target-i386: Add API to get note's size

We should know where the note and memory is stored before writing
them to vmcore. If we know this, we can avoid using lseek() when
creating vmcore.

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

diff --git a/cpu-all.h b/cpu-all.h
index 7e07c9127520db610c2990930ad9ce2f337f4fe6..2b77f66b35c9707bff29dbad2375f41af071017e 100644 (file)
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -553,6 +553,7 @@ int cpu_write_elf64_qemunote(write_core_dump_function f, CPUArchState *env,
 int cpu_write_elf32_qemunote(write_core_dump_function f, CPUArchState *env,
                              void *opaque);
 int cpu_get_dump_info(ArchDumpInfo *info);
+size_t cpu_get_note_size(int class, int machine, int nr_cpus);
 #else
 static inline int cpu_write_elf64_note(write_core_dump_function f,
                                        CPUArchState *env, int cpuid,
@@ -586,6 +587,11 @@ static inline int cpu_get_dump_info(ArchDumpInfo *info)
 {
     return -1;
 }
+
+static inline int cpu_get_note_size(int class, int machine, int nr_cpus)
+{
+    return -1;
+}
 #endif
 
 #endif /* CPU_ALL_H */

diff --git a/target-i386/arch_dump.c b/target-i386/arch_dump.c
index e37857968d6d378c95d78b599c976a0a8105fafc..135d855c4adb574ca02c19e75cd8908f19f27c91 100644 (file)
--- a/target-i386/arch_dump.c
+++ b/target-i386/arch_dump.c
@@ -414,3 +414,36 @@ int cpu_get_dump_info(ArchDumpInfo *info)
 
     return 0;
 }
+
+size_t cpu_get_note_size(int class, int machine, int nr_cpus)
+{
+    int name_size = 5; /* "CORE" or "QEMU" */
+    size_t elf_note_size = 0;
+    size_t qemu_note_size = 0;
+    int elf_desc_size = 0;
+    int qemu_desc_size = 0;
+    int note_head_size;
+
+    if (class == ELFCLASS32) {
+        note_head_size = sizeof(Elf32_Nhdr);
+    } else {
+        note_head_size = sizeof(Elf64_Nhdr);
+    }
+
+    if (machine == EM_386) {
+        elf_desc_size = sizeof(x86_elf_prstatus);
+    }
+#ifdef TARGET_X86_64
+    else {
+        elf_desc_size = sizeof(x86_64_elf_prstatus);
+    }
+#endif
+    qemu_desc_size = sizeof(QEMUCPUState);
+
+    elf_note_size = ((note_head_size + 3) / 4 + (name_size + 3) / 4 +
+                     (elf_desc_size + 3) / 4) * 4;
+    qemu_note_size = ((note_head_size + 3) / 4 + (name_size + 3) / 4 +
+                      (qemu_desc_size + 3) / 4) * 4;
+
+    return (elf_note_size + qemu_note_size) * nr_cpus;
+}