virt/kvm/kvm_main.c

Source file repositories/reference/linux-study-clean/virt/kvm/kvm_main.c

File Facts

System
Linux kernel
Corpus path
virt/kvm/kvm_main.c
Extension
.c
Size
171203 bytes
Lines
6597
Domain
Kernel Services
Bucket
virt
Inferred role
Kernel Services: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

static const struct file_operations stat_fops_per_vm;

static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
			   unsigned long arg);
#ifdef CONFIG_KVM_COMPAT
static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl,
				  unsigned long arg);
#define KVM_COMPAT(c)	.compat_ioctl	= (c)
#else
/*
 * For architectures that don't implement a compat infrastructure,
 * adopt a double line of defense:
 * - Prevent a compat task from opening /dev/kvm
 * - If the open has been done by a 64bit task, and the KVM fd
 *   passed to a compat task, let the ioctls fail.
 */
static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl,
				unsigned long arg) { return -EINVAL; }

static int kvm_no_compat_open(struct inode *inode, struct file *file)
{
	return is_compat_task() ? -ENODEV : 0;
}
#define KVM_COMPAT(c)	.compat_ioctl	= kvm_no_compat_ioctl,	\
			.open		= kvm_no_compat_open
#endif

static void kvm_io_bus_destroy(struct kvm_io_bus *bus);

#define KVM_EVENT_CREATE_VM 0
#define KVM_EVENT_DESTROY_VM 1
static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
static unsigned long long kvm_createvm_count;
static unsigned long long kvm_active_vms;

static DEFINE_PER_CPU(cpumask_var_t, cpu_kick_mask);

__weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm)
{
}

/*
 * Switches to specified vcpu, until a matching vcpu_put()
 */
void vcpu_load(struct kvm_vcpu *vcpu)
{
	int cpu = get_cpu();

	__this_cpu_write(kvm_running_vcpu, vcpu);
	preempt_notifier_register(&vcpu->preempt_notifier);
	kvm_arch_vcpu_load(vcpu, cpu);
	put_cpu();
}
EXPORT_SYMBOL_FOR_KVM_INTERNAL(vcpu_load);

void vcpu_put(struct kvm_vcpu *vcpu)
{
	preempt_disable();
	kvm_arch_vcpu_put(vcpu);
	preempt_notifier_unregister(&vcpu->preempt_notifier);
	__this_cpu_write(kvm_running_vcpu, NULL);
	preempt_enable();
}
EXPORT_SYMBOL_FOR_KVM_INTERNAL(vcpu_put);

/* TODO: merge with kvm_arch_vcpu_should_kick */
static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req)
{
	int mode = kvm_vcpu_exiting_guest_mode(vcpu);

	/*
	 * We need to wait for the VCPU to reenable interrupts and get out of
	 * READING_SHADOW_PAGE_TABLES mode.
	 */
	if (req & KVM_REQUEST_WAIT)
		return mode != OUTSIDE_GUEST_MODE;

	/*
	 * Need to kick a running VCPU, but otherwise there is nothing to do.
	 */
	return mode == IN_GUEST_MODE;
}

static void ack_kick(void *_completed)
{
}

static inline bool kvm_kick_many_cpus(struct cpumask *cpus, bool wait)
{
	if (cpumask_empty(cpus))

Annotation

Implementation Notes