Messages in this thread | | | Date | Thu, 03 Jan 2019 15:22:07 +0800 | From | Wei Wang <> | Subject | Re: [PATCH v4 04/10] KVM/x86: intel_pmu_lbr_enable |
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On 01/03/2019 07:26 AM, Jim Mattson wrote: > On Wed, Dec 26, 2018 at 2:01 AM Wei Wang <wei.w.wang@intel.com> wrote: >> The lbr stack is architecturally specific, for example, SKX has 32 lbr >> stack entries while HSW has 16 entries, so a HSW guest running on a SKX >> machine may not get accurate perf results. Currently, we forbid the >> guest lbr enabling when the guest and host see different lbr stack >> entries. > How do you handle live migration?
This feature is gated by the QEMU "lbr=true" option. So if the lbr fails to work on the destination machine, the destination side QEMU wouldn't be able to boot, and migration will not happen.
Best, Wei
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