From patchwork Tue Sep 15 10:49:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Kardashevskiy X-Patchwork-Id: 517822 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D4C491401DE for ; Tue, 15 Sep 2015 20:51:27 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752335AbbIOKvG (ORCPT ); Tue, 15 Sep 2015 06:51:06 -0400 Received: from e23smtp03.au.ibm.com ([202.81.31.145]:43832 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752340AbbIOKvD (ORCPT ); Tue, 15 Sep 2015 06:51:03 -0400 Received: from /spool/local by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 15 Sep 2015 20:50:59 +1000 X-Helo: d23dlp02.au.ibm.com X-MailFrom: aik@ozlabs.ru X-RcptTo: kvm@vger.kernel.org Received: from d23relay07.au.ibm.com (d23relay07.au.ibm.com [9.190.26.37]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 6BC652BB0055; Tue, 15 Sep 2015 20:50:59 +1000 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay07.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t8FAoq6T54526110; Tue, 15 Sep 2015 20:51:00 +1000 Received: from d23av03.au.ibm.com (localhost [127.0.0.1]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t8FAoQoK028826; Tue, 15 Sep 2015 20:50:27 +1000 Received: from ozlabs.au.ibm.com (ozlabs.au.ibm.com [9.192.253.14]) by d23av03.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id t8FAoQ2n028429; Tue, 15 Sep 2015 20:50:26 +1000 Received: from bran.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) by ozlabs.au.ibm.com (Postfix) with ESMTP id 1993CA03DD; Tue, 15 Sep 2015 20:49:42 +1000 (AEST) Received: from ka1.ozlabs.ibm.com (ka1.ozlabs.ibm.com [10.61.145.11]) by bran.ozlabs.ibm.com (Postfix) with ESMTP id 11FD8E450B; Tue, 15 Sep 2015 20:49:42 +1000 (AEST) From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Paul Mackerras , Alexander Graf , David Gibson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH kernel 4/9] KVM: PPC: Use RCU for arch.spapr_tce_tables Date: Tue, 15 Sep 2015 20:49:34 +1000 Message-Id: <1442314179-9706-5-git-send-email-aik@ozlabs.ru> X-Mailer: git-send-email 2.4.0.rc3.8.gfb3e7d5 In-Reply-To: <1442314179-9706-1-git-send-email-aik@ozlabs.ru> References: <1442314179-9706-1-git-send-email-aik@ozlabs.ru> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15091510-0009-0000-0000-0000020F65F1 Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org At the moment spapr_tce_tables is not protected against races. This makes use of RCU-variants of list helpers. As some bits are executed in real mode, this makes use of just introduced list_for_each_entry_rcu_notrace(). This converts release_spapr_tce_table() to a RCU scheduled handler. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson --- arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kvm/book3s.c | 2 +- arch/powerpc/kvm/book3s_64_vio.c | 20 +++++++++++--------- 3 files changed, 13 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 98eebbf6..e19d412 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -178,6 +178,7 @@ struct kvmppc_spapr_tce_table { struct kvm *kvm; u64 liobn; u32 window_size; + struct rcu_head rcu; struct page *pages[0]; }; diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 53285d5..3418f7c 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -806,7 +806,7 @@ int kvmppc_core_init_vm(struct kvm *kvm) { #ifdef CONFIG_PPC64 - INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables); + INIT_LIST_HEAD_RCU(&kvm->arch.spapr_tce_tables); INIT_LIST_HEAD(&kvm->arch.rtas_tokens); #endif diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index 54cf9bc..9526c34 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -45,19 +45,16 @@ static long kvmppc_stt_npages(unsigned long window_size) * sizeof(u64), PAGE_SIZE) / PAGE_SIZE; } -static void release_spapr_tce_table(struct kvmppc_spapr_tce_table *stt) +static void release_spapr_tce_table(struct rcu_head *head) { - struct kvm *kvm = stt->kvm; + struct kvmppc_spapr_tce_table *stt = container_of(head, + struct kvmppc_spapr_tce_table, rcu); int i; - mutex_lock(&kvm->lock); - list_del(&stt->list); for (i = 0; i < kvmppc_stt_npages(stt->window_size); i++) __free_page(stt->pages[i]); + kfree(stt); - mutex_unlock(&kvm->lock); - - kvm_put_kvm(kvm); } static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf) @@ -88,7 +85,12 @@ static int kvm_spapr_tce_release(struct inode *inode, struct file *filp) { struct kvmppc_spapr_tce_table *stt = filp->private_data; - release_spapr_tce_table(stt); + list_del_rcu(&stt->list); + + kvm_put_kvm(stt->kvm); + + call_rcu(&stt->rcu, release_spapr_tce_table); + return 0; } @@ -131,7 +133,7 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, kvm_get_kvm(kvm); mutex_lock(&kvm->lock); - list_add(&stt->list, &kvm->arch.spapr_tce_tables); + list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables); mutex_unlock(&kvm->lock);