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                         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);