From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0/3] KVM: s390: Trace events support. Date: Thu, 26 Jul 2012 14:05:09 +0300 Message-ID: <50112465.3070102@redhat.com> References: <1343056830-45290-1-git-send-email-cornelia.huck@de.ibm.com> <50110F4E.6030106@redhat.com> <20120726124752.00f9fccd@BR9GNB5Z> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120726124752.00f9fccd@BR9GNB5Z> Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Cornelia Huck Cc: Marcelo Tosatti , Christian Borntraeger , Carsten Otte , Alexander Graf , Heiko Carstens , Martin Schwidefsky , KVM , linux-s390 List-ID: On 07/26/2012 01:47 PM, Cornelia Huck wrote: > On Thu, 26 Jul 2012 12:35:10 +0300 > Avi Kivity wrote: > >> On 07/23/2012 06:20 PM, Cornelia Huck wrote: >> > Avi, Marcelo, >> > >> > here's a patch set that introduces trace events for kvm/s390. >> > >> > It's split into two parts: >> > >> > - Trace points for architecture-defined events, like intercepts. >> > This patch calls into the disassembler via the interface provided >> > by the first patch. These trace points show up under events/kvm/. >> > - Trace points for implementation-specific events like interrupt >> > injection. These show up under a new trace system, kvm-s390. >> >> I don't see what's the difference between the two types. Isn't >> interrupt injection architectural? > > I don't think so. The details how we do that might change, it's nothing > dictated by the architecture. > > (It might be argued where interrupt delivery belongs, since parts of it > are architectured, while other parts are made up by us.) > >> >> On x86, the implementation tracepoints are ones that may go away if the >> implementation changes significantly, while the architectural ones will >> not go away unless the architecture is changed. > > That's what I tried to do here as well. > >> In fact creation and >> destruction of vcpus and reset requests are not only architectural, >> they're generic, you may as well add them to the arch independent trace >> code. > > The vpcu creation event also traces interesting information like the > location of our sie control block (in fact, that's the most interesting > information provided by the event). > > The reset request traced is s390 specific (for diag 308 ipl). > >> >> btw - why are vcpu creation and destruction useful events to trace? > > See above - mainly for the control block location. Ok, thanks for the explanations. Applied all. -- error compiling committee.c: too many arguments to function