075becedce
[ Upstream commit 3317c26a4b413b41364f2c4b83c778c6aba1576d ]
The Architecture LBR does not have MSR_LBR_TOS (0x000001c9).
In a guest that should support Architecture LBR, check_msr()
will be a non-related check for the architecture MSR 0x0
(IA32_P5_MC_ADDR) that is also not supported by KVM.
The failure will cause x86_pmu.lbr_nr = 0, thereby preventing
the initialization of the guest Arch LBR. Fix it by avoiding
this extraneous check in intel_pmu_init() for Arch LBR.
Fixes: 47125db27e47 ("perf/x86/intel/lbr: Support Architectural LBR")
Signed-off-by: Like Xu <like.xu@linux.intel.com>
[peterz: simpler still]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210430052247.3079672-1-like.xu@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>