From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34455) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YB2iD-0001lZ-HW for qemu-devel@nongnu.org; Tue, 13 Jan 2015 09:44:54 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YB2iA-0004An-5C for qemu-devel@nongnu.org; Tue, 13 Jan 2015 09:44:53 -0500 Received: from david.siemens.de ([192.35.17.14]:32908) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YB2i9-0004AQ-PO for qemu-devel@nongnu.org; Tue, 13 Jan 2015 09:44:50 -0500 Message-ID: <54B52F5D.4060801@siemens.com> Date: Tue, 13 Jan 2015 15:44:45 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <54B52105.60009@redhat.com> In-Reply-To: <54B52105.60009@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] nested VMX with IA32_FEATURE_CONTROL MSR(addr: 0x3a) value of ZERO List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , Huaicheng Li , qemu-devel@nongnu.org On 2015-01-13 14:43, Paolo Bonzini wrote: > > > On 13/01/2015 14:19, Huaicheng Li wrote: >> Hi, all >> >> I have a Linux 3.8 kernel (host) and run QEMU 1.5.3 on it. I want to >> test another hypervisor software in qemu so I enabled KVM's nested VMX >> function(by passing "nested=1" parameter to the kvm module) and then >> started a guest machine. In the guest, I could see the "vmx" instruction >> set by reading /proc/cpuinfo and the kvm module can be correctly >> inserted. But when I read the value of the IA32_FEATURE_CONTROL MSR >> using msr-tools, it showed _0_, but the correct value should be _5_, >> since bit 0(virtualization lock bit) and bit 2 of that MSR must be set >> to enable the virtualization functionality. But in my vmware workstation >> guest with nested virtualization enabled, the value of that MSR is, >> indeed, _5_ as well as in the physical machine (of course). Here, I want >> to ask >> >> * Am I missing anything in my operation to totally enable the nested >> virtualization function ?? (I googled a lot and it seemed there were no >> additional steps) > > You have an old kernel. IA32_FEATURE_CONTROL MSR emulation was added in > 3.12. ...and lots of other nvmx bugs were fixed afterwards. If you don't want to debug KVM but your hypervisor, use the latest stable kernel, currently 3.18.2. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux