kernel/entry/kvm.c

   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                         clear_notify_signal();
  13                         if (task_work_pending(current))
  14                                 task_work_run();
  15                 }
  16
  17                 if (ti_work & _TIF_SIGPENDING) {
  18                         kvm_handle_signal_exit(vcpu);
  19                         return -EINTR;
  20                 }
  21
  22                 if (ti_work & _TIF_NEED_RESCHED)
  23                         schedule();
  24
  25                 if (ti_work & _TIF_NOTIFY_RESUME)
  26                         resume_user_mode_work(NULL);
  27
  28                 ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
  29                 if (ret)
  30                         return ret;
  31
  32                 ti_work = read_thread_flags();
  33         } while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched());
  34         return 0;
  35 }
  36
  37 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
  38 {
  39         unsigned long ti_work;
  40
  41         /*
  42          * This is invoked from the outer guest loop with interrupts and
  43          * preemption enabled.
  44          *
  45          * KVM invokes xfer_to_guest_mode_work_pending() with interrupts
  46          * disabled in the inner loop before going into guest mode. No need
  47          * to disable interrupts here.
  48          */
  49         ti_work = read_thread_flags();
  50         if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
  51                 return 0;
  52
  53         return xfer_to_guest_mode_work(vcpu, ti_work);
  54 }
  55 EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);