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-rw-r--r--virt/kvm/kvm_main.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2079d6065795..540e2bbf00f7 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -5184,7 +5184,20 @@ 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 +5210,8 @@ 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);