From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [RFC PATCH v3 1/1] kvm: add documentation for the VM introspection subsystem Date: Fri, 15 Sep 2017 16:48:02 +0200 Message-ID: <1083072b-099e-ca94-9bac-cedec3aa6324@redhat.com> References: <20170911153637.30326-1-alazar@bitdefender.com> <20170911153637.30326-2-alazar@bitdefender.com> <3c7028de-7135-bf6e-f468-32ff67ca8f71@redhat.com> <1505480815.5695.25.camel@bitdefender.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Adalbert Lazar , kvm@vger.kernel.org To: =?UTF-8?Q?Mihai_Don=c8=9bu?= Return-path: Received: from mx1.redhat.com ([209.132.183.28]:40520 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751111AbdIOOsG (ORCPT ); Fri, 15 Sep 2017 10:48:06 -0400 In-Reply-To: <1505480815.5695.25.camel@bitdefender.com> Content-Language: en-US Sender: kvm-owner@vger.kernel.org List-ID: On 15/09/2017 15:06, Mihai Donțu wrote: >> Do you need events for reading CRn or MSRs? > > There is another VMI project, Nitro, that uses MSR read events to do a > sort of strace on syscalls and we were thinking on porting that > feature. However, users of that API with which we are in contact, > expressed the intention of moving to a breakpoint based system rather > than trapping for every MSR read. Since we don't have a use case for it > either, we decided to hold off on that unless somebody jumps in and > asks for it. I was thinking of the case where introspection has to modify some MSRs or CRs, and would like the guest kernel to see a fake value. Paolo