Re: [Qemu-devel] [Bug Report] vm paused after succeeding to migrate
> -邮件原件- > 发件人: Dr. David Alan Gilbert [mailto:dgilb...@redhat.com] > 发送时间: 2018年4月12日 20:37 > 收件人: linzhecheng ; pbonz...@redhat.com > 抄送: qemu-devel@nongnu.org; wangxin (U) ; > Zhoujian (jay) ; quint...@redhat.com > 主题: Re: [Qemu-devel] [Bug Report] vm paused after succeeding to migrate > > * linzhecheng (linzhech...@huawei.com) wrote: > > Hi, all > > I encounterd a bug when I try to migrate a windows vm. > > > > Enviroment information: > > host A: cpu E5620(model WestmereEP without flag xsave) host B: cpu > > E5-2643(model SandyBridgeEP with xsave) > > > > The reproduce steps is : > > 1. Start a windows 2008 vm with -cpu host(which means host-passthrough). > > 2. Migrate the vm to host B when cr4.OSXSAVE=0 (successfully). > > 3. Vm runs on host B for a while so that cr4.OSXSAVE changes to 1. > > 4. Then migrate the vm to host A (successfully), but vm was paused, and > qemu printed log as followed: > > Remember that migrating using -cpu host across different CPU models is NOT > expected to work. > > > KVM: entry failed, hardware error 0x8021 > > > > If you're running a guest on an Intel machine without unrestricted > > mode support, the failure can be most likely due to the guest entering > > an invalid state for Intel VT. For example, the guest maybe running in > > big real mode which is not supported on less recent Intel processors. > > > > EAX=019b3bb0 EBX=01a3ae80 ECX=01a61ce8 EDX= > > ESI=01a62000 EDI= EBP= ESP=01718b20 > > EIP=0185d982 EFL=0286 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES > > = 9300 CS =f000 9b00 > > SS = 9300 DS = > > 9300 FS = 9300 GS = > > 9300 > > LDT= 8200 > > TR = 8b00 > > GDT= > > IDT= > > CR0=6010 CR2= CR3= CR4= > > DR0= DR1= DR2= > > DR3= > > DR6=0ff0 DR7=0400 > > EFER= > > Code=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> > > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > 00 00 00 00 00 00 > > > > I have found that problem happened when kvm_put_sregs returns err - > 22(called by kvm_arch_put_registers(qemu)). > > Because kvm_arch_vcpu_ioctl_set_sregs(kvm-mod) checked that > guest_cpuid_has no X86_FEATURE_XSAVE but cr4.OSXSAVE=1. > > So should we cancel migration when kvm_arch_put_registers returns error? > > It would seem good if we can make the migration fail there rather than hitting > that KVM error. > It looks like we need to do a bit of plumbing to convert the places that call > it to > return a bool rather than void. I think we should return a int value of run_on_cpu which callback run_on_cpu_func, but run_on_cpu_func is the prototype of many functions, Is it overkill? > > Dave > > -- > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
Re: [Qemu-devel] [Bug Report] vm paused after succeeding to migrate
* linzhecheng (linzhech...@huawei.com) wrote: > Hi, all > I encounterd a bug when I try to migrate a windows vm. > > Enviroment information: > host A: cpu E5620(model WestmereEP without flag xsave) > host B: cpu E5-2643(model SandyBridgeEP with xsave) > > The reproduce steps is : > 1. Start a windows 2008 vm with -cpu host(which means host-passthrough). > 2. Migrate the vm to host B when cr4.OSXSAVE=0 (successfully). > 3. Vm runs on host B for a while so that cr4.OSXSAVE changes to 1. > 4. Then migrate the vm to host A (successfully), but vm was paused, and qemu > printed log as followed: Remember that migrating using -cpu host across different CPU models is NOT expected to work. > KVM: entry failed, hardware error 0x8021 > > If you're running a guest on an Intel machine without unrestricted mode > support, the failure can be most likely due to the guest entering an invalid > state for Intel VT. For example, the guest maybe running in big real mode > which is not supported on less recent Intel processors. > > EAX=019b3bb0 EBX=01a3ae80 ECX=01a61ce8 EDX= > ESI=01a62000 EDI= EBP= ESP=01718b20 > EIP=0185d982 EFL=0286 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 > ES = 9300 > CS =f000 9b00 > SS = 9300 > DS = 9300 > FS = 9300 > GS = 9300 > LDT= 8200 > TR = 8b00 > GDT= > IDT= > CR0=6010 CR2= CR3= CR4= > DR0= DR1= DR2= > DR3= > DR6=0ff0 DR7=0400 > EFER= > Code=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 > > I have found that problem happened when kvm_put_sregs returns err -22(called > by kvm_arch_put_registers(qemu)). > Because kvm_arch_vcpu_ioctl_set_sregs(kvm-mod) checked that guest_cpuid_has > no X86_FEATURE_XSAVE but cr4.OSXSAVE=1. > So should we cancel migration when kvm_arch_put_registers returns error? It would seem good if we can make the migration fail there rather than hitting that KVM error. It looks like we need to do a bit of plumbing to convert the places that call it to return a bool rather than void. Dave -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
[Qemu-devel] [Bug Report] vm paused after succeeding to migrate
Hi, all I encounterd a bug when I try to migrate a windows vm. Enviroment information: host A: cpu E5620(model WestmereEP without flag xsave) host B: cpu E5-2643(model SandyBridgeEP with xsave) The reproduce steps is : 1. Start a windows 2008 vm with -cpu host(which means host-passthrough). 2. Migrate the vm to host B when cr4.OSXSAVE=0 (successfully). 3. Vm runs on host B for a while so that cr4.OSXSAVE changes to 1. 4. Then migrate the vm to host A (successfully), but vm was paused, and qemu printed log as followed: KVM: entry failed, hardware error 0x8021 If you're running a guest on an Intel machine without unrestricted mode support, the failure can be most likely due to the guest entering an invalid state for Intel VT. For example, the guest maybe running in big real mode which is not supported on less recent Intel processors. EAX=019b3bb0 EBX=01a3ae80 ECX=01a61ce8 EDX= ESI=01a62000 EDI= EBP= ESP=01718b20 EIP=0185d982 EFL=0286 [--S--P-] CPL=0 II=0 A20=1 SMM=0 HLT=0 ES = 9300 CS =f000 9b00 SS = 9300 DS = 9300 FS = 9300 GS = 9300 LDT= 8200 TR = 8b00 GDT= IDT= CR0=6010 CR2= CR3= CR4= DR0= DR1= DR2= DR3= DR6=0ff0 DR7=0400 EFER= Code=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 I have found that problem happened when kvm_put_sregs returns err -22(called by kvm_arch_put_registers(qemu)). Because kvm_arch_vcpu_ioctl_set_sregs(kvm-mod) checked that guest_cpuid_has no X86_FEATURE_XSAVE but cr4.OSXSAVE=1. So should we cancel migration when kvm_arch_put_registers returns error?
