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")
Cc: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
---
 arch/arm64/kvm/sys_regs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 76c2f0da821f..c20bd6f21e60 100644
--- 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);
-- 
2.43.0

On Wed, 09 Jul 2025 10:38:07 +0100, Ben Horgan wrote:
> 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.
> 
> 

Applied to fixes, thanks!

I have dropped the Cc: stable, as ths bug only exists in 6.16, and we
are not backporting anything related to NV to previous kernel versions.

[1/2] KVM: arm64: Fix enforcement of upper bound on MDCR_EL2.HPMN
      commit: 2265c08ec393ef1f5ef5019add0ab1e3a7ee0b79

Cheers,

	M.
-- 
Without deviation from the norm, progress is not possible.