[Devel] [PATCH RHEL7 COMMIT] kvm: x86: hyperv: delete dead code in kvm_hv_hypercall()

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-693.21.1.vz7.47.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.21.1.vz7.47.2
------>
commit 293e95a3c2b67c325e2bdb030eb9973ff3c389f7
Author: Dan Carpenter <dan.carpenter at oracle.com>
Date:   Fri Apr 27 13:34:53 2018 +0300

    kvm: x86: hyperv: delete dead code in kvm_hv_hypercall()
    
    "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 at oracle.com>
    Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
    
    (cherry picked from commit d32ef547fdbbeb9c4351f9d3bc84dec998a3be8c)
    Signed-off-by: Roman Kagan <rkagan at virtuozzo.com>
---
 arch/x86/kvm/hyperv.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index c6d95a97c44c..d31d37c8765a 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1280,8 +1280,8 @@ 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;
 
 	/*
@@ -1320,7 +1320,7 @@ 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;
 	}
 
@@ -1329,14 +1329,14 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
 		kvm_vcpu_on_spin(vcpu);
 		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;
@@ -1348,12 +1348,11 @@ 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;
 }