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