On Thu, Mar 22, 2007 at 09:38:12AM +0200, Avi Kivity wrote: > Joerg Roedel wrote: > >From: Joerg Roedel <[EMAIL PROTECTED]> > > > >This patch forbids the guest to execute monitor/mwait instructions on > >SVM. This is necessary because the guest can execute these instructions > >if they are available even if the kvm cpuid doesn't report its > >existence. > > > > > > You're intercepting the instructions unconditionally. What about the case > where cpuid does > report monitor/mwait support? The guest can legitimately use them then.
I prepared a patch for QEmu to handle this but finally not submitted it because QEmu does not set the Monitor bit anyway. But you are right. It is possible for userspace to set the Montior bit and the guest won't be able to use it. I think an architecture dependent cpuid mask feature in the kernel would solve this problem. I'll prepare a patch for that. Joerg -- Joerg Roedel Operating System Research Center AMD Saxony LLC & Co. KG ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
