[PATCH] KVM: arm64: Fix misuse of KVM_ARM_VCPU_POWER_OFF bit index

[Oliver Upton <oliver.upton@linux.dev>]

KVM_ARM_VCPU_POWER_OFF is as bit index, _not_ a literal bitmask.
Nonetheless, commit e3c1c0cae31e ("KVM: arm64: Relax invariance
of KVM_ARM_VCPU_POWER_OFF") started using it that way, meaning that
powering off a vCPU with the KVM_ARM_VCPU_INIT ioctl is completely
broken.

Fix it by using a shifted bit for the bitwise operations instead.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: e3c1c0cae31e ("KVM: arm64: Relax invariance of KVM_ARM_VCPU_POWER_OFF")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/arm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 80ca7ec269dc..7d20bfd77e1c 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1250,8 +1250,8 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
 	 * reflecting it in the finalized feature set, thus limiting its scope
 	 * to a single KVM_ARM_VCPU_INIT call.
 	 */
-	if (init->features[0] & KVM_ARM_VCPU_POWER_OFF) {
-		init->features[0] &= ~KVM_ARM_VCPU_POWER_OFF;
+	if (init->features[0] & (1UL << KVM_ARM_VCPU_POWER_OFF)) {
+		init->features[0] &= ~(1UL << KVM_ARM_VCPU_POWER_OFF);
 		power_off = true;
 	}
 

base-commit: 686672407e6eaf8c874d4a6bf315da798f281045
-- 
2.41.0.185.g7c58973941-goog