forked from luck/tmp_suning_uos_patched
ab112cc573
[ Upstream commit 4b2f1e59229b9da319d358828cdfa4ddbc140769 ]
The only stepping of Broadwell Xeon parts is stepping 1. Fix the
relevant isolation_ucodes[] entry, which previously enumerated
stepping 2.
Although the original commit was characterized as an optimization, it
is also a workaround for a correctness issue.
If a PMI arrives between kvm's call to perf_guest_get_msrs() and the
subsequent VM-entry, a stale value for the IA32_PEBS_ENABLE MSR may be
restored at the next VM-exit. This is because, unbeknownst to kvm, PMI
throttling may clear bits in the IA32_PEBS_ENABLE MSR. CPUs with "PEBS
isolation" don't suffer from this issue, because perf_guest_get_msrs()
doesn't report the IA32_PEBS_ENABLE value.
Fixes:
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||
|---|---|---|
| .. | ||
| amd | ||
| intel | ||
| zhaoxin | ||
| core.c | ||
| Kconfig | ||
| Makefile | ||
| msr.c | ||
| perf_event.h | ||
| probe.c | ||
| probe.h | ||
| rapl.c | ||