xref: /kvm-unit-tests/powerpc/sprs.c (revision ffd9da55fdb2593e5353e9b6c5606e62b120289a)
1 /*
2  * Test Special Purpose Registers
3  *
4  * Copyright 2017  Thomas Huth, Red Hat Inc.
5  *
6  * This work is licensed under the terms of the GNU LGPL, version 2.
7  *
8  * The basic idea of this test is to check whether the contents of the Special
9  * Purpose Registers (SPRs) are preserved correctly during migration. So we
10  * fill in the SPRs with a well-known value, read the values back (since not
11  * all bits might be retained in the SPRs), then wait for migration to complete
12  * (if the '-w' option has been specified) so that the user has a chance to
13  * migrate the VM. Alternatively, the test can also simply sleep a little bit
14  * with the H_CEDE hypercall, in the hope that we'll get scheduled to another
15  * host CPU and thus register contents might have changed, too (in case of
16  * bugs). Finally, we read back the values from the SPRs and compare them with
17  * the values before the migration. Mismatches are reported as test failures.
18  * Note that we do not test all SPRs since some of the registers change their
19  * content automatically, and some are only accessible with hypervisor privi-
20  * leges or have bad side effects, so we have to omit those registers.
21  */
22 #include <libcflat.h>
23 #include <util.h>
24 #include <alloc.h>
25 #include <asm/handlers.h>
26 #include <asm/hcall.h>
27 #include <asm/processor.h>
28 #include <asm/barrier.h>
29 
30 #define mfspr(nr) ({ \
31 	uint64_t ret; \
32 	asm volatile("mfspr %0,%1" : "=r"(ret) : "i"(nr)); \
33 	ret; \
34 })
35 
36 #define mtspr(nr, val) \
37 	asm volatile("mtspr %0,%1" : : "i"(nr), "r"(val))
38 
39 uint64_t before[1024], after[1024];
40 
41 static int h_get_term_char(uint64_t termno)
42 {
43 	register uint64_t r3 asm("r3") = 0x54; /* H_GET_TERM_CHAR */
44 	register uint64_t r4 asm("r4") = termno;
45 	register uint64_t r5 asm("r5");
46 
47 	asm volatile (" sc 1 "	: "+r"(r3), "+r"(r4), "=r"(r5)
48 				: "r"(r3),  "r"(r4));
49 
50 	return r3 == H_SUCCESS && r4 > 0 ? r5 >> 48 : 0;
51 }
52 
53 /* Common SPRs for all PowerPC CPUs */
54 static void set_sprs_common(uint64_t val)
55 {
56 	mtspr(9, val);		/* CTR */
57 	// mtspr(273, val);	/* SPRG1 */  /* Used by our exception handler */
58 	mtspr(274, val);	/* SPRG2 */
59 	mtspr(275, val);	/* SPRG3 */
60 }
61 
62 /* SPRs from PowerPC Operating Environment Architecture, Book III, Vers. 2.01 */
63 static void set_sprs_book3s_201(uint64_t val)
64 {
65 	mtspr(18, val);		/* DSISR */
66 	mtspr(19, val);		/* DAR */
67 	mtspr(152, val);	/* CTRL */
68 	mtspr(256, val);	/* VRSAVE */
69 	mtspr(786, val);	/* MMCRA */
70 	mtspr(795, val);	/* MMCR0 */
71 	mtspr(798, val);	/* MMCR1 */
72 }
73 
74 /* SPRs from PowerISA 2.07 Book III-S */
75 static void set_sprs_book3s_207(uint64_t val)
76 {
77 	mtspr(3, val);		/* DSCR */
78 	mtspr(13, val);		/* AMR */
79 	mtspr(17, val);		/* DSCR */
80 	mtspr(18, val);		/* DSISR */
81 	mtspr(19, val);		/* DAR */
82 	mtspr(29, val);		/* AMR */
83 	mtspr(61, val);		/* IAMR */
84 	// mtspr(152, val);	/* CTRL */  /* TODO: Needs a fix in KVM */
85 	mtspr(153, val);	/* FSCR */
86 	mtspr(157, val);	/* UAMOR */
87 	mtspr(159, val);	/* PSPB */
88 	mtspr(256, val);	/* VRSAVE */
89 	// mtspr(272, val);	/* SPRG0 */ /* Used by our exception handler */
90 	mtspr(769, val);	/* MMCR2 */
91 	mtspr(770, val);	/* MMCRA */
92 	mtspr(771, val);	/* PMC1 */
93 	mtspr(772, val);	/* PMC2 */
94 	mtspr(773, val);	/* PMC3 */
95 	mtspr(774, val);	/* PMC4 */
96 	mtspr(775, val);	/* PMC5 */
97 	mtspr(776, val);	/* PMC6 */
98 	mtspr(779, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070);	/* MMCR0 */
99 	mtspr(784, val);	/* SIER */
100 	mtspr(785, val);	/* MMCR2 */
101 	mtspr(786, val);	/* MMCRA */
102 	mtspr(787, val);	/* PMC1 */
103 	mtspr(788, val);	/* PMC2 */
104 	mtspr(789, val);	/* PMC3 */
105 	mtspr(790, val);	/* PMC4 */
106 	mtspr(791, val);	/* PMC5 */
107 	mtspr(792, val);	/* PMC6 */
108 	mtspr(795, (val & 0xfffffffffbab3fffULL) | 0xfa0b2070);	/* MMCR0 */
109 	mtspr(796, val);	/* SIAR */
110 	mtspr(797, val);	/* SDAR */
111 	mtspr(798, val);	/* MMCR1 */
112 	mtspr(800, val);	/* BESCRS */
113 	mtspr(801, val);	/* BESCCRSU */
114 	mtspr(802, val);	/* BESCRR */
115 	mtspr(803, val);	/* BESCRRU */
116 	mtspr(804, val);	/* EBBHR */
117 	mtspr(805, val);	/* EBBRR */
118 	mtspr(806, val);	/* BESCR */
119 	mtspr(815, val);	/* TAR */
120 }
121 
122 /* SPRs from PowerISA 3.00 Book III */
123 static void set_sprs_book3s_300(uint64_t val)
124 {
125 	set_sprs_book3s_207(val);
126 	mtspr(48, val);		/* PIDR */
127 	mtspr(144, val);	/* TIDR */
128 	mtspr(823, val);	/* PSSCR */
129 }
130 
131 static void set_sprs(uint64_t val)
132 {
133 	uint32_t pvr = mfspr(287);	/* Processor Version Register */
134 
135 	set_sprs_common(val);
136 
137 	switch (pvr >> 16) {
138 	case 0x39:			/* PPC970 */
139 	case 0x3C:			/* PPC970FX */
140 	case 0x44:			/* PPC970MP */
141 		set_sprs_book3s_201(val);
142 		break;
143 	case 0x4b:			/* POWER8E */
144 	case 0x4c:			/* POWER8NVL */
145 	case 0x4d:			/* POWER8 */
146 		set_sprs_book3s_207(val);
147 		break;
148 	case 0x4e:			/* POWER9 */
149 		set_sprs_book3s_300(val);
150 		break;
151 	default:
152 		puts("Warning: Unknown processor version!\n");
153 	}
154 }
155 
156 static void get_sprs_common(uint64_t *v)
157 {
158 	v[9] = mfspr(9);	/* CTR */
159 	// v[273] = mfspr(273);	/* SPRG1 */ /* Used by our exception handler */
160 	v[274] = mfspr(274);	/* SPRG2 */
161 	v[275] = mfspr(275);	/* SPRG3 */
162 }
163 
164 static void get_sprs_book3s_201(uint64_t *v)
165 {
166 	v[18] = mfspr(18);	/* DSISR */
167 	v[19] = mfspr(19);	/* DAR */
168 	v[136] = mfspr(136);	/* CTRL */
169 	v[256] = mfspr(256);	/* VRSAVE */
170 	v[786] = mfspr(786);	/* MMCRA */
171 	v[795] = mfspr(795);	/* MMCR0 */
172 	v[798] = mfspr(798);	/* MMCR1 */
173 }
174 
175 static void get_sprs_book3s_207(uint64_t *v)
176 {
177 	v[3] = mfspr(3);	/* DSCR */
178 	v[13] = mfspr(13);	/* AMR */
179 	v[17] = mfspr(17);	/* DSCR */
180 	v[18] = mfspr(18);	/* DSISR */
181 	v[19] = mfspr(19);	/* DAR */
182 	v[29] = mfspr(29);	/* AMR */
183 	v[61] = mfspr(61);	/* IAMR */
184 	// v[136] = mfspr(136);	/* CTRL */  /* TODO: Needs a fix in KVM */
185 	v[153] = mfspr(153);	/* FSCR */
186 	v[157] = mfspr(157);	/* UAMOR */
187 	v[159] = mfspr(159);	/* PSPB */
188 	v[256] = mfspr(256);	/* VRSAVE */
189 	v[259] = mfspr(259);	/* SPRG3 (read only) */
190 	// v[272] = mfspr(272);	/* SPRG0 */  /* Used by our exception handler */
191 	v[769] = mfspr(769);	/* MMCR2 */
192 	v[770] = mfspr(770);	/* MMCRA */
193 	v[771] = mfspr(771);	/* PMC1 */
194 	v[772] = mfspr(772);	/* PMC2 */
195 	v[773] = mfspr(773);	/* PMC3 */
196 	v[774] = mfspr(774);	/* PMC4 */
197 	v[775] = mfspr(775);	/* PMC5 */
198 	v[776] = mfspr(776);	/* PMC6 */
199 	v[779] = mfspr(779);	/* MMCR0 */
200 	v[780] = mfspr(780);	/* SIAR (read only) */
201 	v[781] = mfspr(781);	/* SDAR (read only) */
202 	v[782] = mfspr(782);	/* MMCR1 (read only) */
203 	v[784] = mfspr(784);	/* SIER */
204 	v[785] = mfspr(785);	/* MMCR2 */
205 	v[786] = mfspr(786);	/* MMCRA */
206 	v[787] = mfspr(787);	/* PMC1 */
207 	v[788] = mfspr(788);	/* PMC2 */
208 	v[789] = mfspr(789);	/* PMC3 */
209 	v[790] = mfspr(790);	/* PMC4 */
210 	v[791] = mfspr(791);	/* PMC5 */
211 	v[792] = mfspr(792);	/* PMC6 */
212 	v[795] = mfspr(795);	/* MMCR0 */
213 	v[796] = mfspr(796);	/* SIAR */
214 	v[797] = mfspr(797);	/* SDAR */
215 	v[798] = mfspr(798);	/* MMCR1 */
216 	v[800] = mfspr(800);	/* BESCRS */
217 	v[801] = mfspr(801);	/* BESCCRSU */
218 	v[802] = mfspr(802);	/* BESCRR */
219 	v[803] = mfspr(803);	/* BESCRRU */
220 	v[804] = mfspr(804);	/* EBBHR */
221 	v[805] = mfspr(805);	/* EBBRR */
222 	v[806] = mfspr(806);	/* BESCR */
223 	v[815] = mfspr(815);	/* TAR */
224 }
225 
226 static void get_sprs_book3s_300(uint64_t *v)
227 {
228 	get_sprs_book3s_207(v);
229 	v[48] = mfspr(48);	/* PIDR */
230 	v[144] = mfspr(144);	/* TIDR */
231 	v[823] = mfspr(823);	/* PSSCR */
232 }
233 
234 static void get_sprs(uint64_t *v)
235 {
236 	uint32_t pvr = mfspr(287);	/* Processor Version Register */
237 
238 	get_sprs_common(v);
239 
240 	switch (pvr >> 16) {
241 	case 0x39:			/* PPC970 */
242 	case 0x3C:			/* PPC970FX */
243 	case 0x44:			/* PPC970MP */
244 		get_sprs_book3s_201(v);
245 		break;
246 	case 0x4b:			/* POWER8E */
247 	case 0x4c:			/* POWER8NVL */
248 	case 0x4d:			/* POWER8 */
249 		get_sprs_book3s_207(v);
250 		break;
251 	case 0x4e:			/* POWER9 */
252 		get_sprs_book3s_300(v);
253 		break;
254 	}
255 }
256 
257 int main(int argc, char **argv)
258 {
259 	int i;
260 	bool pause = false;
261 	uint64_t pat = 0xcafefacec0debabeULL;
262 	const uint64_t patterns[] = {
263 		0xcafefacec0debabeULL, ~0xcafefacec0debabeULL,
264 		0xAAAA5555AAAA5555ULL, 0x5555AAAA5555AAAAULL,
265 		0x1234567890ABCDEFULL, 0xFEDCBA0987654321ULL,
266 		-1ULL,
267 	};
268 
269 	for (i = 1; i < argc; i++) {
270 		if (!strcmp(argv[i], "-w")) {
271 			pause = true;
272 		} else if (!strcmp(argv[i], "-p")) {
273 			i += 1;
274 			if (i >= argc || *argv[i] < '0'
275 			    || *argv[i] >= '0' + ARRAY_SIZE(patterns))
276 				report_abort("Error: bad value for -p");
277 			pat ^= patterns[*argv[i] - '0'];
278 		} else if (!strcmp(argv[i], "-t")) {
279 			/* Randomize with timebase register */
280 			asm volatile("mftb %0" : "=r"(i));
281 			pat ^= i;
282 			asm volatile("mftb %0" : "=r"(i));
283 			pat ^= ~(uint64_t)i << 32;
284 		} else {
285 			report_abort("Warning: Unsupported argument: %s",
286 			             argv[i]);
287 		}
288 	}
289 
290 	printf("Settings SPRs to %#lx...\n", pat);
291 	set_sprs(pat);
292 
293 	memset(before, 0, sizeof(before));
294 	memset(after, 0, sizeof(after));
295 
296 	get_sprs(before);
297 
298 	if (pause) {
299 		puts("Now migrate the VM, then press a key to continue...\n");
300 		while (h_get_term_char(0) == 0)
301 			cpu_relax();
302 	} else {
303 		puts("Sleeping...\n");
304 		handle_exception(0x900, &dec_except_handler, NULL);
305 		asm volatile ("mtdec %0" : : "r" (0x3FFFFFFF));
306 		hcall(H_CEDE);
307 	}
308 
309 	get_sprs(after);
310 
311 	puts("Checking SPRs...\n");
312 	for (i = 0; i < 1024; i++) {
313 		if (before[i] != 0 || after[i] != 0)
314 			report("SPR %d:\t%#018lx <==> %#018lx",
315 				before[i] == after[i], i, before[i], after[i]);
316 	}
317 
318 	return report_summary();
319 }
320