include/asm/kvm_para.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * definition for paravirtual devices on s390
0004  *
0005  * Copyright IBM Corp. 2008
0006  *
0007  *    Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
0008  */
0009 /*
0010  * Hypercalls for KVM on s390. The calling convention is similar to the
0011  * s390 ABI, so we use R2-R6 for parameters 1-5. In addition we use R1
0012  * as hypercall number and R7 as parameter 6. The return value is
0013  * written to R2. We use the diagnose instruction as hypercall. To avoid
0014  * conflicts with existing diagnoses for LPAR and z/VM, we do not use
0015  * the instruction encoded number, but specify the number in R1 and
0016  * use 0x500 as KVM hypercall
0017  *
0018  * Copyright IBM Corp. 2007,2008
0019  * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
0020  */
0021 #ifndef __S390_KVM_PARA_H
0022 #define __S390_KVM_PARA_H
0023
0024 #include <uapi/asm/kvm_para.h>
0025 #include <asm/diag.h>
0026
0027 #define HYPERCALL_FMT_0
0028 #define HYPERCALL_FMT_1 , "0" (r2)
0029 #define HYPERCALL_FMT_2 , "d" (r3) HYPERCALL_FMT_1
0030 #define HYPERCALL_FMT_3 , "d" (r4) HYPERCALL_FMT_2
0031 #define HYPERCALL_FMT_4 , "d" (r5) HYPERCALL_FMT_3
0032 #define HYPERCALL_FMT_5 , "d" (r6) HYPERCALL_FMT_4
0033 #define HYPERCALL_FMT_6 , "d" (r7) HYPERCALL_FMT_5
0034
0035 #define HYPERCALL_PARM_0
0036 #define HYPERCALL_PARM_1 , unsigned long arg1
0037 #define HYPERCALL_PARM_2 HYPERCALL_PARM_1, unsigned long arg2
0038 #define HYPERCALL_PARM_3 HYPERCALL_PARM_2, unsigned long arg3
0039 #define HYPERCALL_PARM_4 HYPERCALL_PARM_3, unsigned long arg4
0040 #define HYPERCALL_PARM_5 HYPERCALL_PARM_4, unsigned long arg5
0041 #define HYPERCALL_PARM_6 HYPERCALL_PARM_5, unsigned long arg6
0042
0043 #define HYPERCALL_REGS_0
0044 #define HYPERCALL_REGS_1                        \
0045     register unsigned long r2 asm("2") = arg1
0046 #define HYPERCALL_REGS_2                        \
0047     HYPERCALL_REGS_1;                       \
0048     register unsigned long r3 asm("3") = arg2
0049 #define HYPERCALL_REGS_3                        \
0050     HYPERCALL_REGS_2;                       \
0051     register unsigned long r4 asm("4") = arg3
0052 #define HYPERCALL_REGS_4                        \
0053     HYPERCALL_REGS_3;                       \
0054     register unsigned long r5 asm("5") = arg4
0055 #define HYPERCALL_REGS_5                        \
0056     HYPERCALL_REGS_4;                       \
0057     register unsigned long r6 asm("6") = arg5
0058 #define HYPERCALL_REGS_6                        \
0059     HYPERCALL_REGS_5;                       \
0060     register unsigned long r7 asm("7") = arg6
0061
0062 #define HYPERCALL_ARGS_0
0063 #define HYPERCALL_ARGS_1 , arg1
0064 #define HYPERCALL_ARGS_2 HYPERCALL_ARGS_1, arg2
0065 #define HYPERCALL_ARGS_3 HYPERCALL_ARGS_2, arg3
0066 #define HYPERCALL_ARGS_4 HYPERCALL_ARGS_3, arg4
0067 #define HYPERCALL_ARGS_5 HYPERCALL_ARGS_4, arg5
0068 #define HYPERCALL_ARGS_6 HYPERCALL_ARGS_5, arg6
0069
0070 #define GENERATE_KVM_HYPERCALL_FUNC(args)               \
0071 static inline                               \
0072 long __kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)  \
0073 {                                   \
0074     register unsigned long __nr asm("1") = nr;          \
0075     register long __rc asm("2");                    \
0076     HYPERCALL_REGS_##args;                      \
0077                                     \
0078     asm volatile (                          \
0079         "   diag    2,4,0x500\n"                \
0080         : "=d" (__rc)                       \
0081         : "d" (__nr) HYPERCALL_FMT_##args           \
0082         : "memory", "cc");                  \
0083     return __rc;                            \
0084 }                                   \
0085                                     \
0086 static inline                               \
0087 long kvm_hypercall##args(unsigned long nr HYPERCALL_PARM_##args)    \
0088 {                                   \
0089     diag_stat_inc(DIAG_STAT_X500);                  \
0090     return __kvm_hypercall##args(nr HYPERCALL_ARGS_##args);     \
0091 }
0092
0093 GENERATE_KVM_HYPERCALL_FUNC(0)
0094 GENERATE_KVM_HYPERCALL_FUNC(1)
0095 GENERATE_KVM_HYPERCALL_FUNC(2)
0096 GENERATE_KVM_HYPERCALL_FUNC(3)
0097 GENERATE_KVM_HYPERCALL_FUNC(4)
0098 GENERATE_KVM_HYPERCALL_FUNC(5)
0099 GENERATE_KVM_HYPERCALL_FUNC(6)
0100
0101 /* kvm on s390 is always paravirtualization enabled */
0102 static inline int kvm_para_available(void)
0103 {
0104     return 1;
0105 }
0106
0107 /* No feature bits are currently assigned for kvm on s390 */
0108 static inline unsigned int kvm_arch_para_features(void)
0109 {
0110     return 0;
0111 }
0112
0113 static inline unsigned int kvm_arch_para_hints(void)
0114 {
0115     return 0;
0116 }
0117
0118 static inline bool kvm_check_and_clear_guest_paused(void)
0119 {
0120     return false;
0121 }
0122
0123 #endif /* __S390_KVM_PARA_H */