linux-kernel - [PATCH v4 24/28] KVM: TDX: Use guard() to acquire kvm->lock in tdx_vm

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Message-ID: <20251030200951.3402865-25-seanjc@google.com>
Date: Thu, 30 Oct 2025 13:09:47 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Tianrui Zhao <zhaotianrui@...ngson.cn>, Bibo Mao <maobibo@...ngson.cn>, 
	Huacai Chen <chenhuacai@...nel.org>, Madhavan Srinivasan <maddy@...ux.ibm.com>, 
	Anup Patel <anup@...infault.org>, Paul Walmsley <pjw@...nel.org>, 
	Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>, 
	Christian Borntraeger <borntraeger@...ux.ibm.com>, Janosch Frank <frankja@...ux.ibm.com>, 
	Claudio Imbrenda <imbrenda@...ux.ibm.com>, Sean Christopherson <seanjc@...gle.com>, 
	Paolo Bonzini <pbonzini@...hat.com>, "Kirill A. Shutemov" <kas@...nel.org>
Cc: linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	kvm@...r.kernel.org, loongarch@...ts.linux.dev, linux-mips@...r.kernel.org, 
	linuxppc-dev@...ts.ozlabs.org, kvm-riscv@...ts.infradead.org, 
	linux-riscv@...ts.infradead.org, x86@...nel.org, linux-coco@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, Ira Weiny <ira.weiny@...el.com>, 
	Kai Huang <kai.huang@...el.com>, Binbin Wu <binbin.wu@...ux.intel.com>, 
	Michael Roth <michael.roth@....com>, Yan Zhao <yan.y.zhao@...el.com>, 
	Vishal Annapurve <vannapurve@...gle.com>, Rick Edgecombe <rick.p.edgecombe@...el.com>, 
	Ackerley Tng <ackerleytng@...gle.com>
Subject: [PATCH v4 24/28] KVM: TDX: Use guard() to acquire kvm->lock in tdx_vm_ioctl()

Use guard() in tdx_vm_ioctl() to tidy up the code a small amount, but more
importantly to minimize the diff of a future change, which will use
guard-like semantics to acquire and release multiple locks.

No functional change intended.

Reviewed-by: Rick Edgecombe <rick.p.edgecombe@...el.com>
Reviewed-by: Kai Huang <kai.huang@...el.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/vmx/tdx.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index d6f40a481487..037429964fd7 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -2806,7 +2806,7 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 	if (r)
 		return r;
 
-	mutex_lock(&kvm->lock);
+	guard(mutex)(&kvm->lock);
 
 	switch (tdx_cmd.id) {
 	case KVM_TDX_CAPABILITIES:
@@ -2819,15 +2819,12 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 		r = tdx_td_finalize(kvm, &tdx_cmd);
 		break;
 	default:
-		r = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 
 	if (copy_to_user(argp, &tdx_cmd, sizeof(struct kvm_tdx_cmd)))
-		r = -EFAULT;
+		return -EFAULT;
 
-out:
-	mutex_unlock(&kvm->lock);
 	return r;
 }
 
-- 
2.51.1.930.gacf6e81ea2-goog