Re: [Qemu-devel] [PATCH qemu v2] target-ppc: Define get_monitor_def

[David Gibson <david@gibson.dropbear.id.au>]

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On Fri, Aug 14, 2015 at 01:52:18AM +1000, Alexey Kardashevskiy wrote:
> At the moment get_monitor_def() prints only registers from monitor_defs.
> However there is a lot of BOOK3S SPRs which are not in the list and
> cannot be printed.
> 
> This makes use of the new get_monitor_def() callback and prints all
> registered SPRs and fails on unregistered ones proving the user
> information on what is actually supported in the running CPU.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
> Changes:
> v2:
> * handles r**, f**, sr** if their numbers  were parsed completely and correctly
> * added "cr" as synonym of "ccr"

[snip]
> +static bool ppc_cpu_get_reg(target_ulong *regs, const char *numstr, int maxnum,
> +                            uint64_t *pval)
> +{
> +    char *endptr = NULL;
> +    int regnum = strtoul(numstr, &endptr, 10);
> +
> +    if ((endptr && *endptr) || (regnum >= maxnum)) {

Sorry I didn't pick this up in v1, but I think these conditiojns
aren't quite right.  *endptr is ok (fail if there were invalid
characters).  But AFAICT from strtoul(3), endptr will *always* be
non-NULL (somewhere between numstr and the end of the string).  You
also need to check if *numstr == '\0' to catch the case of no number
at all.

> +        return false;
> +    }
> +    *pval = regs[regnum];
> +
> +    return true;
> +}
> +
> +int ppc_cpu_get_monitor_def(CPUState *cs, const char *name, uint64_t *pval)
> +{
> +    int i;
> +    PowerPCCPU *cpu = POWERPC_CPU(cs);
> +    CPUPPCState *env = &cpu->env;
> +
> +#define MONREG(s, f) \
> +    if ((strcasecmp((s), name) == 0)) { \
> +        *pval = (f); \
> +        return 0; \
> +    }
> +    MONREG("pc", env->nip)
> +    MONREG("nip", env->nip)
> +    MONREG("lr", env->lr)
> +    MONREG("ctr", env->ctr)
> +    MONREG("xer", env->xer)
> +    MONREG("decr", cpu_ppc_load_decr(env))
> +    MONREG("msr",  env->msr)
> +    MONREG("tbu",  cpu_ppc_load_tbu(env))
> +    MONREG("tbl", cpu_ppc_load_tbl(env))
> +
> +    if ((strcasecmp("ccr", name) == 0) || (strcasecmp("cr", name) == 0)) {
> +        unsigned int u = 0;
> +
> +        for (i = 0; i < 8; i++)
> +            u |= env->crf[i] << (32 - (4 * (i + 1)));
> +
> +        return u;
> +    }
> +
> +    /* General purpose registers */
> +    if ((name[0] == 'r') &&

These cases will catch "r3" but not "R3", whereas for sprs it will
handle any case.

> +        ppc_cpu_get_reg(env->gpr, name + 1, ARRAY_SIZE(env->gpr), pval)) {
> +        return 0;
> +    }
> +
> +    /* Floating point registers */
> +    if ((name[0] == 'f') &&
> +        ppc_cpu_get_reg(env->fpr, name + 1, ARRAY_SIZE(env->fpr), pval)) {
> +        return 0;
> +    }
> +
> +    /* Segment registers */
> +    if ((strncmp(name, "sr", 2) == 0) &&
> +        ppc_cpu_get_reg(env->sr, name + 2, ARRAY_SIZE(env->sr), pval)) {
> +        return 0;
> +    }
> +
> +    /* Special purpose registers */
> +    for (i = 0; i < ARRAY_SIZE(env->spr_cb); ++i) {
> +        ppc_spr_t *spr = &env->spr_cb[i];
> +
> +        if (spr->name && (strcasecmp(name, spr->name) == 0)) {
> +            *pval = env->spr[i];
> +            return 0;
> +        }
> +    }
> +
> +    return -EINVAL;
> +}
> +
>  /*****************************************************************************/
>  static inline void gen_intermediate_code_internal(PowerPCCPU *cpu,
>                                                    TranslationBlock *tb,
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index 16d7b16..038674a 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -9706,6 +9706,7 @@ static void ppc_cpu_class_init(ObjectClass *oc, void *data)
>      cc->cpu_exec_interrupt = ppc_cpu_exec_interrupt;
>      cc->dump_state = ppc_cpu_dump_state;
>      cc->dump_statistics = ppc_cpu_dump_statistics;
> +    cc->get_monitor_def = ppc_cpu_get_monitor_def;
>      cc->set_pc = ppc_cpu_set_pc;
>      cc->gdb_read_register = ppc_cpu_gdb_read_register;
>      cc->gdb_write_register = ppc_cpu_gdb_write_register;

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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