1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Snippet definitions
4 *
5 * Copyright IBM Corp. 2021
6 * Author: Janosch Frank <frankja@linux.ibm.com>
7 */
8
9 #ifndef _S390X_SNIPPET_H_
10 #define _S390X_SNIPPET_H_
11
12 #include <sie.h>
13 #include <uv.h>
14 #include <asm/uv.h>
15
16 /* This macro cuts down the length of the pointers to snippets */
17 #define SNIPPET_NAME_START(type, file) \
18 _binary_s390x_snippets_##type##_##file##_gbin_start
19 #define SNIPPET_NAME_END(type, file) \
20 _binary_s390x_snippets_##type##_##file##_gbin_end
21 #define SNIPPET_HDR_START(type, file) \
22 _binary_s390x_snippets_##type##_##file##_hdr_start
23 #define SNIPPET_HDR_END(type, file) \
24 _binary_s390x_snippets_##type##_##file##_hdr_end
25
26
27 /* Returns the length of the snippet */
28 #define SNIPPET_LEN(type, file) \
29 ((uintptr_t)SNIPPET_NAME_END(type, file) - (uintptr_t)SNIPPET_NAME_START(type, file))
30 #define SNIPPET_HDR_LEN(type, file) \
31 ((uintptr_t)SNIPPET_HDR_END(type, file) - (uintptr_t)SNIPPET_HDR_START(type, file))
32
33 /*
34 * Some of the UV memory needs to be allocated with >31 bit
35 * addresses which means we need a lot more memory than other
36 * tests.
37 */
38 #define SNIPPET_PV_MIN_MEM_SIZE (SZ_1M * 2200UL)
39
40 #define SNIPPET_PV_TWEAK0 0x42UL
41 #define SNIPPET_PV_TWEAK1 0UL
42 #define SNIPPET_UNPACK_OFF 0
43
44
45 /*
46 * C snippet instructions start at 0x4000 due to the prefix and the
47 * stack being before that. ASM snippets don't strictly need a stack
48 * but keeping the starting address the same means less code.
49 */
50 #define SNIPPET_ENTRY_ADDR 0x4000
51
52 /* Standard entry PSWs for snippets which can simply be copied into the guest PSW */
53 static const struct psw snippet_psw = {
54 .mask = PSW_MASK_64,
55 .addr = SNIPPET_ENTRY_ADDR,
56 };
57
58 /*
59 * Sets up a snippet guest on top of an existing and initialized SIE
60 * vm struct.
61 * Once this function has finished without errors the guest can be started.
62 *
63 * @vm: VM that this function will populated, has to be initialized already
64 * @gbin: Snippet gbin data pointer
65 * @gbin_len: Length of the gbin data
66 * @off: Offset from guest absolute 0x0 where snippet is copied to
67 */
snippet_init(struct vm * vm,const char * gbin,uint64_t gbin_len,uint64_t off)68 static inline void snippet_init(struct vm *vm, const char *gbin,
69 uint64_t gbin_len, uint64_t off)
70 {
71 uint64_t mso = vm->sblk->mso;
72
73 /* Copy test image to guest memory */
74 memcpy((void *)mso + off, gbin, gbin_len);
75
76 /* Setup guest PSW */
77 vm->sblk->gpsw = snippet_psw;
78
79 /*
80 * We want to exit on PGM exceptions so we don't need
81 * exception handlers in the guest.
82 */
83 vm->sblk->ictl = ICTL_OPEREXC | ICTL_PINT;
84 }
85
86 /*
87 * Sets up a snippet UV/PV guest on top of an existing and initialized
88 * SIE vm struct.
89 * Once this function has finished without errors the guest can be started.
90 *
91 * @vm: VM that this function will populated, has to be initialized already
92 * @gbin: Snippet gbin data pointer
93 * @hdr: Snippet SE header data pointer
94 * @gbin_len: Length of the gbin data
95 * @hdr_len: Length of the hdr data
96 * @off: Offset from guest absolute 0x0 where snippet is copied to
97 */
snippet_pv_init(struct vm * vm,const char * gbin,const char * hdr,uint64_t gbin_len,uint64_t hdr_len,uint64_t off)98 static inline void snippet_pv_init(struct vm *vm, const char *gbin,
99 const char *hdr, uint64_t gbin_len,
100 uint64_t hdr_len, uint64_t off)
101 {
102 uint64_t tweak[2] = {SNIPPET_PV_TWEAK0, SNIPPET_PV_TWEAK1};
103 uint64_t mso = vm->sblk->mso;
104 int i;
105
106 snippet_init(vm, gbin, gbin_len, off);
107
108 uv_create_guest(vm);
109 uv_set_se_hdr(vm->uv.vm_handle, (void *)hdr, hdr_len);
110
111 /* Unpack works on guest addresses so we only need off */
112 uv_unpack(vm, off, gbin_len, tweak[0]);
113 uv_verify_load(vm);
114
115 /*
116 * Manually import:
117 * - lowcore 0x0 - 0x1000 (asm)
118 * - stack 0x3000 (C)
119 */
120 for (i = 0; i < 4; i++) {
121 uv_import(vm->uv.vm_handle, mso + PAGE_SIZE * i);
122 }
123 }
124
125 /* Allocates and sets up a snippet based guest */
snippet_setup_guest(struct vm * vm,bool is_pv)126 static inline void snippet_setup_guest(struct vm *vm, bool is_pv)
127 {
128 const unsigned long guest_size = SZ_1M;
129 uint8_t *guest_start = sie_guest_alloc(guest_size);
130
131 /* Initialize the vm struct and allocate control blocks */
132 sie_guest_create(vm, (uint64_t)guest_start, guest_size);
133
134 if (is_pv) {
135 /* FMT4 needs a ESCA */
136 sie_guest_sca_create(vm);
137
138 /*
139 * Initialize UV and setup the address spaces needed
140 * to run a PV guest.
141 */
142 uv_init();
143 uv_setup_asces();
144 }
145 }
146
147 #endif
148