arch/s390/include/asm/kvm_para.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * definition for paravirtual devices on s390
   4  *
   5  * Copyright IBM Corp. 2008
   6  *
   7  *    Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
   8  */
   9 /*
  10  * Hypercalls for KVM on s390. The calling convention is similar to the
  11  * s390 ABI, so we use R2-R6 for parameters 1-5. In addition we use R1
  12  * as hypercall number and R7 as parameter 6. The return value is
  13  * written to R2. We use the diagnose instruction as hypercall. To avoid
  14  * conflicts with existing diagnoses for LPAR and z/VM, we do not use
  15  * the instruction encoded number, but specify the number in R1 and
  16  * use 0x500 as KVM hypercall
  17  *
  18  * Copyright IBM Corp. 2007,2008
  19  * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  20  */
  21 #ifndef __S390_KVM_PARA_H
  22 #define __S390_KVM_PARA_H
  23
  24 #include <uapi/asm/kvm_para.h>
  25 #include <asm/diag.h>
  26
  27 #define HYPERCALL_FMT_0
  28 #define HYPERCALL_FMT_1 , "0" (r2)
  29 #define HYPERCALL_FMT_2 , "d" (r3) HYPERCALL_FMT_1
  30 #define HYPERCALL_FMT_3 , "d" (r4) HYPERCALL_FMT_2
  31 #define HYPERCALL_FMT_4 , "d" (r5) HYPERCALL_FMT_3
  32 #define HYPERCALL_FMT_5 , "d" (r6) HYPERCALL_FMT_4
  33 #define HYPERCALL_FMT_6 , "d" (r7) HYPERCALL_FMT_5
  34
  35 #define HYPERCALL_PARM_0
  36 #define HYPERCALL_PARM_1 , unsigned long arg1
  37 #define HYPERCALL_PARM_2 HYPERCALL_PARM_1, unsigned long arg2
  38 #define HYPERCALL_PARM_3 HYPERCALL_PARM_2, unsigned long arg3
  39 #define HYPERCALL_PARM_4 HYPERCALL_PARM_3, unsigned long arg4
  40 #define HYPERCALL_PARM_5 HYPERCALL_PARM_4, unsigned long arg5
  41 #define HYPERCALL_PARM_6 HYPERCALL_PARM_5, unsigned long arg6
  42
  43 #define HYPERCALL_REGS_0
  44 #define HYPERCALL_REGS_1                                                \
  45         register unsigned long r2 asm("2") = arg1
  46 #define HYPERCALL_REGS_2                                                \
  47         HYPERCALL_REGS_1;                                               \
  48         register unsigned long r3 asm("3") = arg2
  49 #define HYPERCALL_REGS_3                                                \
  50         HYPERCALL_REGS_2;                                               \
  51         register unsigned long r4 asm("4") = arg3
  52 #define HYPERCALL_REGS_4                                                \
  53         HYPERCALL_REGS_3;                                               \
  54         register unsigned long r5 asm("5") = arg4
  55 #define HYPERCALL_REGS_5                                                \
  56         HYPERCALL_REGS_4;                                               \
  57         register unsigned long r6 asm("6") = arg5
  58 #define HYPERCALL_REGS_6                                                \
  59         HYPERCALL_REGS_5;                                               \
  60         register unsigned long r7 asm("7") = arg6
  61
  62 #define HYPERCALL_ARGS_0
  63 #define HYPERCALL_ARGS_1 , arg1
  64 #define HYPERCALL_ARGS_2 HYPERCALL_ARGS_1, arg2
  65 #define HYPERCALL_ARGS_3 HYPERCALL_ARGS_2, arg3
  66 #define HYPERCALL_ARGS_4 HYPERCALL_ARGS_3, arg4
  67 #define HYPERCALL_ARGS_5 HYPERCALL_ARGS_4, arg5
  68 #define HYPERCALL_ARGS_6 HYPERCALL_ARGS_5, arg6
  69
  70 #define GENERATE_KVM_HYPERCALL_FUNC(args)                               \
  71 static inline                                                           \
  72 long __kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)      \
  73 {                                                                       \
  74         register unsigned long __nr asm("1") = nr;                      \
  75         register long __rc asm("2");                                    \
  76         HYPERCALL_REGS_##args;                                          \
  77                                                                         \
  78         asm volatile (                                                  \
  79                 "       diag    2,4,0x500\n"                            \
  80                 : "=d" (__rc)                                           \
  81                 : "d" (__nr) HYPERCALL_FMT_##args                       \
  82                 : "memory", "cc");                                      \
  83         return __rc;                                                    \
  84 }                                                                       \
  85                                                                         \
  86 static inline                                                           \
  87 long kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)        \
  88 {                                                                       \
  89         diag_stat_inc(DIAG_STAT_X500);                                  \
  90         return __kvm_hypercall##args(nr HYPERCALL_ARGS_##args);         \
  91 }
  92
  93 GENERATE_KVM_HYPERCALL_FUNC(0)
  94 GENERATE_KVM_HYPERCALL_FUNC(1)
  95 GENERATE_KVM_HYPERCALL_FUNC(2)
  96 GENERATE_KVM_HYPERCALL_FUNC(3)
  97 GENERATE_KVM_HYPERCALL_FUNC(4)
  98 GENERATE_KVM_HYPERCALL_FUNC(5)
  99 GENERATE_KVM_HYPERCALL_FUNC(6)
 100
 101 /* kvm on s390 is always paravirtualization enabled */
 102 static inline int kvm_para_available(void)
 103 {
 104         return 1;
 105 }
 106
 107 /* No feature bits are currently assigned for kvm on s390 */
 108 static inline unsigned int kvm_arch_para_features(void)
 109 {
 110         return 0;
 111 }
 112
 113 static inline unsigned int kvm_arch_para_hints(void)
 114 {
 115         return 0;
 116 }
 117
 118 static inline bool kvm_check_and_clear_guest_paused(void)
 119 {
 120         return false;
 121 }
 122
 123 #endif /* __S390_KVM_PARA_H */