xref: /openbmc/qemu/target/s390x/arch_dump.c (revision 87c9d801)
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 "kvm/kvm_s390x.h"
21 #include "target/s390x/kvm/pv.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 
s390x_write_elf64_prstatus(Note * note,S390CPU * cpu,int id)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 = cpu_to_be32(id);
106 }
107 
s390x_write_elf64_fpregset(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_vregslo(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_vregshi(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_gscb(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_timer(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_todcmp(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_todpreg(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_ctrs(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_prefix(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_pv(Note * note,S390CPU * cpu,int id)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 
s390x_write_elf64_notes(const char * note_name,WriteCoreDumpFunction f,S390CPU * cpu,int id,DumpState * s,const NoteFuncDesc * funcs)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     g_autofree Note *notep = NULL;
231     const NoteFuncDesc *nf;
232     int note_size, prev_size = 0, content_size;
233     int ret = -1;
234 
235     assert(strlen(note_name) < sizeof(notep->name));
236 
237     for (nf = funcs; nf->note_contents_func; nf++) {
238         if (nf->pvonly && !s390_is_pv()) {
239             continue;
240         }
241 
242         content_size = nf->note_size_func ? nf->note_size_func() : nf->contents_size;
243         note_size = sizeof(Note) - sizeof(notep->contents) + content_size;
244 
245         if (prev_size < note_size) {
246             g_free(notep);
247             notep = g_malloc(note_size);
248             prev_size = note_size;
249         }
250 
251         memset(notep, 0, note_size);
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         if (ret < 0) {
262             return -1;
263         }
264     }
265 
266     return 0;
267 }
268 
269 
s390_cpu_write_elf64_note(WriteCoreDumpFunction f,CPUState * cs,int cpuid,DumpState * s)270 int s390_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
271                               int cpuid, DumpState *s)
272 {
273     S390CPU *cpu = S390_CPU(cs);
274     int r;
275 
276     r = s390x_write_elf64_notes("CORE", f, cpu, cpuid, s, note_core);
277     if (r) {
278         return r;
279     }
280     return s390x_write_elf64_notes("LINUX", f, cpu, cpuid, s, note_linux);
281 }
282 
283 /* PV dump section size functions */
get_mem_state_size_from_len(uint64_t len)284 static uint64_t get_mem_state_size_from_len(uint64_t len)
285 {
286     return (len / (MiB)) * kvm_s390_pv_dmp_get_size_mem_state();
287 }
288 
get_size_mem_state(DumpState * s)289 static uint64_t get_size_mem_state(DumpState *s)
290 {
291     return get_mem_state_size_from_len(s->total_size);
292 }
293 
get_size_completion_data(DumpState * s)294 static uint64_t get_size_completion_data(DumpState *s)
295 {
296     return kvm_s390_pv_dmp_get_size_completion_data();
297 }
298 
299 /* PV dump section data functions*/
get_data_completion(DumpState * s,uint8_t * buff)300 static int get_data_completion(DumpState *s, uint8_t *buff)
301 {
302     int rc;
303 
304     if (!pv_dump_initialized) {
305         return 0;
306     }
307     rc = kvm_s390_dump_completion_data(buff);
308     if (!rc) {
309             pv_dump_initialized = false;
310     }
311     return rc;
312 }
313 
get_mem_state(DumpState * s,uint8_t * buff)314 static int get_mem_state(DumpState *s, uint8_t *buff)
315 {
316     int64_t memblock_size, memblock_start;
317     GuestPhysBlock *block;
318     uint64_t off;
319     int rc;
320 
321     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
322         memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin,
323                                                       s->filter_area_length);
324         if (memblock_start == -1) {
325             continue;
326         }
327 
328         memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin,
329                                                     s->filter_area_length);
330 
331         off = get_mem_state_size_from_len(block->target_start);
332 
333         rc = kvm_s390_dump_mem_state(block->target_start,
334                                      get_mem_state_size_from_len(memblock_size),
335                                      buff + off);
336         if (rc) {
337             return rc;
338         }
339     }
340 
341     return 0;
342 }
343 
344 static struct sections {
345     uint64_t (*sections_size_func)(DumpState *s);
346     int (*sections_contents_func)(DumpState *s, uint8_t *buff);
347     char sctn_str[12];
348 } sections[] = {
349     { get_size_mem_state, get_mem_state, "pv_mem_meta"},
350     { get_size_completion_data, get_data_completion, "pv_compl"},
351     {NULL , NULL, ""}
352 };
353 
arch_sections_write_hdr(DumpState * s,uint8_t * buff)354 static uint64_t arch_sections_write_hdr(DumpState *s, uint8_t *buff)
355 {
356     Elf64_Shdr *shdr = (void *)buff;
357     struct sections *sctn = sections;
358     uint64_t off = s->section_offset;
359 
360     if (!pv_dump_initialized) {
361         return 0;
362     }
363 
364     for (; sctn->sections_size_func; off += shdr->sh_size, sctn++, shdr++) {
365         memset(shdr, 0, sizeof(*shdr));
366         shdr->sh_type = SHT_PROGBITS;
367         shdr->sh_offset = off;
368         shdr->sh_size = sctn->sections_size_func(s);
369         shdr->sh_name = s->string_table_buf->len;
370         g_array_append_vals(s->string_table_buf, sctn->sctn_str, sizeof(sctn->sctn_str));
371     }
372 
373     return (uintptr_t)shdr - (uintptr_t)buff;
374 }
375 
376 
377 /* Add arch specific number of sections and their respective sizes */
arch_sections_add(DumpState * s)378 static void arch_sections_add(DumpState *s)
379 {
380     struct sections *sctn = sections;
381 
382     /*
383      * We only do a PV dump if we are running a PV guest, KVM supports
384      * the dump API and we got valid dump length information.
385      */
386     if (!s390_is_pv() || !kvm_s390_get_protected_dump() ||
387         !kvm_s390_pv_info_basic_valid()) {
388         return;
389     }
390 
391     /*
392      * Start the UV dump process by doing the initialize dump call via
393      * KVM as the proxy.
394      */
395     if (!kvm_s390_dump_init()) {
396         pv_dump_initialized = true;
397     } else {
398         /*
399          * Dump init failed, maybe the guest owner disabled dumping.
400          * We'll continue the non-PV dump process since this is no
401          * reason to crash qemu.
402          */
403         return;
404     }
405 
406     for (; sctn->sections_size_func; sctn++) {
407         s->shdr_num += 1;
408         s->elf_section_data_size += sctn->sections_size_func(s);
409     }
410 }
411 
412 /*
413  * After the PV dump has been initialized, the CPU data has been
414  * fetched and memory has been dumped, we need to grab the tweak data
415  * and the completion data.
416  */
arch_sections_write(DumpState * s,uint8_t * buff)417 static int arch_sections_write(DumpState *s, uint8_t *buff)
418 {
419     struct sections *sctn = sections;
420     int rc;
421 
422     if (!pv_dump_initialized) {
423         return -EINVAL;
424     }
425 
426     for (; sctn->sections_size_func; sctn++) {
427         rc = sctn->sections_contents_func(s, buff);
428         buff += sctn->sections_size_func(s);
429         if (rc) {
430             return rc;
431         }
432     }
433     return 0;
434 }
435 
arch_cleanup(DumpState * s)436 static void arch_cleanup(DumpState *s)
437 {
438     g_autofree uint8_t *buff = NULL;
439     int rc;
440 
441     if (!pv_dump_initialized) {
442         return;
443     }
444 
445     buff = g_malloc(kvm_s390_pv_dmp_get_size_completion_data());
446     rc = kvm_s390_dump_completion_data(buff);
447     if (!rc) {
448             pv_dump_initialized = false;
449     }
450 }
451 
cpu_get_dump_info(ArchDumpInfo * info,const struct GuestPhysBlockList * guest_phys_blocks)452 int cpu_get_dump_info(ArchDumpInfo *info,
453                       const struct GuestPhysBlockList *guest_phys_blocks)
454 {
455     info->d_machine = EM_S390;
456     info->d_endian = ELFDATA2MSB;
457     info->d_class = ELFCLASS64;
458     /*
459      * This is evaluated for each dump so we can freely switch
460      * between PV and non-PV.
461      */
462     if (s390_is_pv() && kvm_s390_get_protected_dump() &&
463         kvm_s390_pv_info_basic_valid()) {
464         info->arch_sections_add_fn = *arch_sections_add;
465         info->arch_sections_write_hdr_fn = *arch_sections_write_hdr;
466         info->arch_sections_write_fn = *arch_sections_write;
467         info->arch_cleanup_fn = *arch_cleanup;
468     }
469     return 0;
470 }
471 
cpu_get_note_size(int class,int machine,int nr_cpus)472 ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
473 {
474     int name_size = 8; /* "LINUX" or "CORE" + pad */
475     size_t elf_note_size = 0;
476     int note_head_size, content_size;
477     const NoteFuncDesc *nf;
478 
479     assert(class == ELFCLASS64);
480     assert(machine == EM_S390);
481 
482     note_head_size = sizeof(Elf64_Nhdr);
483 
484     for (nf = note_core; nf->note_contents_func; nf++) {
485         elf_note_size = elf_note_size + note_head_size + name_size + nf->contents_size;
486     }
487     for (nf = note_linux; nf->note_contents_func; nf++) {
488         if (nf->pvonly && !s390_is_pv()) {
489             continue;
490         }
491         content_size = nf->contents_size ? nf->contents_size : nf->note_size_func();
492         elf_note_size = elf_note_size + note_head_size + name_size +
493                         content_size;
494     }
495 
496     return (elf_note_size) * nr_cpus;
497 }
498