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