FAILED: patch "[PATCH] KVM: arm64: pmu: Don't increment SW_INCR if PMCR.E is unset" failed to apply to 4.9-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3837407c1aa1101ed5e214c7d6041e7a23335c6e Mon Sep 17 00:00:00 2001
From: Eric Auger <eric.auger@redhat.com>
Date: Fri, 24 Jan 2020 15:25:32 +0100
Subject: [PATCH] KVM: arm64: pmu: Don't increment SW_INCR if PMCR.E is unset

The specification says PMSWINC increments PMEVCNTR<n>_EL1 by 1
if PMEVCNTR<n>_EL0 is enabled and configured to count SW_INCR.

For PMEVCNTR<n>_EL0 to be enabled, we need both PMCNTENSET to
be set for the corresponding event counter but we also need
the PMCR.E bit to be set.

Fixes: 7a0adc7064b8 ("arm64: KVM: Add access handler for PMSWINC register")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200124142535.29386-2-eric.auger@redhat.com

diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 8731dfeced8b..c3f8b059881e 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -486,6 +486,9 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
 	if (val == 0)
 		return;
 
+	if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E))
+		return;
+
 	enable = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
 	for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) {
 		if (!(val & BIT(i)))