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/static_call_types.h>
   6 #include <linux/resume_user_mode.h>
   7 #include <linux/syscalls.h>
   8 #include <linux/seccomp.h>
   9 #include <linux/sched.h>
  10 #include <linux/tick.h>
  11
  12 /* Transfer to guest mode work */
  13 #ifdef CONFIG_KVM_XFER_TO_GUEST_WORK
  14
  15 #ifndef ARCH_XFER_TO_GUEST_MODE_WORK
  16 # define ARCH_XFER_TO_GUEST_MODE_WORK   (0)
  17 #endif
  18
  19 #define XFER_TO_GUEST_MODE_WORK                                         \
  20         (_TIF_NEED_RESCHED | _TIF_NEED_RESCHED_LAZY | _TIF_SIGPENDING | \
  21          _TIF_NOTIFY_SIGNAL | _TIF_NOTIFY_RESUME |                      \
  22          ARCH_XFER_TO_GUEST_MODE_WORK)
  23
  24 struct kvm_vcpu;
  25
  26 /**
  27  * arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
  28  *                                       mode work handling function.
  29  * @vcpu:       Pointer to current's VCPU data
  30  * @ti_work:    Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
  31  *
  32  * Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
  33  * replaced by architecture specific code.
  34  */
  35 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
  36                                                       unsigned long ti_work);
  37
  38 #ifndef arch_xfer_to_guest_mode_work
  39 static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
  40                                                       unsigned long ti_work)
  41 {
  42         return 0;
  43 }
  44 #endif
  45
  46 /**
  47  * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
  48  *                                  to be handled before going to guest mode
  49  * @vcpu:       Pointer to current's VCPU data
  50  *
  51  * Returns: 0 or an error code
  52  */
  53 int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
  54
  55 /**
  56  * xfer_to_guest_mode_prepare - Perform last minute preparation work that
  57  *                              need to be handled while IRQs are disabled
  58  *                              upon entering to guest.
  59  *
  60  * Has to be invoked with interrupts disabled before the last call
  61  * to xfer_to_guest_mode_work_pending().
  62  */
  63 static inline void xfer_to_guest_mode_prepare(void)
  64 {
  65         lockdep_assert_irqs_disabled();
  66         tick_nohz_user_enter_prepare();
  67 }
  68
  69 /**
  70  * __xfer_to_guest_mode_work_pending - Check if work is pending
  71  *
  72  * Returns: True if work pending, False otherwise.
  73  *
  74  * Bare variant of xfer_to_guest_mode_work_pending(). Can be called from
  75  * interrupt enabled code for racy quick checks with care.
  76  */
  77 static inline bool __xfer_to_guest_mode_work_pending(void)
  78 {
  79         unsigned long ti_work = read_thread_flags();
  80
  81         return !!(ti_work & XFER_TO_GUEST_MODE_WORK);
  82 }
  83
  84 /**
  85  * xfer_to_guest_mode_work_pending - Check if work is pending which needs to be
  86  *                                   handled before returning to guest mode
  87  *
  88  * Returns: True if work pending, False otherwise.
  89  *
  90  * Has to be invoked with interrupts disabled before the transition to
  91  * guest mode.
  92  */
  93 static inline bool xfer_to_guest_mode_work_pending(void)
  94 {
  95         lockdep_assert_irqs_disabled();
  96         return __xfer_to_guest_mode_work_pending();
  97 }
  98 #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
  99
 100 #endif