include/linux/entry-kvm.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_ENTRYKVM_H
   3 #define __LINUX_ENTRYKVM_H
   4
   5 #include <linux/entry-common.h>
   6 #include <linux/tick.h>
   7
   8 /* Transfer to guest mode work */
   9 #ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
  10
  11 #ifndef ARCH_XFER_TO_GUEST_MODE_WORK
  12 # define ARCH_XFER_TO_GUEST_MODE_WORK   (0)
  13 #endif
  14
  15 #define XFER_TO_GUEST_MODE_WORK                                         \
  16         (_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL |     \
  17          _TIF_NOTIFY_RESUME | ARCH_XFER_TO_GUEST_MODE_WORK)
  18
  19 struct kvm_vcpu;
  20
  21 /**
  22  * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
  23  *                                       mode work handling function.
  24  * @vcpu:       Pointer to current's VCPU data
  25  * @ti_work:    Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
  26  *
  27  * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
  28  * replaced by architecture specific code.
  29  */
  30 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
  31                                                       unsigned long ti_work);
  32
  33 #ifndef arch_xfer_to_guest_mode_work
  34 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
  35                                                       unsigned long ti_work)
  36 {
  37         return 0;
  38 }
  39 #endif
  40
  41 /**
  42  * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
  43  *                                  to be handled before going to guest mode
  44  * @vcpu:       Pointer to current's VCPU data
  45  *
  46  * Returns: 0 or an error code
  47  */
  48 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
  49
  50 /**
  51  * xfer_to_guest_mode_prepare - Perform last minute preparation work that
  52  *                              need to be handled while IRQs are disabled
  53  *                              upon entering to guest.
  54  *
  55  * Has to be invoked with interrupts disabled before the last call
  56  * to xfer_to_guest_mode_work_pending().
  57  */
  58 static inline void xfer_to_guest_mode_prepare(void)
  59 {
  60         lockdep_assert_irqs_disabled();
  61         tick_nohz_user_enter_prepare();
  62 }
  63
  64 /**
  65  * __xfer_to_guest_mode_work_pending - Check if work is pending
  66  *
  67  * Returns: True if work pending, False otherwise.
  68  *
  69  * Bare variant of xfer_to_guest_mode_work_pending(). Can be called from
  70  * interrupt enabled code for racy quick checks with care.
  71  */
  72 static inline bool __xfer_to_guest_mode_work_pending(void)
  73 {
  74         unsigned long ti_work = READ_ONCE(current_thread_info()->flags);
  75
  76         return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
  77 }
  78
  79 /**
  80  * xfer_to_guest_mode_work_pending - Check if work is pending which needs to be
  81  *                                   handled before returning to guest mode
  82  *
  83  * Returns: True if work pending, False otherwise.
  84  *
  85  * Has to be invoked with interrupts disabled before the transition to
  86  * guest mode.
  87  */
  88 static inline bool xfer_to_guest_mode_work_pending(void)
  89 {
  90         lockdep_assert_irqs_disabled();
  91         return __xfer_to_guest_mode_work_pending();
  92 }
  93 #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
  94
  95 #endif