Merge branch 'annotations' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeg...

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 0b50e7b..648b34c 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -234,7 +234,7 @@ struct kvm_vcpu {
 
        int guest_fpu_loaded, guest_xcr0_loaded;
        struct swait_queue_head wq;
-       struct pid *pid;
+       struct pid __rcu *pid;
        int sigset_active;
        sigset_t sigset;
        struct kvm_vcpu_stat stat;
@@ -390,7 +390,7 @@ struct kvm {
        spinlock_t mmu_lock;
        struct mutex slots_lock;
        struct mm_struct *mm; /* userspace tied to this vm */
-       struct kvm_memslots *memslots[KVM_ADDRESS_SPACE_NUM];
+       struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
        struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
 
        /*
@@ -404,7 +404,7 @@ struct kvm {
        int last_boosted_vcpu;
        struct list_head vm_list;
        struct mutex lock;
-       struct kvm_io_bus *buses[KVM_NR_BUSES];
+       struct kvm_io_bus __rcu *buses[KVM_NR_BUSES];
 #ifdef CONFIG_HAVE_KVM_EVENTFD
        struct {
                spinlock_t        lock;
@@ -473,6 +473,12 @@ struct kvm {
 #define vcpu_err(vcpu, fmt, ...)                                       \
        kvm_err("vcpu%i " fmt, (vcpu)->vcpu_id, ## __VA_ARGS__)
 
+static inline struct kvm_io_bus *kvm_get_bus(struct kvm *kvm, enum kvm_bus idx)
+{
+       return srcu_dereference_check(kvm->buses[idx], &kvm->srcu,
+                                     lockdep_is_held(&kvm->slots_lock));
+}
+
 static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
 {
        /* Pairs with smp_wmb() in kvm_vm_ioctl_create_vcpu, in case
@@ -562,9 +568,8 @@ void kvm_put_kvm(struct kvm *kvm);
 
 static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id)
 {
-       return rcu_dereference_check(kvm->memslots[as_id],
-                       srcu_read_lock_held(&kvm->srcu)
-                       || lockdep_is_held(&kvm->slots_lock));
+       return srcu_dereference_check(kvm->memslots[as_id], &kvm->srcu,
+                       lockdep_is_held(&kvm->slots_lock));
 }
 
 static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 9120edf..f2ac53a 100644 (file)
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -825,7 +825,7 @@ static int kvm_assign_ioeventfd_idx(struct kvm *kvm,
        if (ret < 0)
                goto unlock_fail;
 
-       kvm->buses[bus_idx]->ioeventfd_count++;
+       kvm_get_bus(kvm, bus_idx)->ioeventfd_count++;
        list_add_tail(&p->list, &kvm->ioeventfds);
 
        mutex_unlock(&kvm->slots_lock);
@@ -848,6 +848,7 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
 {
        struct _ioeventfd        *p, *tmp;
        struct eventfd_ctx       *eventfd;
+       struct kvm_io_bus        *bus;
        int                       ret = -ENOENT;
 
        eventfd = eventfd_ctx_fdget(args->fd);
@@ -870,8 +871,9 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
                        continue;
 
                kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
-               if (kvm->buses[bus_idx])
-                       kvm->buses[bus_idx]->ioeventfd_count--;
+               bus = kvm_get_bus(kvm, bus_idx);
+               if (bus)
+                       bus->ioeventfd_count--;
                ioeventfd_release(p);
                ret = 0;
                break;

diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 31e40c9..b1286c4 100644 (file)
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -230,7 +230,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
        }
 
        mutex_lock(&kvm->irq_lock);
-       old = kvm->irq_routing;
+       old = rcu_dereference_protected(kvm->irq_routing, 1);
        rcu_assign_pointer(kvm->irq_routing, new);
        kvm_irq_routing_update(kvm);
        kvm_arch_irq_routing_update(kvm);

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 0d796c9..7766c2b 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -299,7 +299,12 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_init);
 
 void kvm_vcpu_uninit(struct kvm_vcpu *vcpu)
 {
-       put_pid(vcpu->pid);
+       /*
+        * no need for rcu_read_lock as VCPU_RUN is the only place that
+        * will change the vcpu->pid pointer and on uninit all file
+        * descriptors are already gone.
+        */
+       put_pid(rcu_dereference_protected(vcpu->pid, 1));
        kvm_arch_vcpu_uninit(vcpu);
        free_page((unsigned long)vcpu->run);
 }
@@ -680,8 +685,8 @@ static struct kvm *kvm_create_vm(unsigned long type)
        if (init_srcu_struct(&kvm->irq_srcu))
                goto out_err_no_irq_srcu;
        for (i = 0; i < KVM_NR_BUSES; i++) {
-               kvm->buses[i] = kzalloc(sizeof(struct kvm_io_bus),
-                                       GFP_KERNEL);
+               rcu_assign_pointer(kvm->buses[i],
+                       kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL));
                if (!kvm->buses[i])
                        goto out_err;
        }
@@ -706,9 +711,10 @@ out_err_no_srcu:
        hardware_disable_all();
 out_err_no_disable:
        for (i = 0; i < KVM_NR_BUSES; i++)
-               kfree(kvm->buses[i]);
+               kfree(rcu_access_pointer(kvm->buses[i]));
        for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
-               kvm_free_memslots(kvm, kvm->memslots[i]);
+               kvm_free_memslots(kvm,
+                       rcu_dereference_protected(kvm->memslots[i], 1));
        kvm_arch_free_vm(kvm);
        mmdrop(current->mm);
        return ERR_PTR(r);
@@ -741,8 +747,11 @@ static void kvm_destroy_vm(struct kvm *kvm)
        spin_unlock(&kvm_lock);
        kvm_free_irq_routing(kvm);
        for (i = 0; i < KVM_NR_BUSES; i++) {
-               if (kvm->buses[i])
-                       kvm_io_bus_destroy(kvm->buses[i]);
+               struct kvm_io_bus *bus;
+
+               bus = rcu_dereference_protected(kvm->buses[i], 1);
+               if (bus)
+                       kvm_io_bus_destroy(bus);
                kvm->buses[i] = NULL;
        }
        kvm_coalesced_mmio_free(kvm);
@@ -754,7 +763,8 @@ static void kvm_destroy_vm(struct kvm *kvm)
        kvm_arch_destroy_vm(kvm);
        kvm_destroy_devices(kvm);
        for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
-               kvm_free_memslots(kvm, kvm->memslots[i]);
+               kvm_free_memslots(kvm,
+                       rcu_dereference_protected(kvm->memslots[i], 1));
        cleanup_srcu_struct(&kvm->irq_srcu);
        cleanup_srcu_struct(&kvm->srcu);
        kvm_arch_free_vm(kvm);
@@ -2557,13 +2567,14 @@ static long kvm_vcpu_ioctl(struct file *filp,
        if (r)
                return r;
        switch (ioctl) {
-       case KVM_RUN:
+       case KVM_RUN: {
+               struct pid *oldpid;
                r = -EINVAL;
                if (arg)
                        goto out;
-               if (unlikely(vcpu->pid != current->pids[PIDTYPE_PID].pid)) {
+               oldpid = rcu_access_pointer(vcpu->pid);
+               if (unlikely(oldpid != current->pids[PIDTYPE_PID].pid)) {
                        /* The thread running this VCPU changed. */
-                       struct pid *oldpid = vcpu->pid;
                        struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
 
                        rcu_assign_pointer(vcpu->pid, newpid);
@@ -2574,6 +2585,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
                r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
                trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
                break;
+       }
        case KVM_GET_REGS: {
                struct kvm_regs *kvm_regs;
 
@@ -3569,7 +3581,7 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 {
        struct kvm_io_bus *new_bus, *bus;
 
-       bus = kvm->buses[bus_idx];
+       bus = kvm_get_bus(kvm, bus_idx);
        if (!bus)
                return -ENOMEM;
 
@@ -3598,7 +3610,7 @@ void kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
        int i;
        struct kvm_io_bus *new_bus, *bus;
 
-       bus = kvm->buses[bus_idx];
+       bus = kvm_get_bus(kvm, bus_idx);
        if (!bus)
                return;