[Qemu-devel] [RFC] s390: dump-guest-memory implementation for s390x arch.

[Jens Freimann]

From: Ekaterina Tumanova <address@hidden>

dump-guest-memory QEMU monitor command didn't work for s390 architecture.
The result of the command is supposed to be ELF format crash-readable
dump.
In order to implement this, the arch-specific part of dump-guest-memory
was added:
target-s390x/arch_dump.c contains the whole set of function for writing
Elf note sections of all types for s390x.
target-s390x/arch_memory_mapping.c contains stub functions, current
patch places all guest physical memory into the dump.

Signed-off-by: Ekaterina Tumanova <address@hidden>
Signed-off-by: Jens Freimann <address@hidden>

---
 configure                          |   4 +-
 include/elf.h                      |   6 +
 target-s390x/Makefile.objs         |   2 +-
 target-s390x/arch_dump.c           | 240 +++++++++++++++++++++++++++++++++++++
 target-s390x/arch_memory_mapping.c |  26 ++++
 5 files changed, 275 insertions(+), 3 deletions(-)
 create mode 100644 target-s390x/arch_dump.c
 create mode 100644 target-s390x/arch_memory_mapping.c

diff --git a/configure b/configure
index 19738ac..938be14 100755
--- a/configure
+++ b/configure
@@ -4146,7 +4146,7 @@ case "$target_arch2" in
     fi
 esac
 case "$target_arch2" in
-  i386|x86_64)
+  i386|x86_64|s390x)
     echo "CONFIG_HAVE_GET_MEMORY_MAPPING=y" >> $config_target_mak
 esac
 if test "$target_arch2" = "ppc64" -a "$fdt" = "yes"; then
@@ -4159,7 +4159,7 @@ if test "$target_softmmu" = "yes" ; then
   echo "CONFIG_SOFTMMU=y" >> $config_target_mak
   echo "LIBS+=$libs_softmmu $target_libs_softmmu" >> $config_target_mak
   case "$target_arch2" in
-    i386|x86_64)
+    i386|x86_64|s390x)
       echo "CONFIG_HAVE_CORE_DUMP=y" >> $config_target_mak
   esac
 fi
diff --git a/include/elf.h b/include/elf.h
index a21ea53..ba4b3a7 100644
--- a/include/elf.h
+++ b/include/elf.h
@@ -1219,11 +1219,17 @@ typedef struct elf64_shdr {
 
 /* Notes used in ET_CORE */
 #define NT_PRSTATUS    1
+#define NT_FPREGSET     2
 #define NT_PRFPREG     2
 #define NT_PRPSINFO    3
 #define NT_TASKSTRUCT  4
 #define NT_AUXV                6
 #define NT_PRXFPREG     0x46e62b7f      /* copied from 
gdb5.1/include/elf/common.h */
+#define NT_S390_PREFIX  0x305           /* s390 prefix register */
+#define NT_S390_CTRS    0x304           /* s390 control registers */
+#define NT_S390_TODPREG 0x303           /* s390 TOD programmable register */
+#define NT_S390_TODCMP  0x302           /* s390 TOD clock comparator register 
*/
+#define NT_S390_TIMER   0x301           /* s390 timer register */
 
 
 /* Note header in a PT_NOTE section */
diff --git a/target-s390x/Makefile.objs b/target-s390x/Makefile.objs
index 4e63417..82c79c4 100644
--- a/target-s390x/Makefile.objs
+++ b/target-s390x/Makefile.objs
@@ -1,4 +1,4 @@
 obj-y += translate.o helper.o cpu.o interrupt.o
 obj-y += int_helper.o fpu_helper.o cc_helper.o mem_helper.o misc_helper.o
-obj-$(CONFIG_SOFTMMU) += ioinst.o
+obj-$(CONFIG_SOFTMMU) += ioinst.o arch_dump.o arch_memory_mapping.o
 obj-$(CONFIG_KVM) += kvm.o
diff --git a/target-s390x/arch_dump.c b/target-s390x/arch_dump.c
new file mode 100644
index 0000000..3098cd1
--- /dev/null
+++ b/target-s390x/arch_dump.c
@@ -0,0 +1,240 @@
+/*
+ * writing ELF notes for s390x arch
+ *
+ *  
+ * Copyright IBM Corp. 2012
+ *
+ *     Ekaterina Tumanova <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "cpu.h"
+#include "elf.h"
+#include "exec/cpu-all.h"
+#include "sysemu/dump.h"
+#include "sysemu/kvm.h"
+
+
+struct s390x_user_regs_struct {
+    uint64_t        psw[2];
+    uint64_t        gprs[16];
+    uint32_t        acrs[16];
+} QEMU_PACKED;
+
+typedef struct s390x_user_regs_struct s390x_user_regs;
+
+struct s390x_elf_prstatus_struct {
+    uint8_t pad1[32];
+    uint32_t pid;
+    uint8_t pad2[76];
+    s390x_user_regs regs;
+    uint8_t pad3[16];
+} QEMU_PACKED;
+
+typedef struct s390x_elf_prstatus_struct s390x_elf_prstatus;
+
+struct s390x_elf_fpregset_struct {
+        uint32_t        fpc;
+        uint32_t        pad;
+        uint64_t        fprs[16];
+} QEMU_PACKED;
+
+typedef struct s390x_elf_fpregset_struct s390x_elf_fpregset;
+
+    typedef struct note_struct {
+        Elf64_Nhdr hdr;
+        char name[5];
+        char pad3[3];
+       union {
+            s390x_elf_prstatus prstatus;
+            s390x_elf_fpregset fpregset;
+            uint32_t prefix;
+            uint64_t timer;
+            uint64_t todcmp;
+            uint32_t todpreg;
+            uint64_t ctrs[16];
+        } contents;
+    } QEMU_PACKED note_t;
+
+static int s390x_write_elf64_prstatus(note_t *note, CPUArchState *env)
+{
+    int i;
+    s390x_user_regs *regs;
+
+    note->hdr.n_type = cpu_to_be32(NT_PRSTATUS);
+
+    regs = &(note->contents.prstatus.regs);
+    regs->psw[0] =  cpu_to_be32(env->psw.mask);
+    regs->psw[1] =  cpu_to_be32(env->psw.addr);
+    for (i = 0; i <= 15; i++) {
+        regs->acrs[i] = cpu_to_be32(env->aregs[i]);
+        regs->gprs[i] = cpu_to_be32(env->regs[i]);
+    }
+
+    return 0;
+}
+
+static int s390x_write_elf64_fpregset(note_t *note, CPUArchState *env)
+{
+    int i;
+
+    note->hdr.n_type = cpu_to_be32(NT_FPREGSET);
+
+    note->contents.fpregset.fpc = cpu_to_be32(env->fpc);
+    for (i = 0; i <= 15; i++) {
+        note->contents.fpregset.fprs[i] =  cpu_to_be64(env->fregs[i].ll);
+    }
+
+    return 0;
+}
+
+
+static int s390x_write_elf64_timer(note_t *note, CPUArchState *env)
+{
+    note->hdr.n_type = cpu_to_be32(NT_S390_TIMER);
+
+    note->contents.timer = cpu_to_be64((uint64_t)(env->cputm));
+
+    return 0;
+}
+
+static int s390x_write_elf64_todcmp(note_t *note, CPUArchState *env)
+{
+    note->hdr.n_type = cpu_to_be32(NT_S390_TODCMP);
+
+    note->contents.todcmp = cpu_to_be64((uint64_t)(env->ckc));
+
+    return 0;
+}
+
+static int s390x_write_elf64_todpreg(note_t *note, CPUArchState *env)
+{
+    note->hdr.n_type = cpu_to_be32(NT_S390_TODPREG);
+
+    note->contents.todpreg = cpu_to_be32((uint32_t)(env->todpr));
+
+    return 0;
+}
+
+static int s390x_write_elf64_ctrs(note_t *note, CPUArchState *env)
+{
+    int i;
+
+    note->hdr.n_type = cpu_to_be32(NT_S390_CTRS);
+
+    for (i = 0; i <= 15; i++) {
+        note->contents.ctrs[i] =  cpu_to_be32(env->cregs[i]);
+    }
+
+    return 0;
+}
+
+static int s390x_write_elf64_prefix(note_t *note, CPUArchState *env)
+{
+    note->hdr.n_type = cpu_to_be32(NT_S390_PREFIX);
+
+    note->contents.prefix = cpu_to_be32((uint32_t)(env->psa));
+
+    return 0;
+}
+
+
+struct note_func_desc_struct {
+    int contents_size;
+    int (*note_contents_func)(note_t *note, CPUArchState *env);
+} note_func[] = {
+                   { sizeof(((note_t *)0)->contents.prstatus), 
s390x_write_elf64_prstatus },
+                   { sizeof(((note_t *)0)->contents.prefix),   
s390x_write_elf64_prefix },
+                   { sizeof(((note_t *)0)->contents.fpregset), 
s390x_write_elf64_fpregset },
+                   { sizeof(((note_t *)0)->contents.ctrs),     
s390x_write_elf64_ctrs },
+                   { sizeof(((note_t *)0)->contents.timer),    
s390x_write_elf64_timer },
+                   { sizeof(((note_t *)0)->contents.todcmp),   
s390x_write_elf64_todcmp },
+                   { sizeof(((note_t *)0)->contents.todpreg),  
s390x_write_elf64_todpreg },
+                   { 0, NULL}
+                 };
+
+
+static int s390x_write_all_elf64_notes(const char *note_name, 
write_core_dump_function f,
+                                   CPUArchState *env, int id,
+                                   void *opaque)
+{
+    note_t note;
+    struct note_func_desc_struct *nf;
+    int note_size;
+    int ret = -1;
+
+    for (nf = note_func; nf->note_contents_func; nf++) {
+        note.hdr.n_namesz = cpu_to_be32(sizeof(note.name));
+        note.hdr.n_descsz = cpu_to_be32(nf->contents_size);
+        strncpy(note.name, note_name, sizeof(note.name));
+        ret = (*nf->note_contents_func)(&note, env);
+
+        note_size = cpu_to_be32(sizeof(note) - sizeof(note.contents) + 
nf->contents_size);
+        ret = f(&note, note_size, opaque);
+
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+
+int cpu_write_elf64_note(write_core_dump_function f, CPUArchState *env,
+                         int cpuid, void *opaque)
+{
+    return s390x_write_all_elf64_notes("CORE", f, env, cpuid, opaque);
+}
+
+int cpu_get_dump_info(ArchDumpInfo *info)
+{
+    info->d_machine = EM_S390;
+    info->d_endian = ELFDATA2MSB;
+    info->d_class = ELFCLASS64;
+
+    return 0;
+}
+
+ssize_t cpu_get_note_size(int class, int machine, int nr_cpus)
+{
+    int name_size = 8; /* "CORE" or "QEMU" rounded*/
+    size_t elf_note_size = 0;
+    int note_head_size;
+    struct note_func_desc_struct *nf;
+
+    assert (class == ELFCLASS64);
+    note_head_size = sizeof(Elf64_Nhdr);
+
+    assert (machine == EM_S390);
+
+    for (nf = note_func; nf->note_contents_func; nf++) {
+         elf_note_size = elf_note_size + note_head_size + name_size + 
nf->contents_size;
+    }
+
+    return (elf_note_size) * nr_cpus;
+
+}
+
+int cpu_write_elf32_note(write_core_dump_function f, CPUArchState *env,
+                         int cpuid, void *opaque)
+{
+    return 0;
+}
+
+
+int cpu_write_elf64_qemunote(write_core_dump_function f, CPUArchState *env,
+                             void *opaque)
+{
+    return 0;
+}
+
+int cpu_write_elf32_qemunote(write_core_dump_function f, CPUArchState *env,
+                             void *opaque)
+{
+    return 0;
+}
+
diff --git a/target-s390x/arch_memory_mapping.c 
b/target-s390x/arch_memory_mapping.c
new file mode 100644
index 0000000..3dad3b9
--- /dev/null
+++ b/target-s390x/arch_memory_mapping.c
@@ -0,0 +1,26 @@
+/*
+ * s390x memory mapping
+ *
+ * Copyright IBM Corp. 2012
+ *
+ * Authors:
+ *     Ekaterina Tumanova <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "cpu.h"
+#include "exec/cpu-all.h"
+#include "sysemu/memory_mapping.h"
+
+int cpu_get_memory_mapping(MemoryMappingList *list, CPUArchState *env)
+{
+    return 0;
+}
+
+bool cpu_paging_enabled(CPUArchState *env)
+{
+    return false;
+}
-- 
1.7.12.4