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                         rseq_handle_notify_resume(NULL, NULL);
  25                 }
  26
  27                 ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
  28                 if (ret)
  29                         return ret;
  30
  31                 ti_work = READ_ONCE(current_thread_info()->flags);
  32         } while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched());
  33         return 0;
  34 }
  35
  36 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
  37 {
  38         unsigned long ti_work;
  39
  40         /*
  41          * This is invoked from the outer guest loop with interrupts and
  42          * preemption enabled.
  43          *
  44          * KVM invokes xfer_to_guest_mode_work_pending() with interrupts
  45          * disabled in the inner loop before going into guest mode. No need
  46          * to disable interrupts here.
  47          */
  48         ti_work = READ_ONCE(current_thread_info()->flags);
  49         if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
  50                 return 0;
  51
  52         return xfer_to_guest_mode_work(vcpu, ti_work);
  53 }
  54 EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);