From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Young Subject: Re: unhandled wrmsr Date: Thu, 3 Jun 2010 10:23:15 +0800 Message-ID: References: <4C065257.5010809@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "kvm@vger.kernel.org" To: Andre Przywara Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:54824 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933577Ab0FCCXQ convert rfc822-to-8bit (ORCPT ); Wed, 2 Jun 2010 22:23:16 -0400 Received: by vws11 with SMTP id 11so3399916vws.19 for ; Wed, 02 Jun 2010 19:23:15 -0700 (PDT) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Jun 3, 2010 at 9:34 AM, Dave Young = wrote: > On Wed, Jun 2, 2010 at 8:45 PM, Andre Przywara wrote: >> Dave Young wrote: >>> >>> Hi, >>> >>> With today's git version (qemu-kvm), I got following message in ker= nel >>> dmesg >>> >>> [168344.215605] kvm: 27289: cpu0 unhandled wrmsr: 0x198 data 0 >> >> Are you sure about that? > > Sure > > 0x198 is an Intel architectural perfmon MSR and it >> is read-only. The Linux kernel source I grep'ed obeys this and does = only >> rdmsr. >> You can work around this by changing the error to a warning with: >> # modprobe kvm ignore_msrs=3D1 > > with this param, appear following warning: > kvm: 28520: cpu0 ignored wrmsr: 0x198 data 0 > >> >> I'd like to see more details about the guest Linux kernel, at least = the >> version you used to see why there is a wrmsr on this address. Best i= s you >> provide the kernel (just the vmlinuz file) somewhere so that we can >> reproduce this. Also the qemu-kvm command line would be interesting. > > Actually I tried different guest image, recreate this problem is easy= =2E > > one of them is slackware 13.0 kernel version 2.6.29.6, you can downlo= ad from: > http://www.slackware.at/data/slackware64-13.0/kernels/huge.s/ > > kvm cmdline: > qemu-system-x86_64 -net nic -net tap,ifname=3Dtap0,script=3Dno slack6= 4.img > >> >> Regards, >> Andre. >> >>> >>> bash-3.1$ /home/dave/tmp/qemu-system-x86_64 --version >>> QEMU emulator version 0.12.50 (qemu-kvm-devel), Copyright (c) >>> 2003-2008 Fabrice Bellard Another problem with this build is I can not boot from virtio-blk, cmdl= ine: qemu-system-x86_64 -boot c -drive file=3Dslack64.img,if-virtio,boot=3Do= n qemu just complain about: Could not read the boot disk Anything missing by me? >>> >>> >>> bash-3.1$ uname -a >>> Linux darkstar 2.6.35-rc1 #35 SMP Mon May 31 16:50:15 CST 2010 x86_= 64 >>> Intel(R) Core(TM)2 Duo CPU =C2=A0 =C2=A0 E7500 =C2=A0@ 2.93GHz Genu= ineIntel GNU/Linux >>> >>> host distribution is slackware64-13.0 >>> >>> 0.12.3 works well >>> >>> BTW the guest is a tiny core linux image >>> >> >> -- >> Andre Przywara >> AMD-Operating System Research Center (OSRC), Dresden, Germany >> Tel: +49 351 448-3567-12 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at =C2=A0http://vger.kernel.org/majordomo-info.h= tml >> > > > > -- > Regards > dave > --=20 Regards dave