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authorMarc Zyngier <maz@kernel.org>2021-09-19 14:09:49 +0100
committerMarc Zyngier <maz@kernel.org>2021-09-20 12:43:34 +0100
commite840f42a49925707fca90e6c7a4095118fdb8c4d (patch)
tree127985ebfa09474234a135530d24021f0d3e850b /drivers/perf
parenta49b50a3c1c3226d26e1dd11e8b763f27e477623 (diff)
KVM: arm64: Fix PMU probe ordering
Russell reported that since 5.13, KVM's probing of the PMU has started to fail on his HW. As it turns out, there is an implicit ordering dependency between the architectural PMU probing code and and KVM's own probing. If, due to probe ordering reasons, KVM probes before the PMU driver, it will fail to detect the PMU and prevent it from being advertised to guests as well as the VMM. Obviously, this is one probing too many, and we should be able to deal with any ordering. Add a callback from the PMU code into KVM to advertise the registration of a host CPU PMU, allowing for any probing order. Fixes: 5421db1be3b1 ("KVM: arm64: Divorce the perf code from oprofile helpers") Reported-by: "Russell King (Oracle)" <linux@armlinux.org.uk> Tested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/YUYRKVflRtUytzy5@shell.armlinux.org.uk Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/perf')
-rw-r--r--drivers/perf/arm_pmu.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 3cbc3baf087f..295cc7952d0e 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -952,6 +952,8 @@ int armpmu_register(struct arm_pmu *pmu)
pmu->name, pmu->num_events,
has_nmi ? ", using NMIs" : "");
+ kvm_host_pmu_init(pmu);
+
return 0;
out_destroy: