kvm: use the correct RCU API

Message ID	4BCC2543.7050104@cn.fujitsu.com (mailing list archive)
State	New, archived
Headers	show Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o3J9gNKr018557 for <patchwork-kvm@patchwork.kernel.org>; Mon, 19 Apr 2010 09:42:45 GMT Message-ID: <4BCC2543.7050104@cn.fujitsu.com> Date: Mon, 19 Apr 2010 17:41:23 +0800 From: Lai Jiangshan <laijs@cn.fujitsu.com> User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>, Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>, kvm@vger.kernel.org Subject: [PATCH] kvm: use the correct RCU API Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: kvm-owner@vger.kernel.org Precedence: bulk

=================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/8550: #0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm] stack backtrace: Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27 Call Trace: [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm] [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm] [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [<ffffffff810a8692>] ? unlock_page+0x27/0x2c [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm] [<ffffffff81060cfa>] ? up_read+0x23/0x3d [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a [<ffffffff810021db>] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 73c5c2b..52b8ece 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1379,7 +1379,7 @@ static void kvm_release_vm_pages(struct kvm *kvm) int i, j; unsigned long base_gfn; - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; i++) { memslot = &slots->memslots[i]; base_gfn = memslot->base_gfn; diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index 60f09ab..cfa9d17 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -72,7 +72,7 @@ static inline void kvm_s390_vcpu_set_mem(struct kvm_vcpu *vcpu) struct kvm_memslots *memslots; idx = srcu_read_lock(&vcpu->kvm->srcu); - memslots = rcu_dereference(vcpu->kvm->memslots); + memslots = kvm_memslots(vcpu->kvm); mem = &memslots->memslots[0]; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 71faa04..bb61881 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -792,7 +792,7 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, int retval = 0; struct kvm_memslots *slots; - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; i++) { struct kvm_memory_slot *memslot = &slots->memslots[i]; @@ -3017,7 +3017,8 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm) unsigned int nr_pages = 0; struct kvm_memslots *slots; - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); + for (i = 0; i < slots->nmemslots; i++) nr_pages += slots->memslots[i].npages; @@ -3292,7 +3293,7 @@ static int count_rmaps(struct kvm_vcpu *vcpu) int i, j, k, idx; idx = srcu_read_lock(&kvm->srcu); - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { struct kvm_memory_slot *m = &slots->memslots[i]; struct kvm_rmap_desc *d; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 077cac5..725e7b6 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1514,7 +1514,7 @@ static gva_t rmode_tss_base(struct kvm *kvm) struct kvm_memslots *slots; gfn_t base_gfn; - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); base_gfn = kvm->memslots->memslots[0].base_gfn + kvm->memslots->memslots[0].npages - 3; return base_gfn << PAGE_SHIFT; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6120e33..4dcd62c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2408,7 +2408,7 @@ gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn) struct kvm_mem_alias *alias; struct kvm_mem_aliases *aliases; - aliases = rcu_dereference(kvm->arch.aliases); + aliases = kvm_aliases(kvm); for (i = 0; i < aliases->naliases; ++i) { alias = &aliases->aliases[i]; @@ -2427,7 +2427,7 @@ gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) struct kvm_mem_alias *alias; struct kvm_mem_aliases *aliases; - aliases = rcu_dereference(kvm->arch.aliases); + aliases = kvm_aliases(kvm); for (i = 0; i < aliases->naliases; ++i) { alias = &aliases->aliases[i]; diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index 2d10163..e218fed 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -65,4 +65,11 @@ static inline int is_paging(struct kvm_vcpu *vcpu) return kvm_read_cr0_bits(vcpu, X86_CR0_PG); } +static inline struct kvm_mem_aliases *kvm_aliases(struct kvm *kvm) +{ + return rcu_dereference_check(kvm->arch.aliases, + srcu_read_lock_held(&kvm->srcu) + || lockdep_is_held(&kvm->slots_lock)); +} + #endif diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index a3fd0f9..f735752 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -239,6 +239,13 @@ void kvm_exit(void); void kvm_get_kvm(struct kvm *kvm); void kvm_put_kvm(struct kvm *kvm); +static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm) +{ + return rcu_dereference_check(kvm->memslots, + srcu_read_lock_held(&kvm->srcu) + || lockdep_is_held(&kvm->slots_lock)); +} + #define HPA_MSB ((sizeof(hpa_t) * 8) - 1) #define HPA_ERR_MASK ((hpa_t)1 << HPA_MSB) static inline int is_error_hpa(hpa_t hpa) { return hpa >> HPA_MSB; } diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index 80fd3ad..37ca71e 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -78,7 +78,7 @@ static int kvm_iommu_map_memslots(struct kvm *kvm) int i, r = 0; struct kvm_memslots *slots; - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; i++) { r = kvm_iommu_map_pages(kvm, &slots->memslots[i]); @@ -217,7 +217,7 @@ static int kvm_iommu_unmap_memslots(struct kvm *kvm) int i; struct kvm_memslots *slots; - slots = rcu_dereference(kvm->memslots); + slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; i++) { kvm_iommu_put_pages(kvm, slots->memslots[i].base_gfn, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index b03f863..58b2147 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -829,7 +829,7 @@ EXPORT_SYMBOL_GPL(kvm_is_error_hva); struct kvm_memory_slot *gfn_to_memslot_unaliased(struct kvm *kvm, gfn_t gfn) { int i; - struct kvm_memslots *slots = rcu_dereference(kvm->memslots); + struct kvm_memslots *slots = kvm_memslots(kvm); for (i = 0; i < slots->nmemslots; ++i) { struct kvm_memory_slot *memslot = &slots->memslots[i]; @@ -851,7 +851,7 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { int i; - struct kvm_memslots *slots = rcu_dereference(kvm->memslots); + struct kvm_memslots *slots = kvm_memslots(kvm); gfn = unalias_gfn_instantiation(kvm, gfn); for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { @@ -895,7 +895,7 @@ out: int memslot_id(struct kvm *kvm, gfn_t gfn) { int i; - struct kvm_memslots *slots = rcu_dereference(kvm->memslots); + struct kvm_memslots *slots = kvm_memslots(kvm); struct kvm_memory_slot *memslot = NULL; gfn = unalias_gfn(kvm, gfn); @@ -1979,7 +1979,9 @@ int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val) { int i; - struct kvm_io_bus *bus = rcu_dereference(kvm->buses[bus_idx]); + struct kvm_io_bus *bus; + + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); for (i = 0; i < bus->dev_count; i++) if (!kvm_iodevice_write(bus->devs[i], addr, len, val)) return 0; @@ -1991,8 +1993,9 @@ int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, void *val) { int i; - struct kvm_io_bus *bus = rcu_dereference(kvm->buses[bus_idx]); + struct kvm_io_bus *bus; + bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); for (i = 0; i < bus->dev_count; i++) if (!kvm_iodevice_read(bus->devs[i], addr, len, val)) return 0;

kvm: use the correct RCU API

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