From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp01.au.ibm.com (e23smtp01.au.ibm.com [202.81.31.143]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 679E11A076C for ; Thu, 21 Jan 2016 18:40:42 +1100 (AEDT) Received: from localhost by e23smtp01.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 21 Jan 2016 17:40:42 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp01.au.ibm.com (Postfix) with ESMTP id 37F062CE802D for ; Thu, 21 Jan 2016 18:40:39 +1100 (EST) Received: from d23av03.au.ibm.com (d23av03.au.ibm.com [9.190.234.97]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u0L7eRXj50462840 for ; Thu, 21 Jan 2016 18:40:39 +1100 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 u0L7e3hq012514 for ; Thu, 21 Jan 2016 18:40:03 +1100 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Paul Mackerras , David Gibson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Subject: [PATCH kernel v2 2/6] KVM: PPC: Use RCU for arch.spapr_tce_tables Date: Thu, 21 Jan 2016 18:39:33 +1100 Message-Id: <1453361977-19589-3-git-send-email-aik@ozlabs.ru> In-Reply-To: <1453361977-19589-1-git-send-email-aik@ozlabs.ru> References: <1453361977-19589-1-git-send-email-aik@ozlabs.ru> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 271fefb..c7ee696 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -184,6 +184,7 @@ 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 638c6d9..b34220d 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -807,7 +807,7 @@ 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); -- 2.5.0.rc3