Commit cd84a42c authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Don't let userspace write to PMCR_EL0.N when the vcpu has EL2 



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.

Reviewed-by: default avatarOliver Upton <oliver.upton@linux.dev>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent b7628c79

arch/arm64/kvm/sys_regs.c

+1 −0
Original line number Diff line number Diff line
@@ -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.nr_pmu_counters = new_n;