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 , "" (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 */
124
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