No new VCPUs can be created because we are holding the kvm->lock. This means that if we successfuly lock all VCPUs, we'll be unlocking the same set and there is no need to do extra bookkeeping.
Signed-off-by: Radim Krčmář <[email protected]> --- virt/kvm/arm/vgic/vgic-init.c | 24 +++++++++--------------- virt/kvm/arm/vgic/vgic-kvm-device.c | 6 +++++- 2 files changed, 14 insertions(+), 16 deletions(-) diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c index 5801261f3add..feb766f74c34 100644 --- a/virt/kvm/arm/vgic/vgic-init.c +++ b/virt/kvm/arm/vgic/vgic-init.c @@ -119,7 +119,7 @@ void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu) */ int kvm_vgic_create(struct kvm *kvm, u32 type) { - int i, vcpu_lock_idx = -1, ret; + int i, ret; struct kvm_vcpu *vcpu; if (irqchip_in_kernel(kvm)) @@ -140,18 +140,14 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) * vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure * that no other VCPUs are run while we create the vgic. */ - ret = -EBUSY; - kvm_for_each_vcpu(i, vcpu, kvm) { - if (!mutex_trylock(&vcpu->mutex)) - goto out_unlock; - vcpu_lock_idx = i; - } + if (!lock_all_vcpus(kvm)) + return -EBUSY; - kvm_for_each_vcpu(i, vcpu, kvm) { - if (vcpu->arch.has_run_once) + kvm_for_each_vcpu(i, vcpu, kvm) + if (vcpu->arch.has_run_once) { + ret = -EBUSY; goto out_unlock; - } - ret = 0; + } if (type == KVM_DEV_TYPE_ARM_VGIC_V2) kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS; @@ -176,11 +172,9 @@ int kvm_vgic_create(struct kvm *kvm, u32 type) kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF; kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF; + ret = 0; out_unlock: - for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { - vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx); - mutex_unlock(&vcpu->mutex); - } + unlock_all_vcpus(kvm); return ret; } diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c index 10ae6f394b71..c5124737c7fc 100644 --- a/virt/kvm/arm/vgic/vgic-kvm-device.c +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c @@ -270,7 +270,11 @@ static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx) void unlock_all_vcpus(struct kvm *kvm) { - unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1); + int i; + struct kvm_vcpu *tmp_vcpu; + + kvm_for_each_vcpu(i, tmp_vcpu, kvm) + mutex_unlock(&tmp_vcpu->mutex); } /* Returns true if all vcpus were locked, false otherwise */ -- 2.13.3
