From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org
Cc: Joey Gouly <joey.gouly@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Oliver Upton <oliver.upton@linux.dev>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH v2 4/6] KVM: arm64: Don't let userspace write to PMCR_EL0.N when the vcpu has EL2
Date: Wed, 9 Apr 2025 17:01:04 +0100 [thread overview]
Message-ID: <20250409160106.6445-5-maz@kernel.org> (raw)
In-Reply-To: <20250409160106.6445-1-maz@kernel.org>
Now that userspace can provide its limit for hte maximum number of
counters, prevent it from writing to PMCR_EL0.N, as the value should
be derived from MDCR_EL2.HPMN in that case.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/sys_regs.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 73d68ea37ac21..00b5396492d51 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1216,6 +1216,7 @@ static int set_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r,
* with the existing KVM behavior.
*/
if (!kvm_vm_has_ran_once(kvm) &&
+ !vcpu_has_nv(vcpu) &&
new_n <= kvm_arm_pmu_get_max_counters(kvm))
kvm->arch.pmcr_n = new_n;
--
2.39.2
next prev parent reply other threads:[~2025-04-09 16:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-09 16:01 [PATCH v2 0/6] KVM: arm64: EL2 PMU handling fixes Marc Zyngier
2025-04-09 16:01 ` [PATCH v2 1/6] KVM: arm64: Fix MDCR_EL2.HPMN reset value Marc Zyngier
2025-04-09 20:21 ` Oliver Upton
2025-04-10 10:54 ` Marc Zyngier
2025-04-10 17:38 ` Oliver Upton
2025-04-09 16:01 ` [PATCH v2 2/6] KVM: arm64: Contextualise the handling of PMCR_EL0.P writes Marc Zyngier
2025-04-09 16:01 ` [PATCH v2 3/6] KVM: arm64: Allow userspace to limit the number of PMU counters for EL2 VMs Marc Zyngier
2025-04-09 20:25 ` Oliver Upton
2025-04-09 16:01 ` Marc Zyngier [this message]
2025-04-09 16:01 ` [PATCH v2 5/6] KVM: arm64: Handle out-of-bound write to HDCR_EL2.HPMN Marc Zyngier
2025-04-09 20:29 ` Oliver Upton
2025-04-09 16:01 ` [PATCH v2 6/6] KVM: arm64: Let kvm_vcpu_read_pmcr() return an EL-dependent value for PMCR_EL0.N Marc Zyngier
2025-04-09 20:31 ` [PATCH v2 0/6] KVM: arm64: EL2 PMU handling fixes Oliver Upton
2025-04-11 12:00 ` Marc Zyngier
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