From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: Re: [PATCH v2 1/1] target-i386: Fix default Hypervisor level for hypervisor-vendor=kvm. Date: Fri, 21 Sep 2012 17:49:20 -0300 Message-ID: <20120921204920.GD3983@otherpad.lan.raisama.net> References: <1348171587-23725-1-git-send-email-Don@CloudSwitch.com> <1348171587-23725-2-git-send-email-Don@CloudSwitch.com> <20120921141829.GC3983@otherpad.lan.raisama.net> <505CCD92.5080300@CloudSwitch.Com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: qemu-devel@nongnu.org, imammedo@redhat.com, kvm@vger.kernel.org To: Don Slutz Return-path: Received: from mx1.redhat.com ([209.132.183.28]:11066 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757856Ab2IUUsR (ORCPT ); Fri, 21 Sep 2012 16:48:17 -0400 Content-Disposition: inline In-Reply-To: <505CCD92.5080300@CloudSwitch.Com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Sep 21, 2012 at 04:26:58PM -0400, Don Slutz wrote: > On 09/21/12 10:18, Eduardo Habkost wrote: > >On Thu, Sep 20, 2012 at 04:06:27PM -0400, Don Slutz wrote: > >> From http://lkml.indiana.edu/hypermail/linux/kernel/1205.0/00100.html > >>EAX should be KVM_CPUID_FEATURES (0x40000001) not 0. > >> > >>Added hypervisor-vendor=kvm0 to get the older CPUID result. kvm1 selects the newer one. > >Why not just make "hypervisor-vendor=kvm" control only the hypervisor > >vendor string, and support something like "kvm-hypervisor-level=0" to > >restore the old cpuid_hv_level=0 behavior? > -cpu host,hypervisor-vendor=kvm,hypervisor-level=0 > > Does this. Good. :-) > > > >This is similar to the kvmclock case: it would allow us to make > >"hypervisor-vendor=kvm" use saner values as default, but letting old > >machine-types to override it for compatibility if required. > Right now since I am using env->cpuid_hv_level == 0 as a flag. This > means that: > > -cpu host,hypervisor-level=0,hypervisor-vendor=kvm > > -cpu host,hypervisor-vendor=kvm,hypervisor-level=0 > > end up with different CPUID data (Which I do not like). I will fix this in the next round. Right. This has to be fixed. > > Did you want me to drop kvm0 and kvm1? Yes, if level is already configurable using the hypervisor-level property, I don't see the need for kvm0 and kvm1. If you make kvm_arch_init_vcpu() actually use those fields, you will end up implementing what's required to allow migration compatibility to be kept (the only thing missing is to make the CPU class a child of DeviceState, and add hypervisor-level=0 to the existing machine-types). :-) -- Eduardo