The patch below does not apply to the 4.19-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.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x 54bbee190d42166209185d89070c58a343bf514b # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024120223-stunner-letter-9d09@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 54bbee190d42166209185d89070c58a343bf514b Mon Sep 17 00:00:00 2001 From: Raghavendra Rao Ananta rananta@google.com Date: Tue, 19 Nov 2024 16:52:29 -0800 Subject: [PATCH] KVM: arm64: Ignore PMCNTENSET_EL0 while checking for overflow status
DDI0487K.a D13.3.1 describes the PMU overflow condition, which evaluates to true if any counter's global enable (PMCR_EL0.E), overflow flag (PMOVSSET_EL0[n]), and interrupt enable (PMINTENSET_EL1[n]) are all 1. Of note, this does not require a counter to be enabled (i.e. PMCNTENSET_EL0[n] = 1) to generate an overflow.
Align kvm_pmu_overflow_status() with the reality of the architecture and stop using PMCNTENSET_EL0 as part of the overflow condition. The bug was discovered while running an SBSA PMU test [*], which only sets PMCR.E, PMOVSSET<0>, PMINTENSET<0>, and expects an overflow interrupt.
Cc: stable@vger.kernel.org Fixes: 76d883c4e640 ("arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register") Link: https://github.com/ARM-software/sbsa-acs/blob/master/test_pool/pmu/operating... Signed-off-by: Raghavendra Rao Ananta rananta@google.com [ oliver: massaged changelog ] Reviewed-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20241120005230.2335682-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton oliver.upton@linux.dev
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 8ad62284fa23..3855cc9d0ca5 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -381,7 +381,6 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
if ((kvm_vcpu_read_pmcr(vcpu) & ARMV8_PMU_PMCR_E)) { reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0); - reg &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); reg &= __vcpu_sys_reg(vcpu, PMINTENSET_EL1); }