KVM: x86: hyper-v: Use guard() instead of mutex_lock() to simplify code

[PATCH] KVM: x86: hyper-v: Use guard() instead of mutex_lock() to simplify code

Posted by Liao Yuanhong 3 months, 1 week ago

Using guard(mutex) instead of mutex_lock/mutex_unlock pair. Simplifies the
error handling to just return in case of error. No need for the
'out_unlock' label anymore so remove it.

Signed-off-by: Liao Yuanhong <liaoyuanhong@vivo.com>
---
 arch/x86/kvm/hyperv.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 72b19a88a776..a471900c7325 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1168,15 +1168,15 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
 	BUILD_BUG_ON(sizeof(tsc_seq) != sizeof(hv->tsc_ref.tsc_sequence));
 	BUILD_BUG_ON(offsetof(struct ms_hyperv_tsc_page, tsc_sequence) != 0);
 
-	mutex_lock(&hv->hv_lock);
+	guard(mutex)(&hv->hv_lock);
 
 	if (hv->hv_tsc_page_status == HV_TSC_PAGE_BROKEN ||
 	    hv->hv_tsc_page_status == HV_TSC_PAGE_SET ||
 	    hv->hv_tsc_page_status == HV_TSC_PAGE_UNSET)
-		goto out_unlock;
+		return;
 
 	if (!(hv->hv_tsc_page & HV_X64_MSR_TSC_REFERENCE_ENABLE))
-		goto out_unlock;
+		return;
 
 	gfn = hv->hv_tsc_page >> HV_X64_MSR_TSC_REFERENCE_ADDRESS_SHIFT;
 	/*
@@ -1192,7 +1192,7 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
 			goto out_err;
 
 		hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
-		goto out_unlock;
+		return;
 	}
 
 	/*
@@ -1228,12 +1228,10 @@ void kvm_hv_setup_tsc_page(struct kvm *kvm,
 		goto out_err;
 
 	hv->hv_tsc_page_status = HV_TSC_PAGE_SET;
-	goto out_unlock;
+	return;
 
 out_err:
 	hv->hv_tsc_page_status = HV_TSC_PAGE_BROKEN;
-out_unlock:
-	mutex_unlock(&hv->hv_lock);
 }
 
 void kvm_hv_request_tsc_page_update(struct kvm *kvm)
-- 
2.34.1

Re: [PATCH] KVM: x86: hyper-v: Use guard() instead of mutex_lock() to simplify code

Posted by Sean Christopherson 2 months, 4 weeks ago

On Mon, 01 Sep 2025 21:16:04 +0800, Liao Yuanhong wrote:
> Using guard(mutex) instead of mutex_lock/mutex_unlock pair. Simplifies the
> error handling to just return in case of error. No need for the
> 'out_unlock' label anymore so remove it.

Applied to kvm-x86 misc, thanks!

[1/1] KVM: x86: hyper-v: Use guard() instead of mutex_lock() to simplify code
      https://github.com/kvm-x86/linux/commit/864384e97981

--
https://github.com/kvm-x86/linux/tree/next

Re: [PATCH] KVM: x86: hyper-v: Use guard() instead of mutex_lock() to simplify code

Posted by Sean Christopherson 2 months, 4 weeks ago

On Mon, Sep 15, 2025, Sean Christopherson wrote:
> On Mon, 01 Sep 2025 21:16:04 +0800, Liao Yuanhong wrote:
> > Using guard(mutex) instead of mutex_lock/mutex_unlock pair. Simplifies the
> > error handling to just return in case of error. No need for the
> > 'out_unlock' label anymore so remove it.
> 
> Applied to kvm-x86 misc, thanks!
> 
> [1/1] KVM: x86: hyper-v: Use guard() instead of mutex_lock() to simplify code
>       https://github.com/kvm-x86/linux/commit/864384e97981

This one also got affected by the force push for an unrelated commit, new hash:

      https://github.com/kvm-x86/linux/commit/cbd860293d13