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

[Alexander Graf]

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 <address@hidden>
> Signed-off-by: Jens Freimann <address@hidden>
> ---
> 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 <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]);

be32? Please verify whether you produce proper dumps on a little endian host.


Alex

> +    }
> +
> +    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
>