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Diffstat (limited to 'virt/kvm/kvm_main.c')
-rw-r--r--virt/kvm/kvm_main.c59
1 files changed, 37 insertions, 22 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cb5c13eee193..479802a892d4 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3962,18 +3962,19 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
}
vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus);
- r = xa_insert(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, GFP_KERNEL_ACCOUNT);
- BUG_ON(r == -EBUSY);
+ r = xa_reserve(&kvm->vcpu_array, vcpu->vcpu_idx, GFP_KERNEL_ACCOUNT);
if (r)
goto unlock_vcpu_destroy;
/* Now it's all set up, let userspace reach it */
kvm_get_kvm(kvm);
r = create_vcpu_fd(vcpu);
- if (r < 0) {
- xa_erase(&kvm->vcpu_array, vcpu->vcpu_idx);
- kvm_put_kvm_no_destroy(kvm);
- goto unlock_vcpu_destroy;
+ if (r < 0)
+ goto kvm_put_xa_release;
+
+ if (KVM_BUG_ON(!!xa_store(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, 0), kvm)) {
+ r = -EINVAL;
+ goto kvm_put_xa_release;
}
/*
@@ -3988,6 +3989,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
kvm_create_vcpu_debugfs(vcpu);
return r;
+kvm_put_xa_release:
+ kvm_put_kvm_no_destroy(kvm);
+ xa_release(&kvm->vcpu_array, vcpu->vcpu_idx);
unlock_vcpu_destroy:
mutex_unlock(&kvm->lock);
kvm_dirty_ring_free(&vcpu->dirty_ring);
@@ -5184,7 +5188,20 @@ static void hardware_disable_all(void)
static int hardware_enable_all(void)
{
atomic_t failed = ATOMIC_INIT(0);
- int r = 0;
+ int r;
+
+ /*
+ * Do not enable hardware virtualization if the system is going down.
+ * If userspace initiated a forced reboot, e.g. reboot -f, then it's
+ * possible for an in-flight KVM_CREATE_VM to trigger hardware enabling
+ * after kvm_reboot() is called. Note, this relies on system_state
+ * being set _before_ kvm_reboot(), which is why KVM uses a syscore ops
+ * hook instead of registering a dedicated reboot notifier (the latter
+ * runs before system_state is updated).
+ */
+ if (system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF ||
+ system_state == SYSTEM_RESTART)
+ return -EBUSY;
/*
* When onlining a CPU, cpu_online_mask is set before kvm_online_cpu()
@@ -5197,6 +5214,8 @@ static int hardware_enable_all(void)
cpus_read_lock();
mutex_lock(&kvm_lock);
+ r = 0;
+
kvm_usage_count++;
if (kvm_usage_count == 1) {
on_each_cpu(hardware_enable_nolock, &failed, 1);
@@ -5213,26 +5232,24 @@ static int hardware_enable_all(void)
return r;
}
-static int kvm_reboot(struct notifier_block *notifier, unsigned long val,
- void *v)
+static void kvm_shutdown(void)
{
/*
- * Some (well, at least mine) BIOSes hang on reboot if
- * in vmx root mode.
- *
- * And Intel TXT required VMX off for all cpu when system shutdown.
+ * Disable hardware virtualization and set kvm_rebooting to indicate
+ * that KVM has asynchronously disabled hardware virtualization, i.e.
+ * that relevant errors and exceptions aren't entirely unexpected.
+ * Some flavors of hardware virtualization need to be disabled before
+ * transferring control to firmware (to perform shutdown/reboot), e.g.
+ * on x86, virtualization can block INIT interrupts, which are used by
+ * firmware to pull APs back under firmware control. Note, this path
+ * is used for both shutdown and reboot scenarios, i.e. neither name is
+ * 100% comprehensive.
*/
pr_info("kvm: exiting hardware virtualization\n");
kvm_rebooting = true;
on_each_cpu(hardware_disable_nolock, NULL, 1);
- return NOTIFY_OK;
}
-static struct notifier_block kvm_reboot_notifier = {
- .notifier_call = kvm_reboot,
- .priority = 0,
-};
-
static int kvm_suspend(void)
{
/*
@@ -5263,6 +5280,7 @@ static void kvm_resume(void)
static struct syscore_ops kvm_syscore_ops = {
.suspend = kvm_suspend,
.resume = kvm_resume,
+ .shutdown = kvm_shutdown,
};
#else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
static int hardware_enable_all(void)
@@ -5967,7 +5985,6 @@ int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
if (r)
return r;
- register_reboot_notifier(&kvm_reboot_notifier);
register_syscore_ops(&kvm_syscore_ops);
#endif
@@ -6039,7 +6056,6 @@ err_cpu_kick_mask:
err_vcpu_cache:
#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
unregister_syscore_ops(&kvm_syscore_ops);
- unregister_reboot_notifier(&kvm_reboot_notifier);
cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE);
#endif
return r;
@@ -6065,7 +6081,6 @@ void kvm_exit(void)
kvm_async_pf_deinit();
#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
unregister_syscore_ops(&kvm_syscore_ops);
- unregister_reboot_notifier(&kvm_reboot_notifier);
cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE);
#endif
kvm_irqfd_exit();