Re: [PATCH] kvm: x86: hyperv: delete dead code in kvm_hv_hypercall()

Paolo Bonzini
2018-03-23T19:12:17Z

On 17/03/2018 12:48, Dan Carpenter wrote:
> "rep_done" is always zero so the "(((u64)rep_done & 0xfff) << 32)"
> expression is just zero. We can remove the "res" temporary variable as
> well and just use "ret" directly.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> index 53bd1913b6fd..80c34c83f882 100644
> --- a/arch/x86/kvm/hyperv.c
> +++ b/arch/x86/kvm/hyperv.c
> @@ -1266,8 +1266,8 @@ static u16 kvm_hvcall_signal_event(struct kvm_vcpu *vcpu, bool fast, u64 param)
>
> int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
> {
> - u64 param, ingpa, outgpa, ret;
> - uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS, rep_done = 0;
> + u64 param, ingpa, outgpa, ret = HV_STATUS_SUCCESS;
> + uint16_t code, rep_idx, rep_cnt;
> bool fast, longmode;
>
> /*
> @@ -1306,7 +1306,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>
> /* Hypercall continuation is not supported yet */
> if (rep_cnt || rep_idx) {
> - res = HV_STATUS_INVALID_HYPERCALL_CODE;
> + ret = HV_STATUS_INVALID_HYPERCALL_CODE;
> goto set_result;
> }
>
> @@ -1315,14 +1315,14 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
> kvm_vcpu_on_spin(vcpu, true);
> break;
> case HVCALL_SIGNAL_EVENT:
> - res = kvm_hvcall_signal_event(vcpu, fast, ingpa);
> - if (res != HV_STATUS_INVALID_PORT_ID)
> + ret = kvm_hvcall_signal_event(vcpu, fast, ingpa);
> + if (ret != HV_STATUS_INVALID_PORT_ID)
> break;
> /* maybe userspace knows this conn_id: fall through */
> case HVCALL_POST_MESSAGE:
> /* don't bother userspace if it has no way to handle it */
> if (!vcpu_to_synic(vcpu)->active) {
> - res = HV_STATUS_INVALID_HYPERCALL_CODE;
> + ret = HV_STATUS_INVALID_HYPERCALL_CODE;
> break;
> }
> vcpu->run->exit_reason = KVM_EXIT_HYPERV;
> @@ -1334,12 +1334,11 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
> kvm_hv_hypercall_complete_userspace;
> return 0;
> default:
> - res = HV_STATUS_INVALID_HYPERCALL_CODE;
> + ret = HV_STATUS_INVALID_HYPERCALL_CODE;
> break;
> }
>
> set_result:
> - ret = res | (((u64)rep_done & 0xfff) << 32);
> kvm_hv_hypercall_set_result(vcpu, ret);
> return 1;
> }
>

Queued, thanks.

Paolo