Re: AMD Opteron 6276 to Intel Xeon E5645 live migration failure

[Nick Thomas <nick@bytemark.co.uk>]

On 28/02/14 12:57, Paolo Bonzini wrote:
> Il 28/02/2014 13:16, Nick Thomas ha scritto:
>> I'd love to get this working, but I'm a little ignorant on where to
>> begin, or even if it's possible at all. Are these CPUs just too old, or
>> is a fixup missing in qemu (or kvm)?
> 
> It's the latter (in kvm).  Note that for migration to work, especially
> for such different models, you have to disable CPU features that aren't
> present in both models.  In general the way to do this is to add "-cpu".
> 
> I'd start debugging with "-cpu kvm64" on both sides.
> 
> Paolo

Sorry, I forgot to mention - most of my tests have been -cpu
qemu64,-vmx,-svm. I've just re-run the minimal ones with that, and
kvm64, for sanity. Same behaviour.

In the interests of debugging, I guess the next step is to attach gdb to
the destination and find out what's happening around the time the error
messages are pushed out?

I found an earlier thread (
http://www.spinics.net/lists/kvm/msg73478.html ) with a similar flavour
that referenced a "vmxcap" tool - the output of that is here:

Basic VMX Information
  Revision                                 15
  VMCS size                                1024
  VMCS restricted to 32 bit addresses      no
  Dual-monitor support                     yes
  VMCS memory type                         6
  INS/OUTS instruction information         yes
  IA32_VMX_TRUE_*_CTLS support             yes
pin-based controls
  External interrupt exiting               yes
  NMI exiting                              yes
  Virtual NMIs                             yes
  Activate VMX-preemption timer            yes
  Process posted interrupts                no
primary processor-based controls
  Interrupt window exiting                 yes
  Use TSC offsetting                       yes
  HLT exiting                              yes
  INVLPG exiting                           yes
  MWAIT exiting                            yes
  RDPMC exiting                            yes
  RDTSC exiting                            yes
  CR3-load exiting                         default
  CR3-store exiting                        default
  CR8-load exiting                         yes
  CR8-store exiting                        yes
  Use TPR shadow                           yes
  NMI-window exiting                       yes
  MOV-DR exiting                           yes
  Unconditional I/O exiting                yes
  Use I/O bitmaps                          yes
  Monitor trap flag                        yes
  Use MSR bitmaps                          yes
  MONITOR exiting                          yes
  PAUSE exiting                            yes
  Activate secondary control               yes
secondary processor-based controls
  Virtualize APIC accesses                 yes
  Enable EPT                               yes
  Descriptor-table exiting                 yes
  Enable RDTSCP                            yes
  Virtualize x2APIC mode                   yes
  Enable VPID                              yes
  WBINVD exiting                           yes
  Unrestricted guest                       yes
  APIC register emulation                  no
  Virtual interrupt delivery               no
  PAUSE-loop exiting                       yes
  RDRAND exiting                           no
  Enable INVPCID                           no
  Enable VM functions                      no
  VMCS shadowing                           no
  EPT-violation #VE                        no
VM-Exit controls
  Save debug controls                      default
  Host address-space size                  yes
  Load IA32_PERF_GLOBAL_CTRL               yes
  Acknowledge interrupt on exit            yes
  Save IA32_PAT                            yes
  Load IA32_PAT                            yes
  Save IA32_EFER                           yes
  Load IA32_EFER                           yes
  Save VMX-preemption timer value          yes
VM-Entry controls
  Load debug controls                      default
  IA-64 mode guest                         yes
  Entry to SMM                             yes
  Deactivate dual-monitor treatment        yes
  Load IA32_PERF_GLOBAL_CTRL               yes
  Load IA32_PAT                            yes
  Load IA32_EFER                           yes
Miscellaneous data
  VMX-preemption timer scale (log2)        7
  Store EFER.LMA into IA-32e mode guest control yes
  HLT activity state                       yes
  Shutdown activity state                  yes
  Wait-for-SIPI activity state             yes
  IA32_SMBASE support                      no
  Number of CR3-target values              4
  MSR-load/store count recommenation       0
  IA32_SMM_MONITOR_CTL[2] can be set to 1  no
  VMWRITE to VM-exit information fields    no
  MSEG revision identifier                 0
VPID and EPT capabilities
  Execute-only EPT translations            yes
  Page-walk length 4                       yes
  Paging-structure memory type UC          yes
  Paging-structure memory type WB          yes
  2MB EPT pages                            yes
  1GB EPT pages                            yes
  INVEPT supported                         yes
  EPT accessed and dirty flags             no
  Single-context INVEPT                    yes
  All-context INVEPT                       yes
  INVVPID supported                        yes
  Individual-address INVVPID               yes
  Single-context INVVPID                   yes
  All-context INVVPID                      yes
  Single-context-retaining-globals INVVPID yes
VM Functions
  EPTP Switching                           no


Mostly Greek, but I assume one of the things labeled "no" is the source
of my woes?

/Nick