xref: /openbmc/qemu/target/ppc/compat.c (revision 2df9f571)
1 /*
2  *  PowerPC CPU initialization for qemu.
3  *
4  *  Copyright 2016, David Gibson, Red Hat Inc. <dgibson@redhat.com>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "sysemu/hw_accel.h"
22 #include "sysemu/kvm.h"
23 #include "kvm_ppc.h"
24 #include "sysemu/cpus.h"
25 #include "qemu/error-report.h"
26 #include "qapi/error.h"
27 #include "qapi/visitor.h"
28 #include "cpu-models.h"
29 
30 typedef struct {
31     const char *name;
32     uint32_t pvr;
33     uint64_t pcr;
34     uint64_t pcr_level;
35 
36     /*
37      * Maximum allowed virtual threads per virtual core
38      *
39      * This is to stop older guests getting confused by seeing more
40      * threads than they think the cpu can support.  Usually it's
41      * equal to the number of threads supported on bare metal
42      * hardware, but not always (see POWER9).
43      */
44     int max_vthreads;
45 } CompatInfo;
46 
47 static const CompatInfo compat_table[] = {
48     /*
49      * Ordered from oldest to newest - the code relies on this
50      */
51     { /* POWER6, ISA2.05 */
52         .name = "power6",
53         .pvr = CPU_POWERPC_LOGICAL_2_05,
54         .pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00 | PCR_COMPAT_2_07 |
55                PCR_COMPAT_2_06 | PCR_COMPAT_2_05 | PCR_TM_DIS | PCR_VSX_DIS,
56         .pcr_level = PCR_COMPAT_2_05,
57         .max_vthreads = 2,
58     },
59     { /* POWER7, ISA2.06 */
60         .name = "power7",
61         .pvr = CPU_POWERPC_LOGICAL_2_06,
62         .pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00 | PCR_COMPAT_2_07 |
63                PCR_COMPAT_2_06 | PCR_TM_DIS,
64         .pcr_level = PCR_COMPAT_2_06,
65         .max_vthreads = 4,
66     },
67     {
68         .name = "power7+",
69         .pvr = CPU_POWERPC_LOGICAL_2_06_PLUS,
70         .pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00 | PCR_COMPAT_2_07 |
71                PCR_COMPAT_2_06 | PCR_TM_DIS,
72         .pcr_level = PCR_COMPAT_2_06,
73         .max_vthreads = 4,
74     },
75     { /* POWER8, ISA2.07 */
76         .name = "power8",
77         .pvr = CPU_POWERPC_LOGICAL_2_07,
78         .pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00 | PCR_COMPAT_2_07,
79         .pcr_level = PCR_COMPAT_2_07,
80         .max_vthreads = 8,
81     },
82     { /* POWER9, ISA3.00 */
83         .name = "power9",
84         .pvr = CPU_POWERPC_LOGICAL_3_00,
85         .pcr = PCR_COMPAT_3_10 | PCR_COMPAT_3_00,
86         .pcr_level = PCR_COMPAT_3_00,
87         /*
88          * POWER9 hardware only supports 4 threads / core, but this
89          * limit is for guests.  We need to support 8 vthreads/vcore
90          * on POWER9 for POWER8 compatibility guests, and it's very
91          * confusing if half of the threads disappear from the guest
92          * if it announces it's POWER9 aware at CAS time.
93          */
94         .max_vthreads = 8,
95     },
96     { /* POWER10, ISA3.10 */
97         .name = "power10",
98         .pvr = CPU_POWERPC_LOGICAL_3_10,
99         .pcr = PCR_COMPAT_3_10,
100         .pcr_level = PCR_COMPAT_3_10,
101         .max_vthreads = 8,
102     },
103 };
104 
105 static const CompatInfo *compat_by_pvr(uint32_t pvr)
106 {
107     int i;
108 
109     for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
110         if (compat_table[i].pvr == pvr) {
111             return &compat_table[i];
112         }
113     }
114     return NULL;
115 }
116 
117 static bool pcc_compat(PowerPCCPUClass *pcc, uint32_t compat_pvr,
118                        uint32_t min_compat_pvr, uint32_t max_compat_pvr)
119 {
120     const CompatInfo *compat = compat_by_pvr(compat_pvr);
121     const CompatInfo *min = compat_by_pvr(min_compat_pvr);
122     const CompatInfo *max = compat_by_pvr(max_compat_pvr);
123 
124     g_assert(!min_compat_pvr || min);
125     g_assert(!max_compat_pvr || max);
126 
127     if (!compat) {
128         /* Not a recognized logical PVR */
129         return false;
130     }
131     if ((min && (compat < min)) || (max && (compat > max))) {
132         /* Outside specified range */
133         return false;
134     }
135     if (!(pcc->pcr_supported & compat->pcr_level)) {
136         /* Not supported by this CPU */
137         return false;
138     }
139     return true;
140 }
141 
142 bool ppc_check_compat(PowerPCCPU *cpu, uint32_t compat_pvr,
143                       uint32_t min_compat_pvr, uint32_t max_compat_pvr)
144 {
145     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
146 
147 #if !defined(CONFIG_USER_ONLY)
148     g_assert(cpu->vhyp);
149 #endif
150 
151     return pcc_compat(pcc, compat_pvr, min_compat_pvr, max_compat_pvr);
152 }
153 
154 bool ppc_type_check_compat(const char *cputype, uint32_t compat_pvr,
155                            uint32_t min_compat_pvr, uint32_t max_compat_pvr)
156 {
157     PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(object_class_by_name(cputype));
158     return pcc_compat(pcc, compat_pvr, min_compat_pvr, max_compat_pvr);
159 }
160 
161 void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp)
162 {
163     const CompatInfo *compat = compat_by_pvr(compat_pvr);
164     CPUPPCState *env = &cpu->env;
165     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
166     uint64_t pcr;
167 
168     if (!compat_pvr) {
169         pcr = 0;
170     } else if (!compat) {
171         error_setg(errp, "Unknown compatibility PVR 0x%08"PRIx32, compat_pvr);
172         return;
173     } else if (!ppc_check_compat(cpu, compat_pvr, 0, 0)) {
174         error_setg(errp, "Compatibility PVR 0x%08"PRIx32" not valid for CPU",
175                    compat_pvr);
176         return;
177     } else {
178         pcr = compat->pcr;
179     }
180 
181     cpu_synchronize_state(CPU(cpu));
182 
183     if (kvm_enabled() && cpu->compat_pvr != compat_pvr) {
184         int ret = kvmppc_set_compat(cpu, compat_pvr);
185         if (ret < 0) {
186             error_setg_errno(errp, -ret,
187                              "Unable to set CPU compatibility mode in KVM");
188             return;
189         }
190     }
191 
192     cpu->compat_pvr = compat_pvr;
193     env->spr[SPR_PCR] = pcr & pcc->pcr_mask;
194 }
195 
196 typedef struct {
197     uint32_t compat_pvr;
198     Error *err;
199 } SetCompatState;
200 
201 static void do_set_compat(CPUState *cs, run_on_cpu_data arg)
202 {
203     PowerPCCPU *cpu = POWERPC_CPU(cs);
204     SetCompatState *s = arg.host_ptr;
205 
206     ppc_set_compat(cpu, s->compat_pvr, &s->err);
207 }
208 
209 void ppc_set_compat_all(uint32_t compat_pvr, Error **errp)
210 {
211     CPUState *cs;
212 
213     CPU_FOREACH(cs) {
214         SetCompatState s = {
215             .compat_pvr = compat_pvr,
216             .err = NULL,
217         };
218 
219         run_on_cpu(cs, do_set_compat, RUN_ON_CPU_HOST_PTR(&s));
220 
221         if (s.err) {
222             error_propagate(errp, s.err);
223             return;
224         }
225     }
226 }
227 
228 int ppc_compat_max_vthreads(PowerPCCPU *cpu)
229 {
230     const CompatInfo *compat = compat_by_pvr(cpu->compat_pvr);
231     int n_threads = CPU(cpu)->nr_threads;
232 
233     if (cpu->compat_pvr) {
234         g_assert(compat);
235         n_threads = MIN(n_threads, compat->max_vthreads);
236     }
237 
238     return n_threads;
239 }
240 
241 static void ppc_compat_prop_get(Object *obj, Visitor *v, const char *name,
242                                 void *opaque, Error **errp)
243 {
244     uint32_t compat_pvr = *((uint32_t *)opaque);
245     const char *value;
246 
247     if (!compat_pvr) {
248         value = "";
249     } else {
250         const CompatInfo *compat = compat_by_pvr(compat_pvr);
251 
252         g_assert(compat);
253 
254         value = compat->name;
255     }
256 
257     visit_type_str(v, name, (char **)&value, errp);
258 }
259 
260 static void ppc_compat_prop_set(Object *obj, Visitor *v, const char *name,
261                                 void *opaque, Error **errp)
262 {
263     Error *local_err = NULL;
264     char *value;
265     uint32_t compat_pvr;
266 
267     visit_type_str(v, name, &value, &local_err);
268     if (local_err) {
269         error_propagate(errp, local_err);
270         return;
271     }
272 
273     if (strcmp(value, "") == 0) {
274         compat_pvr = 0;
275     } else {
276         int i;
277         const CompatInfo *compat = NULL;
278 
279         for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
280             if (strcmp(value, compat_table[i].name) == 0) {
281                 compat = &compat_table[i];
282                 break;
283 
284             }
285         }
286 
287         if (!compat) {
288             error_setg(errp, "Invalid compatibility mode \"%s\"", value);
289             goto out;
290         }
291         compat_pvr = compat->pvr;
292     }
293 
294     *((uint32_t *)opaque) = compat_pvr;
295 
296 out:
297     g_free(value);
298 }
299 
300 void ppc_compat_add_property(Object *obj, const char *name,
301                              uint32_t *compat_pvr, const char *basedesc)
302 {
303     gchar *namesv[ARRAY_SIZE(compat_table) + 1];
304     gchar *names, *desc;
305     int i;
306 
307     object_property_add(obj, name, "string",
308                         ppc_compat_prop_get, ppc_compat_prop_set, NULL,
309                         compat_pvr);
310 
311     for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
312         /*
313          * Have to discard const here, because g_strjoinv() takes
314          * (gchar **), not (const gchar **) :(
315          */
316         namesv[i] = (gchar *)compat_table[i].name;
317     }
318     namesv[ARRAY_SIZE(compat_table)] = NULL;
319 
320     names = g_strjoinv(", ", namesv);
321     desc = g_strdup_printf("%s. Valid values are %s.", basedesc, names);
322     object_property_set_description(obj, name, desc);
323 
324     g_free(names);
325     g_free(desc);
326 }
327