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 16:36:00 +0200 Message-ID: <20080919143600.GO24392@amd.com> References: <1221658886-14109-1-git-send-email-agraf@suse.de> 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]:22514 "EHLO WA4EHSOBE001.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751016AbYISOgV (ORCPT ); Fri, 19 Sep 2008 10:36:21 -0400 Content-Disposition: inline In-Reply-To: <1221658886-14109-1-git-send-email-agraf@suse.de> Sender: kvm-owner@vger.kernel.org List-ID: 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. 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