xref: /openbmc/linux/kernel/entry/kvm.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/entry-kvm.h>
4 #include <linux/kvm_host.h>
5 
6 static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
7 {
8 	do {
9 		int ret;
10 
11 		if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
12 			kvm_handle_signal_exit(vcpu);
13 			return -EINTR;
14 		}
15 
16 		if (ti_work & _TIF_NEED_RESCHED)
17 			schedule();
18 
19 		if (ti_work & _TIF_NOTIFY_RESUME)
20 			resume_user_mode_work(NULL);
21 
22 		ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
23 		if (ret)
24 			return ret;
25 
26 		ti_work = read_thread_flags();
27 	} while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched());
28 	return 0;
29 }
30 
31 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
32 {
33 	unsigned long ti_work;
34 
35 	/*
36 	 * This is invoked from the outer guest loop with interrupts and
37 	 * preemption enabled.
38 	 *
39 	 * KVM invokes xfer_to_guest_mode_work_pending() with interrupts
40 	 * disabled in the inner loop before going into guest mode. No need
41 	 * to disable interrupts here.
42 	 */
43 	ti_work = read_thread_flags();
44 	if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
45 		return 0;
46 
47 	return xfer_to_guest_mode_work(vcpu, ti_work);
48 }
49 EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
50