[PATCH 6/6] KVM: SVM: Return the local "r" variable from svm_set_msr()

Sean Christopherson
2023-03-22T01:16:32Z

Rename "r" to "ret" and actually return it from svm_set_msr() to reduce
the probability of repeating the mistake of commit 723d5fb0ffe4 ("kvm:
svm: Add IA32_FLUSH_CMD guest support"), which set "r" thinking that it
would be propagated to the caller.

Alternatively, the declaration of "r" could be moved into the handling of
MSR_TSC_AUX, but that risks variable shadowing in the future. A wrapper
for kvm_set_user_return_msr() would allow eliding a local variable, but
that feels like delaying the inevitable.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kvm/svm/svm.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b32edaf5a74b..57f241c5a371 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2873,7 +2873,7 @@ static int svm_set_vm_cr(struct kvm_vcpu *vcpu, u64 data)
static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
{
struct vcpu_svm *svm = to_svm(vcpu);
- int r;
+ int ret = 0;

u32 ecx = msr->index;
u64 data = msr->data;
@@ -2995,10 +2995,10 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
* guest via direct_access_msrs, and switch it via user return.
*/
preempt_disable();
- r = kvm_set_user_return_msr(tsc_aux_uret_slot, data, -1ull);
+ ret = kvm_set_user_return_msr(tsc_aux_uret_slot, data, -1ull);
preempt_enable();
- if (r)
- return 1;
+ if (ret)
+ break;

svm->tsc_aux = data;
break;
@@ -3056,7 +3056,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
default:
return kvm_set_msr_common(vcpu, msr);
}
- return 0;
+ return ret;
}

static int msr_interception(struct kvm_vcpu *vcpu)
--
2.40.0.rc2.332.ga46443480c-goog