Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754388AbdHUUiY (ORCPT ); Mon, 21 Aug 2017 16:38:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56132 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754340AbdHUUiU (ORCPT ); Mon, 21 Aug 2017 16:38:20 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7858781E0C Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=rkrcmar@redhat.com From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mips@linux-mips.org, kvm-ppc@vger.kernel.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Paolo Bonzini , David Hildenbrand , Christoffer Dall , Marc Zyngier , Christian Borntraeger , Cornelia Huck , James Hogan , Paul Mackerras , Alexander Graf Subject: [PATCH RFC v3 4/9] KVM: arm/arm64: use locking helpers in kvm_vgic_create() Date: Mon, 21 Aug 2017 22:35:25 +0200 Message-Id: <20170821203530.9266-5-rkrcmar@redhat.com> In-Reply-To: <20170821203530.9266-1-rkrcmar@redhat.com> References: <20170821203530.9266-1-rkrcmar@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Mon, 21 Aug 2017 20:38:20 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2464 Lines: 81 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 --- 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