specific > scenarios, or they are just in specific functions. These functions are called > just bu host kernel , or just by guest kernel. > But a kernel can be both guest and host at the same time. Currently this only works on AMD, but there was some work to bring it to Intel as well. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.