From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liuyingdong Subject: Question about XEN Hypervisor MSR capability exposion to VMs Date: Sat, 31 Oct 2015 10:53:54 +0800 Message-ID: <56342D42.1040304@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: kevin.tian@intel.com, wei.liu2@citrix.com, andrew.cooper3@citrix.com, "Huangpeng (Peter)" , dietmar.hahn@ts.fujitsu.com, "huangzhichao@huawei.com >> Huangzhichao" , boris.ostrovsky@oracle.com List-Id: xen-devel@lists.xenproject.org Hi All We encountered a blue screen problem when live migrate Win8.1/Win2012R2 64bit VM from V3 processor to non-V3 processor sandbox, KVM does not has this problem. After looking into the MSR capabilities, we found XEN hypervisor exposed bit 39 and bit 18 to the VM, from Intel manual bit 39 refers to reserve bit and should not be set, bit 18 refers to MWAIT/MONITOR capability, from my understanding it should not exposed to the VM too. BTW, KVM does not expose bit 18/39 to the VM. Below is the boot message: (XEN) read msr: ecx=c0000083, msr_value=0xfffff80028ddf240 (XEN) read msr: ecx=1a0, msr_value=0x4000801889 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (XEN) write msr:msr=40000071, msr_value=0x10000000000082f (XEN) write msr:msr=40000070, msr_value=0x0 (XEN) write msr:msr=40000071, msr_value=0x20000000000082f (XEN) write msr:msr=40000070, msr_value=0x0 (XEN) read msr: ecx=17, msr_value=0x0 (XEN) write msr:msr=8b, msr_value=0x0 (XEN) read msr: ecx=8b, msr_value=0x2d00000000