Commit 2265c08e authored by Ben Horgan's avatar Ben Horgan Committed by Marc Zyngier
Browse files

KVM: arm64: Fix enforcement of upper bound on MDCR_EL2.HPMN 



Previously, u64_replace_bits() was used to no effect as the return value
was ignored. Convert to u64p_replace_bits() so the value is updated in
place.

Reviewed-by: default avatarZenghui Yu <yuzenghui@huawei.com>
Signed-off-by: default avatarBen Horgan <ben.horgan@arm.com>
Fixes: efff9dd2 ("KVM: arm64: Handle out-of-bound write to MDCR_EL2.HPMN")
Link: https://lore.kernel.org/r/20250709093808.920284-2-ben.horgan@arm.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 42ce4325

arch/arm64/kvm/sys_regs.c

+1 −1
Original line number Diff line number Diff line
@@ -2624,7 +2624,7 @@ static bool access_mdcr(struct kvm_vcpu *vcpu, 
	 */

	if (hpmn > vcpu->kvm->arch.nr_pmu_counters) {

		hpmn = vcpu->kvm->arch.nr_pmu_counters;

		u64_replace_bits(val, hpmn, MDCR_EL2_HPMN);

		u64p_replace_bits(&val, hpmn, MDCR_EL2_HPMN);

	}



	__vcpu_assign_sys_reg(vcpu, MDCR_EL2, val);