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 
compat_by_pvr(uint32_t pvr)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 
pcc_compat(PowerPCCPUClass * pcc,uint32_t compat_pvr,uint32_t min_compat_pvr,uint32_t max_compat_pvr)108 static bool pcc_compat(PowerPCCPUClass *pcc, uint32_t compat_pvr,
109                        uint32_t min_compat_pvr, uint32_t max_compat_pvr)
110 {
111     const CompatInfo *compat = compat_by_pvr(compat_pvr);
112     const CompatInfo *min = compat_by_pvr(min_compat_pvr);
113     const CompatInfo *max = compat_by_pvr(max_compat_pvr);
114 
115     g_assert(!min_compat_pvr || min);
116     g_assert(!max_compat_pvr || max);
117 
118     if (!compat) {
119         /* Not a recognized logical PVR */
120         return false;
121     }
122     if ((min && (compat < min)) || (max && (compat > max))) {
123         /* Outside specified range */
124         return false;
125     }
126     if (!(pcc->pcr_supported & compat->pcr_level)) {
127         /* Not supported by this CPU */
128         return false;
129     }
130     return true;
131 }
132 
ppc_check_compat(PowerPCCPU * cpu,uint32_t compat_pvr,uint32_t min_compat_pvr,uint32_t max_compat_pvr)133 bool ppc_check_compat(PowerPCCPU *cpu, uint32_t compat_pvr,
134                       uint32_t min_compat_pvr, uint32_t max_compat_pvr)
135 {
136     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
137 
138 #if !defined(CONFIG_USER_ONLY)
139     g_assert(cpu->vhyp);
140 #endif
141 
142     return pcc_compat(pcc, compat_pvr, min_compat_pvr, max_compat_pvr);
143 }
144 
ppc_type_check_compat(const char * cputype,uint32_t compat_pvr,uint32_t min_compat_pvr,uint32_t max_compat_pvr)145 bool ppc_type_check_compat(const char *cputype, uint32_t compat_pvr,
146                            uint32_t min_compat_pvr, uint32_t max_compat_pvr)
147 {
148     PowerPCCPUClass *pcc = POWERPC_CPU_CLASS(object_class_by_name(cputype));
149     return pcc_compat(pcc, compat_pvr, min_compat_pvr, max_compat_pvr);
150 }
151 
ppc_set_compat(PowerPCCPU * cpu,uint32_t compat_pvr,Error ** errp)152 void ppc_set_compat(PowerPCCPU *cpu, uint32_t compat_pvr, Error **errp)
153 {
154     const CompatInfo *compat = compat_by_pvr(compat_pvr);
155     CPUPPCState *env = &cpu->env;
156     PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
157     uint64_t pcr;
158 
159     if (!compat_pvr) {
160         pcr = 0;
161     } else if (!compat) {
162         error_setg(errp, "Unknown compatibility PVR 0x%08"PRIx32, compat_pvr);
163         return;
164     } else if (!ppc_check_compat(cpu, compat_pvr, 0, 0)) {
165         error_setg(errp, "Compatibility PVR 0x%08"PRIx32" not valid for CPU",
166                    compat_pvr);
167         return;
168     } else {
169         pcr = compat->pcr;
170     }
171 
172     cpu_synchronize_state(CPU(cpu));
173 
174     if (kvm_enabled() && cpu->compat_pvr != compat_pvr) {
175         int ret = kvmppc_set_compat(cpu, compat_pvr);
176         if (ret < 0) {
177             error_setg_errno(errp, -ret,
178                              "Unable to set CPU compatibility mode in KVM");
179             return;
180         }
181     }
182 
183     cpu->compat_pvr = compat_pvr;
184     env->spr[SPR_PCR] = pcr & pcc->pcr_mask;
185 }
186 
187 typedef struct {
188     uint32_t compat_pvr;
189     Error *err;
190 } SetCompatState;
191 
do_set_compat(CPUState * cs,run_on_cpu_data arg)192 static void do_set_compat(CPUState *cs, run_on_cpu_data arg)
193 {
194     PowerPCCPU *cpu = POWERPC_CPU(cs);
195     SetCompatState *s = arg.host_ptr;
196 
197     ppc_set_compat(cpu, s->compat_pvr, &s->err);
198 }
199 
ppc_set_compat_all(uint32_t compat_pvr,Error ** errp)200 void ppc_set_compat_all(uint32_t compat_pvr, Error **errp)
201 {
202     CPUState *cs;
203 
204     CPU_FOREACH(cs) {
205         SetCompatState s = {
206             .compat_pvr = compat_pvr,
207             .err = NULL,
208         };
209 
210         run_on_cpu(cs, do_set_compat, RUN_ON_CPU_HOST_PTR(&s));
211 
212         if (s.err) {
213             error_propagate(errp, s.err);
214             return;
215         }
216     }
217 }
218 
ppc_compat_max_vthreads(PowerPCCPU * cpu)219 int ppc_compat_max_vthreads(PowerPCCPU *cpu)
220 {
221     const CompatInfo *compat = compat_by_pvr(cpu->compat_pvr);
222     int n_threads = CPU(cpu)->nr_threads;
223 
224     if (cpu->compat_pvr) {
225         g_assert(compat);
226         n_threads = MIN(n_threads, compat->max_vthreads);
227     }
228 
229     return n_threads;
230 }
231 
ppc_compat_prop_get(Object * obj,Visitor * v,const char * name,void * opaque,Error ** errp)232 static void ppc_compat_prop_get(Object *obj, Visitor *v, const char *name,
233                                 void *opaque, Error **errp)
234 {
235     uint32_t compat_pvr = *((uint32_t *)opaque);
236     const char *value;
237 
238     if (!compat_pvr) {
239         value = "";
240     } else {
241         const CompatInfo *compat = compat_by_pvr(compat_pvr);
242 
243         g_assert(compat);
244 
245         value = compat->name;
246     }
247 
248     visit_type_str(v, name, (char **)&value, errp);
249 }
250 
ppc_compat_prop_set(Object * obj,Visitor * v,const char * name,void * opaque,Error ** errp)251 static void ppc_compat_prop_set(Object *obj, Visitor *v, const char *name,
252                                 void *opaque, Error **errp)
253 {
254     Error *local_err = NULL;
255     char *value;
256     uint32_t compat_pvr;
257 
258     visit_type_str(v, name, &value, &local_err);
259     if (local_err) {
260         error_propagate(errp, local_err);
261         return;
262     }
263 
264     if (strcmp(value, "") == 0) {
265         compat_pvr = 0;
266     } else {
267         int i;
268         const CompatInfo *compat = NULL;
269 
270         for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
271             if (strcmp(value, compat_table[i].name) == 0) {
272                 compat = &compat_table[i];
273                 break;
274 
275             }
276         }
277 
278         if (!compat) {
279             error_setg(errp, "Invalid compatibility mode \"%s\"", value);
280             goto out;
281         }
282         compat_pvr = compat->pvr;
283     }
284 
285     *((uint32_t *)opaque) = compat_pvr;
286 
287 out:
288     g_free(value);
289 }
290 
ppc_compat_add_property(Object * obj,const char * name,uint32_t * compat_pvr,const char * basedesc,Error ** errp)291 void ppc_compat_add_property(Object *obj, const char *name,
292                              uint32_t *compat_pvr, const char *basedesc,
293                              Error **errp)
294 {
295     Error *local_err = NULL;
296     gchar *namesv[ARRAY_SIZE(compat_table) + 1];
297     gchar *names, *desc;
298     int i;
299 
300     object_property_add(obj, name, "string",
301                         ppc_compat_prop_get, ppc_compat_prop_set, NULL,
302                         compat_pvr, &local_err);
303     if (local_err) {
304         goto out;
305     }
306 
307     for (i = 0; i < ARRAY_SIZE(compat_table); i++) {
308         /*
309          * Have to discard const here, because g_strjoinv() takes
310          * (gchar **), not (const gchar **) :(
311          */
312         namesv[i] = (gchar *)compat_table[i].name;
313     }
314     namesv[ARRAY_SIZE(compat_table)] = NULL;
315 
316     names = g_strjoinv(", ", namesv);
317     desc = g_strdup_printf("%s. Valid values are %s.", basedesc, names);
318     object_property_set_description(obj, name, desc, &local_err);
319 
320     g_free(names);
321     g_free(desc);
322 
323 out:
324     error_propagate(errp, local_err);
325 }
326