From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp09.au.ibm.com (e23smtp09.au.ibm.com [202.81.31.142]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 1F47F1A01A4 for ; Wed, 30 Jul 2014 19:31:44 +1000 (EST) Received: from /spool/local by e23smtp09.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 30 Jul 2014 19:31:23 +1000 Received: from d23relay03.au.ibm.com (d23relay03.au.ibm.com [9.190.235.21]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 6B5912BB0057 for ; Wed, 30 Jul 2014 19:31:39 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s6U9VFx523134388 for ; Wed, 30 Jul 2014 19:31:15 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s6U9VcE4026586 for ; Wed, 30 Jul 2014 19:31:39 +1000 From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 02/16] KVM: PPC: Use RCU for arch.spapr_tce_tables Date: Wed, 30 Jul 2014 19:31:21 +1000 Message-Id: <1406712695-9491-3-git-send-email-aik@ozlabs.ru> In-Reply-To: <1406712695-9491-1-git-send-email-aik@ozlabs.ru> References: <1406712695-9491-1-git-send-email-aik@ozlabs.ru> Cc: Alexey Kardashevskiy , Michael Ellerman , Paul Mackerras , Gavin Shan 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 --- Changes: * total rework * kfree() for kvmppc_spapr_tce_table is moved to call_rcu_sched() callback * used new list_for_each_entry_rcu_notrace --- arch/powerpc/include/asm/kvm_host.h | 1 + arch/powerpc/kvm/book3s.c | 2 +- arch/powerpc/kvm/book3s_64_vio.c | 23 +++++++++++++---------- arch/powerpc/kvm/book3s_64_vio_hv.c | 6 ++++-- 4 files changed, 19 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index bb66d8b..cd22c31 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -180,6 +180,7 @@ 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 c254c27..9e17d19 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -886,7 +886,7 @@ 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..5958f7d 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]); + kvm_put_kvm(stt->kvm); 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) @@ -87,8 +84,13 @@ static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma) static int kvm_spapr_tce_release(struct inode *inode, struct file *filp) { struct kvmppc_spapr_tce_table *stt = filp->private_data; + struct kvm *kvm = stt->kvm; + + mutex_lock(&kvm->lock); + list_del_rcu(&stt->list); + call_rcu_sched(&stt->rcu, release_spapr_tce_table); + mutex_unlock(&kvm->lock); - release_spapr_tce_table(stt); return 0; } @@ -106,7 +108,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, int i; /* Check this LIOBN hasn't been previously allocated */ - list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) { + list_for_each_entry_rcu_notrace(stt, &kvm->arch.spapr_tce_tables, + list) { if (stt->liobn == args->liobn) return -EBUSY; } @@ -131,7 +134,7 @@ 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); diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c index 89e96b3..b1914d9 100644 --- a/arch/powerpc/kvm/book3s_64_vio_hv.c +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c @@ -50,7 +50,8 @@ long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */ /* liobn, ioba, tce); */ - list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) { + list_for_each_entry_rcu_notrace(stt, &kvm->arch.spapr_tce_tables, + list) { if (stt->liobn == liobn) { unsigned long idx = ioba >> SPAPR_TCE_SHIFT; struct page *page; @@ -82,7 +83,8 @@ long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn, struct kvm *kvm = vcpu->kvm; struct kvmppc_spapr_tce_table *stt; - list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) { + list_for_each_entry_rcu_notrace(stt, &kvm->arch.spapr_tce_tables, + list) { if (stt->liobn == liobn) { unsigned long idx = ioba >> SPAPR_TCE_SHIFT; struct page *page; -- 2.0.0