From patchwork Mon May 25 15:50:35 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 25851 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n4PFp68s022434 for ; Mon, 25 May 2009 15:51:06 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752839AbZEYPuh (ORCPT ); Mon, 25 May 2009 11:50:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752803AbZEYPug (ORCPT ); Mon, 25 May 2009 11:50:36 -0400 Received: from mx2.redhat.com ([66.187.237.31]:57852 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbZEYPug (ORCPT ); Mon, 25 May 2009 11:50:36 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n4PFocFl017672 for ; Mon, 25 May 2009 11:50:38 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n4PFobTr004496 for ; Mon, 25 May 2009 11:50:37 -0400 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n4PFoaE9032479 for ; Mon, 25 May 2009 11:50:36 -0400 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 13519) id 2F1BC18D465; Mon, 25 May 2009 18:50:36 +0300 (IDT) From: Gleb Natapov To: kvm@vger.kernel.org Subject: [PATCH RFC v2 3/4] Break dependency between vcpu index in vcpus array and vcpu_id. Date: Mon, 25 May 2009 18:50:35 +0300 Message-Id: <1243266636-16914-4-git-send-email-gleb@redhat.com> In-Reply-To: <1243266636-16914-1-git-send-email-gleb@redhat.com> References: <1243266636-16914-1-git-send-email-gleb@redhat.com> X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Archs are free to use vcpu_id as they see fit. For x86 it is used as vcpu's apic id. Signed-off-by: Gleb Natapov --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 45 ++++++++++++++++++++++++--------------------- 2 files changed, 25 insertions(+), 21 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index e9e0cd8..0934df3 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -132,6 +132,7 @@ struct kvm { KVM_PRIVATE_MEM_SLOTS]; struct kvm_vcpu *bsp_vcpu; struct kvm_vcpu *vcpus[KVM_MAX_VCPUS]; + atomic_t online_vcpus; struct list_head vm_list; struct kvm_io_bus mmio_bus; struct kvm_io_bus pio_bus; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5a55fe0..8f3fff8 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -693,11 +693,6 @@ out: } #endif -static inline int valid_vcpu(int n) -{ - return likely(n >= 0 && n < KVM_MAX_VCPUS); -} - inline int kvm_is_mmio_pfn(pfn_t pfn) { if (pfn_valid(pfn)) { @@ -1713,15 +1708,12 @@ static int create_vcpu_fd(struct kvm_vcpu *vcpu) /* * Creates some virtual cpus. Good luck creating more than one. */ -static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n) +static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) { int r; struct kvm_vcpu *vcpu; - if (!valid_vcpu(n)) - return -EINVAL; - - vcpu = kvm_arch_vcpu_create(kvm, n); + vcpu = kvm_arch_vcpu_create(kvm, id); if (IS_ERR(vcpu)) return PTR_ERR(vcpu); @@ -1732,25 +1724,36 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n) return r; mutex_lock(&kvm->lock); - if (kvm->vcpus[n]) { - r = -EEXIST; + if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) { + r = -EINVAL; goto vcpu_destroy; } - kvm->vcpus[n] = vcpu; - if (n == 0) - kvm->bsp_vcpu = vcpu; - mutex_unlock(&kvm->lock); + + for (r = 0; r < atomic_read(&kvm->online_vcpus); r++) + if (kvm->vcpus[r]->vcpu_id == id) { + r = -EEXIST; + goto vcpu_destroy; + } + + BUG_ON(kvm->vcpus[atomic_read(&kvm->online_vcpus)]); /* Now it's all set up, let userspace reach it */ kvm_get_kvm(kvm); r = create_vcpu_fd(vcpu); - if (r < 0) - goto unlink; + if (r < 0) { + kvm_put_kvm(kvm); + goto vcpu_destroy; + } + + kvm->vcpus[atomic_read(&kvm->online_vcpus)] = vcpu; + smp_wmb(); + atomic_inc(&kvm->online_vcpus); + + if (id == 0) + kvm->bsp_vcpu = vcpu; + mutex_unlock(&kvm->lock); return r; -unlink: - mutex_lock(&kvm->lock); - kvm->vcpus[n] = NULL; vcpu_destroy: mutex_unlock(&kvm->lock); kvm_arch_vcpu_destroy(vcpu);