From 90d83dc3d49f5101addae962ccc1b4aff66b68d8 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Mon, 19 Apr 2010 17:41:23 +0800 Subject: KVM: use the correct RCU API for PROVE_RCU=y The RCU/SRCU API have already changed for proving RCU usage. I got the following dmesg when PROVE_RCU=y because we used incorrect API. This patch coverts rcu_deference() to srcu_dereference() or family API. =================================================== [ 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: [] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [] 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: [] lockdep_rcu_dereference+0xaa/0xb3 [] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [] __kvm_set_memory_region+0x636/0x6e2 [kvm] [] kvm_set_memory_region+0x37/0x50 [kvm] [] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [] ? unlock_page+0x27/0x2c [] ? __do_fault+0x3a9/0x3e1 [] kvm_vm_ioctl+0x364/0x38d [kvm] [] ? up_read+0x23/0x3d [] vfs_ioctl+0x32/0xa6 [] do_vfs_ioctl+0x495/0x4db [] ? fget_light+0xc2/0x241 [] ? do_sys_open+0x104/0x116 [] ? retint_swapgs+0xe/0x13 [] sys_ioctl+0x47/0x6a [] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan Signed-off-by: Avi Kivity --- arch/ia64/kvm/kvm-ia64.c | 2 +- arch/s390/kvm/kvm-s390.h | 2 +- arch/x86/kvm/mmu.c | 7 ++++--- arch/x86/kvm/vmx.c | 2 +- arch/x86/kvm/x86.c | 4 ++-- arch/x86/kvm/x86.h | 7 +++++++ 6 files changed, 16 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index d7bac1f75af..d5f4e916120 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -1381,7 +1381,7 @@ 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 60f09ab3672..cfa9d177745 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 7a17db1cdcd..0682a393ad9 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -787,7 +787,7 @@ 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]; @@ -3016,7 +3016,8 @@ 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 0b896ac7e4b..d0a10b5612e 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1558,7 +1558,7 @@ 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 58a96e6a234..638248c9699 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2497,7 +2497,7 @@ 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]; @@ -2516,7 +2516,7 @@ 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 b7a404722d2..f4b54458285 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -65,6 +65,13 @@ 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)); +} + void kvm_before_handle_nmi(struct kvm_vcpu *vcpu); void kvm_after_handle_nmi(struct kvm_vcpu *vcpu); -- cgit v1.2.3