xref: /openbmc/qemu/target/s390x/arch_dump.c (revision 93e0932b)
1 /*
2  * writing ELF notes for s390x arch
3  *
4  *
5  * Copyright IBM Corp. 2012, 2013
6  *
7  *     Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  *
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/units.h"
16 #include "cpu.h"
17 #include "s390x-internal.h"
18 #include "elf.h"
19 #include "sysemu/dump.h"
20 #include "hw/s390x/pv.h"
21 #include "kvm/kvm_s390x.h"
22 
23 struct S390xUserRegsStruct {
24     uint64_t psw[2];
25     uint64_t gprs[16];
26     uint32_t acrs[16];
27 } QEMU_PACKED;
28 
29 typedef struct S390xUserRegsStruct S390xUserRegs;
30 
31 struct S390xElfPrstatusStruct {
32     uint8_t pad1[32];
33     uint32_t pid;
34     uint8_t pad2[76];
35     S390xUserRegs regs;
36     uint8_t pad3[16];
37 } QEMU_PACKED;
38 
39 typedef struct S390xElfPrstatusStruct S390xElfPrstatus;
40 
41 struct S390xElfFpregsetStruct {
42     uint32_t fpc;
43     uint32_t pad;
44     uint64_t fprs[16];
45 } QEMU_PACKED;
46 
47 typedef struct S390xElfFpregsetStruct S390xElfFpregset;
48 
49 struct S390xElfVregsLoStruct {
50     uint64_t vregs[16];
51 } QEMU_PACKED;
52 
53 typedef struct S390xElfVregsLoStruct S390xElfVregsLo;
54 
55 struct S390xElfVregsHiStruct {
56     uint64_t vregs[16][2];
57 } QEMU_PACKED;
58 
59 typedef struct S390xElfVregsHiStruct S390xElfVregsHi;
60 
61 struct S390xElfGSCBStruct {
62     uint64_t gsregs[4];
63 } QEMU_PACKED;
64 
65 typedef struct S390xElfGSCBStruct S390xElfGSCB;
66 
67 typedef struct noteStruct {
68     Elf64_Nhdr hdr;
69     char name[8];
70     union {
71         S390xElfPrstatus prstatus;
72         S390xElfFpregset fpregset;
73         S390xElfVregsLo vregslo;
74         S390xElfVregsHi vregshi;
75         S390xElfGSCB gscb;
76         uint32_t prefix;
77         uint64_t timer;
78         uint64_t todcmp;
79         uint32_t todpreg;
80         uint64_t ctrs[16];
81         uint8_t dynamic[1];  /*
82                               * Would be a flexible array member, if
83                               * that was legal inside a union. Real
84                               * size comes from PV info interface.
85                               */
86     } contents;
87 } QEMU_PACKED Note;
88 
89 static bool pv_dump_initialized;
90 
91 static void s390x_write_elf64_prstatus(Note *note, S390CPU *cpu, int id)
92 {
93     int i;
94     S390xUserRegs *regs;
95 
96     note->hdr.n_type = cpu_to_be32(NT_PRSTATUS);
97 
98     regs = &(note->contents.prstatus.regs);
99     regs->psw[0] = cpu_to_be64(cpu->env.psw.mask);
100     regs->psw[1] = cpu_to_be64(cpu->env.psw.addr);
101     for (i = 0; i <= 15; i++) {
102         regs->acrs[i] = cpu_to_be32(cpu->env.aregs[i]);
103         regs->gprs[i] = cpu_to_be64(cpu->env.regs[i]);
104     }
105     note->contents.prstatus.pid = id;
106 }
107 
108 static void s390x_write_elf64_fpregset(Note *note, S390CPU *cpu, int id)
109 {
110     int i;
111     CPUS390XState *cs = &cpu->env;
112 
113     note->hdr.n_type = cpu_to_be32(NT_FPREGSET);
114     note->contents.fpregset.fpc = cpu_to_be32(cpu->env.fpc);
115     for (i = 0; i <= 15; i++) {
116         note->contents.fpregset.fprs[i] = cpu_to_be64(*get_freg(cs, i));
117     }
118 }
119 
120 static void s390x_write_elf64_vregslo(Note *note, S390CPU *cpu,  int id)
121 {
122     int i;
123 
124     note->hdr.n_type = cpu_to_be32(NT_S390_VXRS_LOW);
125     for (i = 0; i <= 15; i++) {
126         note->contents.vregslo.vregs[i] = cpu_to_be64(cpu->env.vregs[i][1]);
127     }
128 }
129 
130 static void s390x_write_elf64_vregshi(Note *note, S390CPU *cpu, int id)
131 {
132     int i;
133     S390xElfVregsHi *temp_vregshi;
134 
135     temp_vregshi = &note->contents.vregshi;
136 
137     note->hdr.n_type = cpu_to_be32(NT_S390_VXRS_HIGH);
138     for (i = 0; i <= 15; i++) {
139         temp_vregshi->vregs[i][0] = cpu_to_be64(cpu->env.vregs[i + 16][0]);
140         temp_vregshi->vregs[i][1] = cpu_to_be64(cpu->env.vregs[i + 16][1]);
141     }
142 }
143 
144 static void s390x_write_elf64_gscb(Note *note, S390CPU *cpu, int id)
145 {
146     int i;
147 
148     note->hdr.n_type = cpu_to_be32(NT_S390_GS_CB);
149     for (i = 0; i < 4; i++) {
150         note->contents.gscb.gsregs[i] = cpu_to_be64(cpu->env.gscb[i]);
151     }
152 }
153 
154 static void s390x_write_elf64_timer(Note *note, S390CPU *cpu, int id)
155 {
156     note->hdr.n_type = cpu_to_be32(NT_S390_TIMER);
157     note->contents.timer = cpu_to_be64((uint64_t)(cpu->env.cputm));
158 }
159 
160 static void s390x_write_elf64_todcmp(Note *note, S390CPU *cpu, int id)
161 {
162     note->hdr.n_type = cpu_to_be32(NT_S390_TODCMP);
163     note->contents.todcmp = cpu_to_be64((uint64_t)(cpu->env.ckc));
164 }
165 
166 static void s390x_write_elf64_todpreg(Note *note, S390CPU *cpu, int id)
167 {
168     note->hdr.n_type = cpu_to_be32(NT_S390_TODPREG);
169     note->contents.todpreg = cpu_to_be32((uint32_t)(cpu->env.todpr));
170 }
171 
172 static void s390x_write_elf64_ctrs(Note *note, S390CPU *cpu, int id)
173 {
174     int i;
175 
176     note->hdr.n_type = cpu_to_be32(NT_S390_CTRS);
177 
178     for (i = 0; i <= 15; i++) {
179         note->contents.ctrs[i] = cpu_to_be64(cpu->env.cregs[i]);
180     }
181 }
182 
183 static void s390x_write_elf64_prefix(Note *note, S390CPU *cpu, int id)
184 {
185     note->hdr.n_type = cpu_to_be32(NT_S390_PREFIX);
186     note->contents.prefix = cpu_to_be32((uint32_t)(cpu->env.psa));
187 }
188 
189 static void s390x_write_elf64_pv(Note *note, S390CPU *cpu, int id)
190 {
191     note->hdr.n_type = cpu_to_be32(NT_S390_PV_CPU_DATA);
192     if (!pv_dump_initialized) {
193         return;
194     }
195     kvm_s390_dump_cpu(cpu, &note->contents.dynamic);
196 }
197 
198 typedef struct NoteFuncDescStruct {
199     int contents_size;
200     uint64_t (*note_size_func)(void); /* NULL for non-dynamic sized contents */
201     void (*note_contents_func)(Note *note, S390CPU *cpu, int id);
202     bool pvonly;
203 } NoteFuncDesc;
204 
205 static const NoteFuncDesc note_core[] = {
206     {sizeof_field(Note, contents.prstatus), NULL, s390x_write_elf64_prstatus, false},
207     {sizeof_field(Note, contents.fpregset), NULL, s390x_write_elf64_fpregset, false},
208     { 0, NULL, NULL, false}
209 };
210 
211 static const NoteFuncDesc note_linux[] = {
212     {sizeof_field(Note, contents.prefix),   NULL, s390x_write_elf64_prefix,  false},
213     {sizeof_field(Note, contents.ctrs),     NULL, s390x_write_elf64_ctrs,    false},
214     {sizeof_field(Note, contents.timer),    NULL, s390x_write_elf64_timer,   false},
215     {sizeof_field(Note, contents.todcmp),   NULL, s390x_write_elf64_todcmp,  false},
216     {sizeof_field(Note, contents.todpreg),  NULL, s390x_write_elf64_todpreg, false},
217     {sizeof_field(Note, contents.vregslo),  NULL, s390x_write_elf64_vregslo, false},
218     {sizeof_field(Note, contents.vregshi),  NULL, s390x_write_elf64_vregshi, false},
219     {sizeof_field(Note, contents.gscb),     NULL, s390x_write_elf64_gscb,    false},
220     {0, kvm_s390_pv_dmp_get_size_cpu,       s390x_write_elf64_pv, true},
221     { 0, NULL, NULL, false}
222 };
223 
224 static int s390x_write_elf64_notes(const char *note_name,
225                                        WriteCoreDumpFunction f,
226                                        S390CPU *cpu, int id,
227                                        DumpState *s,
228                                        const NoteFuncDesc *funcs)
229 {
230     Note note, *notep;
231     const NoteFuncDesc *nf;
232     int note_size, content_size;
233     int ret = -1;
234 
235     assert(strlen(note_name) < sizeof(note.name));
236 
237     for (nf = funcs; nf->note_contents_func; nf++) {
238         notep = &note;
239         if (nf->pvonly && !s390_is_pv()) {
240             continue;
241         }
242 
243         content_size = nf->note_size_func ? nf->note_size_func() : nf->contents_size;
244         note_size = sizeof(note) - sizeof(notep->contents) + content_size;
245 
246         /* Notes with dynamic sizes need to allocate a note */
247         if (nf->note_size_func) {
248             notep = g_malloc(note_size);
249         }
250 
251         memset(notep, 0, sizeof(note));
252 
253         /* Setup note header data */
254         notep->hdr.n_descsz = cpu_to_be32(content_size);
255         notep->hdr.n_namesz = cpu_to_be32(strlen(note_name) + 1);
256         g_strlcpy(notep->name, note_name, sizeof(notep->name));
257 
258         /* Get contents and write them out */
259         (*nf->note_contents_func)(notep, cpu, id);
260         ret = f(notep, note_size, s);
261 
262         if (nf->note_size_func) {
263             g_free(notep);
264         }
265 
266         if (ret < 0) {
267             return -1;
268         }
269 
270     }
271 
272     return 0;
273 }
274 
275 
276 int s390_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
277                               int cpuid, DumpState *s)
278 {
279     S390CPU *cpu = S390_CPU(cs);
280     int r;
281 
282     r = s390x_write_elf64_notes("CORE", f, cpu, cpuid, s, note_core);
283     if (r) {
284         return r;
285     }
286     return s390x_write_elf64_notes("LINUX", f, cpu, cpuid, s, note_linux);
287 }
288 
289 /* PV dump section size functions */
290 static uint64_t get_mem_state_size_from_len(uint64_t len)
291 {
292     return (len / (MiB)) * kvm_s390_pv_dmp_get_size_mem_state();
293 }
294 
295 static uint64_t get_size_mem_state(DumpState *s)
296 {
297     return get_mem_state_size_from_len(s->total_size);
298 }
299 
300 static uint64_t get_size_completion_data(DumpState *s)
301 {
302     return kvm_s390_pv_dmp_get_size_completion_data();
303 }
304 
305 /* PV dump section data functions*/
306 static int get_data_completion(DumpState *s, uint8_t *buff)
307 {
308     int rc;
309 
310     if (!pv_dump_initialized) {
311         return 0;
312     }
313     rc = kvm_s390_dump_completion_data(buff);
314     if (!rc) {
315             pv_dump_initialized = false;
316     }
317     return rc;
318 }
319 
320 static int get_mem_state(DumpState *s, uint8_t *buff)
321 {
322     int64_t memblock_size, memblock_start;
323     GuestPhysBlock *block;
324     uint64_t off;
325     int rc;
326 
327     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
328         memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin,
329                                                       s->filter_area_length);
330         if (memblock_start == -1) {
331             continue;
332         }
333 
334         memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin,
335                                                     s->filter_area_length);
336 
337         off = get_mem_state_size_from_len(block->target_start);
338 
339         rc = kvm_s390_dump_mem_state(block->target_start,
340                                      get_mem_state_size_from_len(memblock_size),
341                                      buff + off);
342         if (rc) {
343             return rc;
344         }
345     }
346 
347     return 0;
348 }
349 
350 static struct sections {
351     uint64_t (*sections_size_func)(DumpState *s);
352     int (*sections_contents_func)(DumpState *s, uint8_t *buff);
353     char sctn_str[12];
354 } sections[] = {
355     { get_size_mem_state, get_mem_state, "pv_mem_meta"},
356     { get_size_completion_data, get_data_completion, "pv_compl"},
357     {NULL , NULL, ""}
358 };
359 
360 static uint64_t arch_sections_write_hdr(DumpState *s, uint8_t *buff)
361 {
362     Elf64_Shdr *shdr = (void *)buff;
363     struct sections *sctn = sections;
364     uint64_t off = s->section_offset;
365 
366     if (!pv_dump_initialized) {
367         return 0;
368     }
369 
370     for (; sctn->sections_size_func; off += shdr->sh_size, sctn++, shdr++) {
371         memset(shdr, 0, sizeof(*shdr));
372         shdr->sh_type = SHT_PROGBITS;
373         shdr->sh_offset = off;
374         shdr->sh_size = sctn->sections_size_func(s);
375         shdr->sh_name = s->string_table_buf->len;
376         g_array_append_vals(s->string_table_buf, sctn->sctn_str, sizeof(sctn->sctn_str));
377     }
378 
379     return (uintptr_t)shdr - (uintptr_t)buff;
380 }
381 
382 
383 /* Add arch specific number of sections and their respective sizes */
384 static void arch_sections_add(DumpState *s)
385 {
386     struct sections *sctn = sections;
387 
388     /*
389      * We only do a PV dump if we are running a PV guest, KVM supports
390      * the dump API and we got valid dump length information.
391      */
392     if (!s390_is_pv() || !kvm_s390_get_protected_dump() ||
393         !kvm_s390_pv_info_basic_valid()) {
394         return;
395     }
396 
397     /*
398      * Start the UV dump process by doing the initialize dump call via
399      * KVM as the proxy.
400      */
401     if (!kvm_s390_dump_init()) {
402         pv_dump_initialized = true;
403     } else {
404         /*
405          * Dump init failed, maybe the guest owner disabled dumping.
406          * We'll continue the non-PV dump process since this is no
407          * reason to crash qemu.
408          */
409         return;
410     }
411 
412     for (; sctn->sections_size_func; sctn++) {
413         s->shdr_num += 1;
414         s->elf_section_data_size += sctn->sections_size_func(s);
415     }
416 }
417 
418 /*
419  * After the PV dump has been initialized, the CPU data has been
420  * fetched and memory has been dumped, we need to grab the tweak data
421  * and the completion data.
422  */
423 static int arch_sections_write(DumpState *s, uint8_t *buff)
424 {
425     struct sections *sctn = sections;
426     int rc;
427 
428     if (!pv_dump_initialized) {
429         return -EINVAL;
430     }
431 
432     for (; sctn->sections_size_func; sctn++) {
433         rc = sctn->sections_contents_func(s, buff);
434         buff += sctn->sections_size_func(s);
435         if (rc) {
436             return rc;
437         }
438     }
439     return 0;
440 }
441 
442 int cpu_get_dump_info(ArchDumpInfo *info,
443                       const struct GuestPhysBlockList *guest_phys_blocks)
444 {
445     info->d_machine = EM_S390;
446     info->d_endian = ELFDATA2MSB;
447     info->d_class = ELFCLASS64;
448     /*
449      * This is evaluated for each dump so we can freely switch
450      * between PV and non-PV.
451      */
452     if (s390_is_pv() && kvm_s390_get_protected_dump() &&
453         kvm_s390_pv_info_basic_valid()) {
454         info->arch_sections_add_fn = *arch_sections_add;
455         info->arch_sections_write_hdr_fn = *arch_sections_write_hdr;
456         info->arch_sections_write_fn = *arch_sections_write;
457     } else {
458         info->arch_sections_add_fn = NULL;
459         info->arch_sections_write_hdr_fn = NULL;
460         info->arch_sections_write_fn = NULL;
461     }
462     return 0;
463 }
464 
465 ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
466 {
467     int name_size = 8; /* "LINUX" or "CORE" + pad */
468     size_t elf_note_size = 0;
469     int note_head_size, content_size;
470     const NoteFuncDesc *nf;
471 
472     assert(class == ELFCLASS64);
473     assert(machine == EM_S390);
474 
475     note_head_size = sizeof(Elf64_Nhdr);
476 
477     for (nf = note_core; nf->note_contents_func; nf++) {
478         elf_note_size = elf_note_size + note_head_size + name_size + nf->contents_size;
479     }
480     for (nf = note_linux; nf->note_contents_func; nf++) {
481         if (nf->pvonly && !s390_is_pv()) {
482             continue;
483         }
484         content_size = nf->contents_size ? nf->contents_size : nf->note_size_func();
485         elf_note_size = elf_note_size + note_head_size + name_size +
486                         content_size;
487     }
488 
489     return (elf_note_size) * nr_cpus;
490 }
491