kernel/entry/virt.c

Source file repositories/reference/linux-study-clean/kernel/entry/virt.c

File Facts

System
Linux kernel
Corpus path
kernel/entry/virt.c
Extension
.c
Size
1063 bytes
Lines
47
Domain
Core OS
Bucket
Scheduler, Processes, Timers, Sync, And Syscalls
Inferred role
Core OS: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

#include <linux/entry-virt.h>

static int xfer_to_guest_mode_work(unsigned long ti_work)
{
	do {
		int ret;

		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
			return -EINTR;

		if (ti_work & (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY))
			schedule();

		if (ti_work & _TIF_NOTIFY_RESUME)
			resume_user_mode_work(NULL);

		ret = arch_xfer_to_guest_mode_handle_work(ti_work);
		if (ret)
			return ret;

		ti_work = read_thread_flags();
	} while (ti_work & XFER_TO_GUEST_MODE_WORK);
	return 0;
}

int xfer_to_guest_mode_handle_work(void)
{
	unsigned long ti_work;

	/*
	 * This is invoked from the outer guest loop with interrupts and
	 * preemption enabled.
	 *
	 * KVM invokes xfer_to_guest_mode_work_pending() with interrupts
	 * disabled in the inner loop before going into guest mode. No need
	 * to disable interrupts here.
	 */
	ti_work = read_thread_flags();
	if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
		return 0;

	return xfer_to_guest_mode_work(ti_work);
}
EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);

Annotation

Implementation Notes