From patchwork Wed Nov 12 15:04:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Gang X-Patchwork-Id: 5290491 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 21C90C11AC for ; Wed, 12 Nov 2014 15:04:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4B34D20176 for ; Wed, 12 Nov 2014 15:04:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6C7A22015D for ; Wed, 12 Nov 2014 15:04:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752970AbaKLPEh (ORCPT ); Wed, 12 Nov 2014 10:04:37 -0500 Received: from mail-pd0-f174.google.com ([209.85.192.174]:37899 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752944AbaKLPEg (ORCPT ); Wed, 12 Nov 2014 10:04:36 -0500 Received: by mail-pd0-f174.google.com with SMTP id p10so12344965pdj.19 for ; Wed, 12 Nov 2014 07:04:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :content-type:content-transfer-encoding; bh=VzrpvrLnO1TzAUuPQmdszLjhpAFn0itSMHteZWawGps=; b=u7LCpTIKYR5dKCKOvrjJvCiY9fPUOfk9zMcV34/5ydtVLCmu8jEJQI6P6NqwqCMV8E 4inwZjxZ1ZSsQ6aE2+jStr3i4IcjTCfbh6gAivrW4zrQE1Pisze5Ci+A1eqoCCQGz2yl jHxvlFD8K7CIB7V+NR2lgyPn6b2OJlR/3iBz7ag7Sd8/DiKVV7w4SSpu3rA3TenLRRyC +ZRoc2fzY2nTx7yHP2mufu05f2NeiBmVDyCEmveon1aYhkcowSLtEUhtt+IDQd/ghCqI i3HOhRvRslu2b8pzScVl9/BKSfCwwT0DPRWe36BizbT8WtewpAs15eJFmi1s9Fpr2n1e dGoA== X-Received: by 10.66.156.41 with SMTP id wb9mr48098745pab.27.1415804676081; Wed, 12 Nov 2014 07:04:36 -0800 (PST) Received: from [192.168.1.104] ([223.72.65.118]) by mx.google.com with ESMTPSA id m5sm22497178pdi.24.2014.11.12.07.04.31 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 12 Nov 2014 07:04:34 -0800 (PST) Message-ID: <546376F7.90502@gmail.com> Date: Wed, 12 Nov 2014 23:04:23 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: christoffer.dall@linaro.org, marc.zyngier@arm.com, gleb@kernel.org, Paolo Bonzini CC: "linux-arm-kernel@lists.infradead.org" , kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, "linux-kernel@vger.kernel.org" Subject: [PATCH] virt: kvm: arm: vgic: Return failure code '-EBUSY' when mutex_trylock() fails Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When mutex_trylock() fails, kvm_vgic_create() will not create 'vgic', so it need return failure code '-EBUSY' instead of '0' to let outside know about it. Also simplify the code within kvm_vgic_create(): - kvm_for_each_vcpu() scanning once is enough for current case. - Remove redundant variable 'vcpu_lock_idx'. Signed-off-by: Chen Gang --- virt/kvm/arm/vgic.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 3aaca49..5846725 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1933,7 +1933,7 @@ out: int kvm_vgic_create(struct kvm *kvm) { - int i, vcpu_lock_idx = -1, ret = 0; + int i, ret = 0; struct kvm_vcpu *vcpu; mutex_lock(&kvm->lock); @@ -1949,13 +1949,12 @@ int kvm_vgic_create(struct kvm *kvm) * that no other VCPUs are run while we create the vgic. */ kvm_for_each_vcpu(i, vcpu, kvm) { - if (!mutex_trylock(&vcpu->mutex)) + if (!mutex_trylock(&vcpu->mutex)) { + ret = -EBUSY; goto out_unlock; - vcpu_lock_idx = i; - } - - kvm_for_each_vcpu(i, vcpu, kvm) { + } if (vcpu->arch.has_run_once) { + mutex_unlock(&vcpu->mutex); ret = -EBUSY; goto out_unlock; } @@ -1968,8 +1967,8 @@ int kvm_vgic_create(struct kvm *kvm) kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF; out_unlock: - for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) { - vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx); + while (i-- > 0) { + vcpu = kvm_get_vcpu(kvm, i); mutex_unlock(&vcpu->mutex); }