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-rw-r--r--include/linux/kvm_host.h17
-rw-r--r--virt/kvm/eventfd.c8
-rw-r--r--virt/kvm/irqchip.c2
-rw-r--r--virt/kvm/kvm_main.c38
4 files changed, 42 insertions, 23 deletions
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 0b50e7b35ed4..648b34cabb38 100644
--- 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 9120edf3c94b..f2ac53ab8243 100644
--- 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 31e40c9e81df..b1286c4e0712 100644
--- 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 0d796c9a6482..7766c2b52797 100644
--- 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;
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-23 00:58:31 +0000