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>

1 files changed, 33 insertions, 0 deletions

diff --git a/target-i386/arch_dump.c b/target-i386/arch_dump.c
index e378579..135d855 100644
--- 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;
+}