xref: /openbmc/qemu/target/ppc/compat.c (revision a89f364a) 
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_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 |
55                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_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
63         .pcr_level = PCR_COMPAT_2_06,
64         .max_vthreads = 4,
65     },
66     {
67         .name = "power7+",
68         .pvr = CPU_POWERPC_LOGICAL_2_06_PLUS,
69         .pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07 | PCR_COMPAT_2_06 | PCR_TM_DIS,
70         .pcr_level = PCR_COMPAT_2_06,
71         .max_vthreads = 4,
72     },
73     { /* POWER8, ISA2.07 */
74         .name = "power8",
75         .pvr = CPU_POWERPC_LOGICAL_2_07,
76         .pcr = PCR_COMPAT_3_00 | PCR_COMPAT_2_07,
77         .pcr_level = PCR_COMPAT_2_07,
78         .max_vthreads = 8,
79     },
80     { /* POWER9, ISA3.00 */
81         .name = "power9",
82         .pvr = CPU_POWERPC_LOGICAL_3_00,
83         .pcr = PCR_COMPAT_3_00,
84         .pcr_level = PCR_COMPAT_3_00,
85         /*
86          * POWER9 hardware only supports 4 threads / core, but this
87          * limit is for guests.  We need to support 8 vthreads/vcore
88          * on POWER9 for POWER8 compatibility guests, and it's very
89          * confusing if half of the threads disappear from the guest
90          * if it announces it's POWER9 aware at CAS time.
91          */
92         .max_vthreads = 8,
93     },
94 };
95 
96 static const CompatInfo *compat_by_pvr(uint32_t pvr)
97 {
98     int i;
99 
100     for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
101         if (compat_table[i].pvr == pvr) {
102             return &compat_table[i];
103         }
104     }
105     return NULL;
106 }
107 
108 bool ppc_check_compat(PowerPCCPU *cpu, uint32_t compat_pvr,
109                       uint32_t min_compat_pvr, uint32_t max_compat_pvr)
110 {
111     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
112     const CompatInfo *compat = compat_by_pvr(compat_pvr);
113     const CompatInfo *min = compat_by_pvr(min_compat_pvr);
114     const CompatInfo *max = compat_by_pvr(max_compat_pvr);
115 
116 #if !defined(CONFIG_USER_ONLY)
117     g_assert(cpu->vhyp);
118 #endif
119     g_assert(!min_compat_pvr || min);
120     g_assert(!max_compat_pvr || max);
121 
122     if (!compat) {
123         /* Not a recognized logical PVR */
124         return false;
125     }
126     if ((min && (compat < min)) || (max && (compat > max))) {
127         /* Outside specified range */
128         return false;
129     }
130     if (!(pcc->pcr_supported & compat->pcr_level)) {
131         /* Not supported by this CPU */
132         return false;
133     }
134     return true;
135 }
136 
137 void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp)
138 {
139     const CompatInfo *compat = compat_by_pvr(compat_pvr);
140     CPUPPCState *env = &cpu->env;
141     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
142     uint64_t pcr;
143 
144     if (!compat_pvr) {
145         pcr = 0;
146     } else if (!compat) {
147         error_setg(errp, "Unknown compatibility PVR 0x%08"PRIx32, compat_pvr);
148         return;
149     } else if (!ppc_check_compat(cpu, compat_pvr, 0, 0)) {
150         error_setg(errp, "Compatibility PVR 0x%08"PRIx32" not valid for CPU",
151                    compat_pvr);
152         return;
153     } else {
154         pcr = compat->pcr;
155     }
156 
157     cpu_synchronize_state(CPU(cpu));
158 
159     if (kvm_enabled() && cpu->compat_pvr != compat_pvr) {
160         int ret = kvmppc_set_compat(cpu, compat_pvr);
161         if (ret < 0) {
162             error_setg_errno(errp, -ret,
163                              "Unable to set CPU compatibility mode in KVM");
164             return;
165         }
166     }
167 
168     cpu->compat_pvr = compat_pvr;
169     env->spr[SPR_PCR] = pcr & pcc->pcr_mask;
170 }
171 
172 typedef struct {
173     uint32_t compat_pvr;
174     Error *err;
175 } SetCompatState;
176 
177 static void do_set_compat(CPUState *cs, run_on_cpu_data arg)
178 {
179     PowerPCCPU *cpu = POWERPC_CPU(cs);
180     SetCompatState *s = arg.host_ptr;
181 
182     ppc_set_compat(cpu, s->compat_pvr, &s->err);
183 }
184 
185 void ppc_set_compat_all(uint32_t compat_pvr, Error **errp)
186 {
187     CPUState *cs;
188 
189     CPU_FOREACH(cs) {
190         SetCompatState s = {
191             .compat_pvr = compat_pvr,
192             .err = NULL,
193         };
194 
195         run_on_cpu(cs, do_set_compat, RUN_ON_CPU_HOST_PTR(&s));
196 
197         if (s.err) {
198             error_propagate(errp, s.err);
199             return;
200         }
201     }
202 }
203 
204 int ppc_compat_max_vthreads(PowerPCCPU *cpu)
205 {
206     const CompatInfo *compat = compat_by_pvr(cpu->compat_pvr);
207     int n_threads = CPU(cpu)->nr_threads;
208 
209     if (cpu->compat_pvr) {
210         g_assert(compat);
211         n_threads = MIN(n_threads, compat->max_vthreads);
212     }
213 
214     return n_threads;
215 }
216 
217 static void ppc_compat_prop_get(Object *obj, Visitor *v, const char *name,
218                                 void *opaque, Error **errp)
219 {
220     uint32_t compat_pvr = *((uint32_t *)opaque);
221     const char *value;
222 
223     if (!compat_pvr) {
224         value = "";
225     } else {
226         const CompatInfo *compat = compat_by_pvr(compat_pvr);
227 
228         g_assert(compat);
229 
230         value = compat->name;
231     }
232 
233     visit_type_str(v, name, (char **)&value, errp);
234 }
235 
236 static void ppc_compat_prop_set(Object *obj, Visitor *v, const char *name,
237                                 void *opaque, Error **errp)
238 {
239     Error *local_err = NULL;
240     char *value;
241     uint32_t compat_pvr;
242 
243     visit_type_str(v, name, &value, &local_err);
244     if (local_err) {
245         error_propagate(errp, local_err);
246         return;
247     }
248 
249     if (strcmp(value, "") == 0) {
250         compat_pvr = 0;
251     } else {
252         int i;
253         const CompatInfo *compat = NULL;
254 
255         for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
256             if (strcmp(value, compat_table[i].name) == 0) {
257                 compat = &compat_table[i];
258                 break;
259 
260             }
261         }
262 
263         if (!compat) {
264             error_setg(errp, "Invalid compatibility mode \"%s\"", value);
265             goto out;
266         }
267         compat_pvr = compat->pvr;
268     }
269 
270     *((uint32_t *)opaque) = compat_pvr;
271 
272 out:
273     g_free(value);
274 }
275 
276 void ppc_compat_add_property(Object *obj, const char *name,
277                              uint32_t *compat_pvr, const char *basedesc,
278                              Error **errp)
279 {
280     Error *local_err = NULL;
281     gchar *namesv[ARRAY_SIZE(compat_table) + 1];
282     gchar *names, *desc;
283     int i;
284 
285     object_property_add(obj, name, "string",
286                         ppc_compat_prop_get, ppc_compat_prop_set, NULL,
287                         compat_pvr, &local_err);
288     if (local_err) {
289         goto out;
290     }
291 
292     for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
293         /*
294          * Have to discard const here, because g_strjoinv() takes
295          * (gchar **), not (const gchar **) :(
296          */
297         namesv[i] = (gchar *)compat_table[i].name;
298     }
299     namesv[ARRAY_SIZE(compat_table)] = NULL;
300 
301     names = g_strjoinv(", ", namesv);
302     desc = g_strdup_printf("%s. Valid values are %s.", basedesc, names);
303     object_property_set_description(obj, name, desc, &local_err);
304 
305     g_free(names);
306     g_free(desc);
307 
308 out:
309     error_propagate(errp, local_err);
310 }
311