xref: /kvm-unit-tests/s390x/mvpg-sie.c (revision aa8794b1414330760defc06633da32b462cb34be)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Tests mvpg SIE partial execution intercepts.
4  *
5  * Copyright 2021 IBM Corp.
6  *
7  * Authors:
8  *    Janosch Frank <frankja@linux.ibm.com>
9  */
10 #include <libcflat.h>
11 #include <asm/asm-offsets.h>
12 #include <asm-generic/barrier.h>
13 #include <asm/pgtable.h>
14 #include <mmu.h>
15 #include <asm/page.h>
16 #include <asm/facility.h>
17 #include <asm/mem.h>
18 #include <alloc_page.h>
19 #include <vm.h>
20 #include <sclp.h>
21 #include <sie.h>
22 
23 static u8 *guest;
24 static u8 *guest_instr;
25 static struct vm vm;
26 
27 static uint8_t *src;
28 static uint8_t *dst;
29 static uint8_t *cmp;
30 
31 extern const char _binary_s390x_snippets_c_mvpg_snippet_gbin_start[];
32 extern const char _binary_s390x_snippets_c_mvpg_snippet_gbin_end[];
33 int binary_size;
34 
35 static void sie(struct vm *vm)
36 {
37 	/* Reset icptcode so we don't trip over it below */
38 	vm->sblk->icptcode = 0;
39 
40 	while (vm->sblk->icptcode == 0) {
41 		sie64a(vm->sblk, &vm->save_area);
42 		assert(vm->sblk->icptcode != ICPT_VALIDITY);
43 	}
44 	vm->save_area.guest.grs[14] = vm->sblk->gg14;
45 	vm->save_area.guest.grs[15] = vm->sblk->gg15;
46 }
47 
48 static void test_mvpg_pei(void)
49 {
50 	uint64_t **pei_dst = (uint64_t **)((uintptr_t) vm.sblk + 0xc0);
51 	uint64_t **pei_src = (uint64_t **)((uintptr_t) vm.sblk + 0xc8);
52 
53 	report_prefix_push("pei");
54 
55 	report_prefix_push("src");
56 	memset(dst, 0, PAGE_SIZE);
57 	protect_page(src, PAGE_ENTRY_I);
58 	sie(&vm);
59 	report(vm.sblk->icptcode == ICPT_PARTEXEC, "Partial execution");
60 	report((uintptr_t)**pei_src == (uintptr_t)src + PAGE_ENTRY_I, "PEI_SRC correct");
61 	report((uintptr_t)**pei_dst == (uintptr_t)dst, "PEI_DST correct");
62 	unprotect_page(src, PAGE_ENTRY_I);
63 	report(!memcmp(cmp, dst, PAGE_SIZE), "Destination intact");
64 	/*
65 	 * We need to execute the diag44 which is used as a blocker
66 	 * behind the mvpg. It makes sure we fail the tests above if
67 	 * the mvpg wouldn't have intercepted.
68 	 */
69 	sie(&vm);
70 	/* Make sure we intercepted for the diag44 and nothing else */
71 	assert(vm.sblk->icptcode == ICPT_INST &&
72 	       vm.sblk->ipa == 0x8300 && vm.sblk->ipb == 0x440000);
73 	report_prefix_pop();
74 
75 	/* Clear PEI data for next check */
76 	report_prefix_push("dst");
77 	memset((uint64_t *)((uintptr_t) vm.sblk + 0xc0), 0, 16);
78 	memset(dst, 0, PAGE_SIZE);
79 	protect_page(dst, PAGE_ENTRY_I);
80 	sie(&vm);
81 	report(vm.sblk->icptcode == ICPT_PARTEXEC, "Partial execution");
82 	report((uintptr_t)**pei_src == (uintptr_t)src, "PEI_SRC correct");
83 	report((uintptr_t)**pei_dst == (uintptr_t)dst + PAGE_ENTRY_I, "PEI_DST correct");
84 	/* Needed for the memcmp and general cleanup */
85 	unprotect_page(dst, PAGE_ENTRY_I);
86 	report(!memcmp(cmp, dst, PAGE_SIZE), "Destination intact");
87 	report_prefix_pop();
88 
89 	report_prefix_pop();
90 }
91 
92 static void test_mvpg(void)
93 {
94 	int binary_size = ((uintptr_t)_binary_s390x_snippets_c_mvpg_snippet_gbin_end -
95 			   (uintptr_t)_binary_s390x_snippets_c_mvpg_snippet_gbin_start);
96 
97 	memcpy(guest, _binary_s390x_snippets_c_mvpg_snippet_gbin_start, binary_size);
98 	memset(src, 0x42, PAGE_SIZE);
99 	memset(dst, 0x43, PAGE_SIZE);
100 	sie(&vm);
101 	report(!memcmp(src, dst, PAGE_SIZE) && *dst == 0x42, "Page moved");
102 }
103 
104 static void setup_guest(void)
105 {
106 	setup_vm();
107 
108 	/* Allocate 1MB as guest memory */
109 	guest = alloc_pages(8);
110 	/* The first two pages are the lowcore */
111 	guest_instr = guest + PAGE_SIZE * 2;
112 
113 	vm.sblk = alloc_page();
114 
115 	vm.sblk->cpuflags = CPUSTAT_ZARCH | CPUSTAT_RUNNING;
116 	vm.sblk->prefix = 0;
117 	/*
118 	 * Pageable guest with the same ASCE as the test programm, but
119 	 * the guest memory 0x0 is offset to start at the allocated
120 	 * guest pages and end after 1MB.
121 	 *
122 	 * It's not pretty but faster and easier than managing guest ASCEs.
123 	 */
124 	vm.sblk->mso = (u64)guest;
125 	vm.sblk->msl = (u64)guest;
126 	vm.sblk->ihcpu = 0xffff;
127 
128 	vm.sblk->crycbd = (uint64_t)alloc_page();
129 
130 	vm.sblk->gpsw.addr = PAGE_SIZE * 4;
131 	vm.sblk->gpsw.mask = 0x0000000180000000ULL;
132 	vm.sblk->ictl = ICTL_OPEREXC | ICTL_PINT;
133 	/* Enable MVPG interpretation as we want to test KVM and not ourselves */
134 	vm.sblk->eca = ECA_MVPGI;
135 
136 	src = guest + PAGE_SIZE * 6;
137 	dst = guest + PAGE_SIZE * 5;
138 	cmp = alloc_page();
139 	memset(cmp, 0, PAGE_SIZE);
140 }
141 
142 int main(void)
143 {
144 	report_prefix_push("mvpg-sie");
145 	if (!sclp_facilities.has_sief2) {
146 		report_skip("SIEF2 facility unavailable");
147 		goto done;
148 	}
149 
150 	setup_guest();
151 	test_mvpg();
152 	test_mvpg_pei();
153 
154 done:
155 	report_prefix_pop();
156 	return report_summary();
157 
158 }
159