Re: [Qemu-devel] [PATCH 2/2] s390: dump guest memory implementation

[Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>]

On 04/26/2013 09:12 PM, Alexander Graf wrote:
> On 23.04.2013, at 17:30, Jens Freimann wrote:
>
>> Implement dump-guest-memory support for target s390x.
>>
>> 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.
>>
>> Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
>> Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
>> ---
>> configure                  |   2 +-
>> include/elf.h              |   6 ++
>> target-s390x/Makefile.objs |   2 +-
>> target-s390x/arch_dump.c   | 231 +++++++++++++++++++++++++++++++++++++++++++++
>> target-s390x/cpu-qom.h     |  21 +++++
>> target-s390x/cpu.c         |   7 ++
>> 6 files changed, 267 insertions(+), 2 deletions(-)
>> create mode 100644 target-s390x/arch_dump.c
>>
>> diff --git a/configure b/configure
>> index ed49f91..90dc58b 100755
>> --- a/configure
>> +++ b/configure
>> @@ -4326,7 +4326,7 @@ fi
>> if test "$target_softmmu" = "yes" ; then
>>    echo "CONFIG_SOFTMMU=y" >> $config_target_mak
>>    case "$target_arch2" in
>> -    i386|x86_64)
>> +    i386|x86_64|s390x)
>>        echo "CONFIG_HAVE_CORE_DUMP=y" >> $config_target_mak
>>    esac
>> fi
>> diff --git a/include/elf.h b/include/elf.h
>> index a21ea53..ba4b3a7 100644
>> --- a/include/elf.h
>> +++ b/include/elf.h
>> @@ -1219,11 +1219,17 @@ typedef struct elf64_shdr {
>>
>> /* Notes used in ET_CORE */
>> #define NT_PRSTATUS	1
>> +#define NT_FPREGSET     2
>> #define NT_PRFPREG	2
>> #define NT_PRPSINFO	3
>> #define NT_TASKSTRUCT	4
>> #define NT_AUXV		6
>> #define NT_PRXFPREG     0x46e62b7f      /* copied from gdb5.1/include/elf/common.h */
>> +#define NT_S390_PREFIX  0x305           /* s390 prefix register */
>> +#define NT_S390_CTRS    0x304           /* s390 control registers */
>> +#define NT_S390_TODPREG 0x303           /* s390 TOD programmable register */
>> +#define NT_S390_TODCMP  0x302           /* s390 TOD clock comparator register */
>> +#define NT_S390_TIMER   0x301           /* s390 timer register */
>>
>>
>> /* Note header in a PT_NOTE section */
>> diff --git a/target-s390x/Makefile.objs b/target-s390x/Makefile.objs
>> index 4e63417..c34f654 100644
>> --- a/target-s390x/Makefile.objs
>> +++ b/target-s390x/Makefile.objs
>> @@ -1,4 +1,4 @@
>> obj-y += translate.o helper.o cpu.o interrupt.o
>> obj-y += int_helper.o fpu_helper.o cc_helper.o mem_helper.o misc_helper.o
>> -obj-$(CONFIG_SOFTMMU) += ioinst.o
>> +obj-$(CONFIG_SOFTMMU) += ioinst.o arch_dump.o
>> obj-$(CONFIG_KVM) += kvm.o
>> diff --git a/target-s390x/arch_dump.c b/target-s390x/arch_dump.c
>> new file mode 100644
>> index 0000000..f908257
>> --- /dev/null
>> +++ b/target-s390x/arch_dump.c
>> @@ -0,0 +1,231 @@
>> +/*
>> + * writing ELF notes for s390x arch
>> + *
>> + *
>> + * Copyright IBM Corp. 2012
>> + *
>> + *     Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
>> + *
>> + * 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]);
> be32? Please verify whether you produce proper dumps on a little endian host.
>
>
> Alex
Hi,
I don't think I have an opportunity to test this on x86 host. But 
logically as far as I understand, the code is correct here, since we need
to produce big endian dump for s390 guest for any endian host had, and 
we use cpu_to_be32 in the arch-specific part of code.

Regards,
Kate.
>> +    }
>> +
>> +    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,
>> +            WriteCoreDumpFunction 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 s390_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
>> +                         int cpuid, void *opaque)
>> +{
>> +    S390CPU *cpu = S390_CPU(cs);
>> +    return s390x_write_all_elf64_notes("CORE", f, &cpu->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;
>> +
>> +}
>> +
>> diff --git a/target-s390x/cpu-qom.h b/target-s390x/cpu-qom.h
>> index 34d45c2..3370fb9 100644
>> --- a/target-s390x/cpu-qom.h
>> +++ b/target-s390x/cpu-qom.h
>> @@ -73,4 +73,25 @@ static inline S390CPU *s390_env_get_cpu(CPUS390XState *env)
>>
>> void s390_cpu_do_interrupt(CPUState *cpu);
>>
>> +int s390_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cpu,
>> +        int cpuid, void *opaque);
>> +
>> +static inline int s390_cpu_write_elf64_qemunote(WriteCoreDumpFunction f,
>> +        CPUState *env, void *opaque)
>> +{
>> +    return 0;
>> +}
>> +
>> +static inline int s390_cpu_write_elf32_qemunote(WriteCoreDumpFunction f,
>> +        CPUState *env, void *opaque)
>> +{
>> +    return 0;
>> +}
>> +
>> +static inline int s390_cpu_write_elf32_note(WriteCoreDumpFunction f,
>> +        CPUState *env, int cpuid, void *opaque)
>> +{
>> +    return 0;
>> +}
>> +
>> #endif
>> diff --git a/target-s390x/cpu.c b/target-s390x/cpu.c
>> index 23fe51f..27cfbc0 100644
>> --- a/target-s390x/cpu.c
>> +++ b/target-s390x/cpu.c
>> @@ -27,6 +27,7 @@
>> #include "qemu-common.h"
>> #include "qemu/timer.h"
>> #include "hw/hw.h"
>> +#include "cpu-qom.h"
>> #ifndef CONFIG_USER_ONLY
>> #include "sysemu/arch_init.h"
>> #endif
>> @@ -168,6 +169,12 @@ static void s390_cpu_class_init(ObjectClass *oc, void *data)
>>
>>      scc->parent_reset = cc->reset;
>>      cc->reset = s390_cpu_reset;
>> +#if !defined(CONFIG_USER_ONLY)
>> +    cc->write_elf64_note = s390_cpu_write_elf64_note;
>> +    cc->write_elf64_qemunote = s390_cpu_write_elf64_qemunote;
>> +    cc->write_elf32_note = s390_cpu_write_elf32_note;
>> +    cc->write_elf32_qemunote = s390_cpu_write_elf32_qemunote;
>> +#endif
>>
>>      cc->do_interrupt = s390_cpu_do_interrupt;
>>      dc->vmsd = &vmstate_s390_cpu;
>> -- 
>> 1.7.12.4
>>