From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 0/9] Add support for nested SVM (kernel) v3 Date: Fri, 19 Sep 2008 17:56:52 +0200 Message-ID: <20080919155652.GQ24392@amd.com> References: <1221658886-14109-1-git-send-email-agraf@suse.de> <20080919143600.GO24392@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: kvm@vger.kernel.org, joro@8bytes.org, anthony@codemonkey.ws, avi@qumranet.com To: Alexander Graf Return-path: Received: from outbound-wa4.frontbridge.com ([216.32.181.16]:52685 "EHLO WA4EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752949AbYISP5F (ORCPT ); Fri, 19 Sep 2008 11:57:05 -0400 Content-Disposition: inline In-Reply-To: <20080919143600.GO24392@amd.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Sep 19, 2008 at 04:36:00PM +0200, Joerg Roedel wrote: > On Wed, Sep 17, 2008 at 03:41:17PM +0200, Alexander Graf wrote: > > To be usable, this patchset requires the two simple changes in the userspace > > part, that I sent to the list with the first version. > > > > Thanks for reviewing! > > Ok, with the patch attached applied on-top of your patches I got a > recent KVM running inside KVM. And it doesn't feel very slow :-) > I will do some benchmarks in the next days to get real numbers. The > patches look good so far. > But I think for now we should disable the feature by default and allow > enabling it from userspace until we are sure we don't introduce any > security hole and don't destroy migration with it. We can add a > -nested-virt parameter to qemu to enable it for the guest then. > Another thing missing is the SVM feature CPUID function. It is used to > find out the number of ASIDs available. But this is a minor issue as > long as we only run KVM inside KVM. Ok, further testing showed two issues so far: - guest timing seems not to work, the printk timing information in ubuntu stay at 0.00000 all the time - smp for the second level guest does not work, it crashes also the first level guest Joerg -- | AMD Saxony Limited Liability Company & Co. KG Operating | Wilschdorfer Landstr. 101, 01109 Dresden, Germany System | Register Court Dresden: HRA 4896 Research | General Partner authorized to represent: Center | AMD Saxony LLC (Wilmington, Delaware, US) | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy