[PATCH 07/10] KVM: arm64: Use scoped resource management in arm.c
From: Fuad Tabba <tabba@google.com>
Date: 2026-03-16 17:35:39
Also in:
kvmarm, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
Migrate manual spin_lock() calls managing mp_state_lock and manual mutex_lock() calls managing kvm->arch.config_lock to use the guard(spinlock) and guard(mutex) macros. This eliminates manual unlock calls on early return paths and simplifies the vCPU suspend/resume control flow. Change-Id: Ifcd8455d08afa5d00fc200daaa3fb13f6736e6ed Signed-off-by: Fuad Tabba <tabba@google.com> --- arch/arm64/kvm/arm.c | 53 ++++++++++++++++++++-------------------------------- 1 file changed, 20 insertions(+), 33 deletions(-)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 410ffd41fd73..017f5bfabe19 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c@@ -274,17 +274,15 @@ static void kvm_destroy_mpidr_data(struct kvm *kvm) { struct kvm_mpidr_data *data; - mutex_lock(&kvm->arch.config_lock); - - data = rcu_dereference_protected(kvm->arch.mpidr_data, - lockdep_is_held(&kvm->arch.config_lock)); - if (data) { - rcu_assign_pointer(kvm->arch.mpidr_data, NULL); - synchronize_rcu(); - kfree(data); + scoped_guard(mutex, &kvm->arch.config_lock) { + data = rcu_dereference_protected(kvm->arch.mpidr_data, + lockdep_is_held(&kvm->arch.config_lock)); + if (data) { + rcu_assign_pointer(kvm->arch.mpidr_data, NULL); + synchronize_rcu(); + kfree(data); + } } - - mutex_unlock(&kvm->arch.config_lock); } /**
@@ -738,9 +736,8 @@ static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu) { - spin_lock(&vcpu->arch.mp_state_lock); + guard(spinlock)(&vcpu->arch.mp_state_lock); __kvm_arm_vcpu_power_off(vcpu); - spin_unlock(&vcpu->arch.mp_state_lock); } bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu)
@@ -773,7 +770,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, { int ret = 0; - spin_lock(&vcpu->arch.mp_state_lock); + guard(spinlock)(&vcpu->arch.mp_state_lock); switch (mp_state->mp_state) { case KVM_MP_STATE_RUNNABLE:
@@ -789,8 +786,6 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, ret = -EINVAL; } - spin_unlock(&vcpu->arch.mp_state_lock); - return ret; }
@@ -828,11 +823,11 @@ static void kvm_init_mpidr_data(struct kvm *kvm) u64 aff_set = 0, aff_clr = ~0UL; struct kvm_vcpu *vcpu; - mutex_lock(&kvm->arch.config_lock); + guard(mutex)(&kvm->arch.config_lock); if (rcu_access_pointer(kvm->arch.mpidr_data) || atomic_read(&kvm->online_vcpus) == 1) - goto out; + return; kvm_for_each_vcpu(c, vcpu, kvm) { u64 aff = kvm_vcpu_get_mpidr_aff(vcpu);
@@ -857,7 +852,7 @@ static void kvm_init_mpidr_data(struct kvm *kvm) GFP_KERNEL_ACCOUNT); if (!data) - goto out; + return; data->mpidr_mask = mask;
@@ -869,8 +864,6 @@ static void kvm_init_mpidr_data(struct kvm *kvm) } rcu_assign_pointer(kvm->arch.mpidr_data, data); -out: - mutex_unlock(&kvm->arch.config_lock); } /*
@@ -944,9 +937,8 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) return ret; } - mutex_lock(&kvm->arch.config_lock); + guard(mutex)(&kvm->arch.config_lock); set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags); - mutex_unlock(&kvm->arch.config_lock); return ret; }
@@ -1585,29 +1577,26 @@ static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu, { unsigned long features = init->features[0]; struct kvm *kvm = vcpu->kvm; - int ret = -EINVAL; + int ret; - mutex_lock(&kvm->arch.config_lock); + guard(mutex)(&kvm->arch.config_lock); if (test_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags) && kvm_vcpu_init_changed(vcpu, init)) - goto out_unlock; + return -EINVAL; bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES); ret = kvm_setup_vcpu(vcpu); if (ret) - goto out_unlock; + return ret; /* Now we know what it is, we can reset it. */ kvm_reset_vcpu(vcpu); set_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags); vcpu_set_flag(vcpu, VCPU_INITIALIZED); - ret = 0; -out_unlock: - mutex_unlock(&kvm->arch.config_lock); - return ret; + return 0; } static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
@@ -1674,15 +1663,13 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, /* * Handle the "start in power-off" case. */ - spin_lock(&vcpu->arch.mp_state_lock); + guard(spinlock)(&vcpu->arch.mp_state_lock); if (power_off) __kvm_arm_vcpu_power_off(vcpu); else WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE); - spin_unlock(&vcpu->arch.mp_state_lock); - return 0; }
--
2.53.0.851.ga537e3e6e9-goog