target-i386: Add API to write cpu status to core file

The core file has register's value. But it does not include all registers value.
Store the cpu status into QEMU note, and the user can get more information
from vmcore. If you change QEMUCPUState, please count up QEMUCPUSTATE_VERSION.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

cpu-all.h

@@ -547,6 +547,10 @@ int cpu_write_elf64_note(write_core_dump_function f, CPUArchState *env,
                          int cpuid, void *opaque);
 int cpu_write_elf32_note(write_core_dump_function f, CPUArchState *env,
                          int cpuid, void *opaque);
+int cpu_write_elf64_qemunote(write_core_dump_function f, CPUArchState *env,
+                             void *opaque);
+int cpu_write_elf32_qemunote(write_core_dump_function f, CPUArchState *env,
+                             void *opaque);
 #else
 static inline int cpu_write_elf64_note(write_core_dump_function f,
                                        CPUArchState *env, int cpuid,
@@ -561,6 +565,20 @@ static inline int cpu_write_elf32_note(write_core_dump_function f,
 {
     return -1;
 }
+
+static inline int cpu_write_elf64_qemunote(write_core_dump_function f,
+                                           CPUArchState *env,
+                                           void *opaque)
+{
+    return -1;
+}
+
+static inline int cpu_write_elf32_qemunote(write_core_dump_function f,
+                                           CPUArchState *env,
+                                           void *opaque)
+{
+    return -1;
+}
 #endif
 
 #endif /* CPU_ALL_H */

target-i386/arch_dump.c

@@ -231,3 +231,152 @@ int cpu_write_elf32_note(write_core_dump_function f, CPUArchState *env,
 
     return 0;
 }
+
+/*
+ * please count up QEMUCPUSTATE_VERSION if you have changed definition of
+ * QEMUCPUState, and modify the tools using this information accordingly.
+ */
+#define QEMUCPUSTATE_VERSION (1)
+
+struct QEMUCPUSegment {
+    uint32_t selector;
+    uint32_t limit;
+    uint32_t flags;
+    uint32_t pad;
+    uint64_t base;
+};
+
+typedef struct QEMUCPUSegment QEMUCPUSegment;
+
+struct QEMUCPUState {
+    uint32_t version;
+    uint32_t size;
+    uint64_t rax, rbx, rcx, rdx, rsi, rdi, rsp, rbp;
+    uint64_t r8, r9, r10, r11, r12, r13, r14, r15;
+    uint64_t rip, rflags;
+    QEMUCPUSegment cs, ds, es, fs, gs, ss;
+    QEMUCPUSegment ldt, tr, gdt, idt;
+    uint64_t cr[5];
+};
+
+typedef struct QEMUCPUState QEMUCPUState;
+
+static void copy_segment(QEMUCPUSegment *d, SegmentCache *s)
+{
+    d->pad = 0;
+    d->selector = s->selector;
+    d->limit = s->limit;
+    d->flags = s->flags;
+    d->base = s->base;
+}
+
+static void qemu_get_cpustate(QEMUCPUState *s, CPUArchState *env)
+{
+    memset(s, 0, sizeof(QEMUCPUState));
+
+    s->version = QEMUCPUSTATE_VERSION;
+    s->size = sizeof(QEMUCPUState);
+
+    s->rax = env->regs[R_EAX];
+    s->rbx = env->regs[R_EBX];
+    s->rcx = env->regs[R_ECX];
+    s->rdx = env->regs[R_EDX];
+    s->rsi = env->regs[R_ESI];
+    s->rdi = env->regs[R_EDI];
+    s->rsp = env->regs[R_ESP];
+    s->rbp = env->regs[R_EBP];
+#ifdef TARGET_X86_64
+    s->r8  = env->regs[8];
+    s->r9  = env->regs[9];
+    s->r10 = env->regs[10];
+    s->r11 = env->regs[11];
+    s->r12 = env->regs[12];
+    s->r13 = env->regs[13];
+    s->r14 = env->regs[14];
+    s->r15 = env->regs[15];
+#endif
+    s->rip = env->eip;
+    s->rflags = env->eflags;
+
+    copy_segment(&s->cs, &env->segs[R_CS]);
+    copy_segment(&s->ds, &env->segs[R_DS]);
+    copy_segment(&s->es, &env->segs[R_ES]);
+    copy_segment(&s->fs, &env->segs[R_FS]);
+    copy_segment(&s->gs, &env->segs[R_GS]);
+    copy_segment(&s->ss, &env->segs[R_SS]);
+    copy_segment(&s->ldt, &env->ldt);
+    copy_segment(&s->tr, &env->tr);
+    copy_segment(&s->gdt, &env->gdt);
+    copy_segment(&s->idt, &env->idt);
+
+    s->cr[0] = env->cr[0];
+    s->cr[1] = env->cr[1];
+    s->cr[2] = env->cr[2];
+    s->cr[3] = env->cr[3];
+    s->cr[4] = env->cr[4];
+}
+
+static inline int cpu_write_qemu_note(write_core_dump_function f,
+                                      CPUArchState *env,
+                                      void *opaque,
+                                      int type)
+{
+    QEMUCPUState state;
+    Elf64_Nhdr *note64;
+    Elf32_Nhdr *note32;
+    void *note;
+    char *buf;
+    int descsz, note_size, name_size = 5, note_head_size;
+    const char *name = "QEMU";
+    int ret;
+
+    qemu_get_cpustate(&state, env);
+
+    descsz = sizeof(state);
+    if (type == 0) {
+        note_head_size = sizeof(Elf32_Nhdr);
+    } else {
+        note_head_size = sizeof(Elf64_Nhdr);
+    }
+    note_size = ((note_head_size + 3) / 4 + (name_size + 3) / 4 +
+                (descsz + 3) / 4) * 4;
+    note = g_malloc(note_size);
+
+    memset(note, 0, note_size);
+    if (type == 0) {
+        note32 = note;
+        note32->n_namesz = cpu_to_le32(name_size);
+        note32->n_descsz = cpu_to_le32(descsz);
+        note32->n_type = 0;
+    } else {
+        note64 = note;
+        note64->n_namesz = cpu_to_le32(name_size);
+        note64->n_descsz = cpu_to_le32(descsz);
+        note64->n_type = 0;
+    }
+    buf = note;
+    buf += ((note_head_size + 3) / 4) * 4;
+    memcpy(buf, name, name_size);
+    buf += ((name_size + 3) / 4) * 4;
+    memcpy(buf, &state, sizeof(state));
+
+    ret = f(note, note_size, opaque);
+    g_free(note);
+    if (ret < 0) {
+        return -1;
+    }
+
+    return 0;
+}
+
+int cpu_write_elf64_qemunote(write_core_dump_function f, CPUArchState *env,
+                             void *opaque)
+{
+    return cpu_write_qemu_note(f, env, opaque, 1);
+}
+
+int cpu_write_elf32_qemunote(write_core_dump_function f, CPUArchState *env,
+                             void *opaque)
+{
+    return cpu_write_qemu_note(f, env, opaque, 0);
+}