From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Kardashevskiy 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> References: <1442314179-9706-1-git-send-email-aik@ozlabs.ru> Cc: Alexey Kardashevskiy , Paul Mackerras , Alexander Graf , David Gibson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org To: linuxppc-dev@lists.ozlabs.org Return-path: Received: from e23smtp03.au.ibm.com ([202.81.31.145]:43831 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752339AbbIOKvD (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! Violators will be prosecuted for from ; Tue, 15 Sep 2015 20:51:01 +1000 In-Reply-To: <1442314179-9706-1-git-send-email-aik@ozlabs.ru> Sender: kvm-owner@vger.kernel.org List-ID: 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 --- 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); -- 2.4.0.rc3.8.gfb3e7d5 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexey Kardashevskiy Date: Tue, 15 Sep 2015 10:49:34 +0000 Subject: [PATCH kernel 4/9] KVM: PPC: Use RCU for arch.spapr_tce_tables Message-Id: <1442314179-9706-5-git-send-email-aik@ozlabs.ru> List-Id: References: <1442314179-9706-1-git-send-email-aik@ozlabs.ru> In-Reply-To: <1442314179-9706-1-git-send-email-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linuxppc-dev@lists.ozlabs.org Cc: Alexey Kardashevskiy , Paul Mackerras , Alexander Graf , David Gibson , kvm-ppc@vger.kernel.org, kvm@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 --- 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); -- 2.4.0.rc3.8.gfb3e7d5