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: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
Fixes: efff9dd2fee7 ("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: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 76c2f0da821f8c992cc4a706555dc5b099438316..c20bd6f21e608af0cefee6cffe3d17bbf5af5b2a 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -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);