Re: [PATCH v1 06/13] plugins: add API to return a name for a IO device

["Alex Bennée" <alex.bennee@linaro.org>]

Philippe Mathieu-Daudé <f4bug@amsat.org> writes:

> On 7/9/20 4:13 PM, Alex Bennée wrote:
>> This may well end up being anonymous but it should always be unique.
>> 
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> [r-b provisional given change to g_intern_string]
>> Reviewed-by: Clement Deschamps <clement.deschamps@greensocs.com>
>> Reviewed-by: Emilio G. Cota <cota@braap.org>
>> 
>> ---
>> v3
>>   - return a non-freeable const g_intern_string()
>>   - checkpatch cleanups
>> ---
>>  include/qemu/qemu-plugin.h |  6 ++++++
>>  plugins/api.c              | 20 ++++++++++++++++++++
>>  2 files changed, 26 insertions(+)
>> 
>> diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
>> index bab8b0d4b3af..c98c18d6b052 100644
>> --- a/include/qemu/qemu-plugin.h
>> +++ b/include/qemu/qemu-plugin.h
>> @@ -335,6 +335,12 @@ struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
>>  bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr);
>>  uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr);
>>  
>> +/*
>> + * Returns a string representing the device. The string is valid for
>> + * the lifetime of the plugin.
>> + */
>> +const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h);
>> +
>>  typedef void
>>  (*qemu_plugin_vcpu_mem_cb_t)(unsigned int vcpu_index,
>>                               qemu_plugin_meminfo_t info, uint64_t vaddr,
>> diff --git a/plugins/api.c b/plugins/api.c
>> index bbdc5a4eb46d..4304e63f0cf8 100644
>> --- a/plugins/api.c
>> +++ b/plugins/api.c
>> @@ -303,6 +303,26 @@ uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr
>>      return 0;
>>  }
>>  
>> +const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
>> +{
>> +#ifdef CONFIG_SOFTMMU
>> +    if (h && h->is_io) {
>> +        MemoryRegionSection *mrs = h->v.io.section;
>> +        if (!mrs->mr->name) {
>> +            unsigned long maddr = 0xffffffff & (uintptr_t) mrs->mr;
>
> Why not use uint32_t & PRIx32?
>
>                uint32_t maddr = (uintptr_t) mrs->mr;
>
>> +            g_autofree char *temp = g_strdup_printf("anon%08lx", maddr);
>> +            return g_intern_string(temp);
>
> Isn't this illegal? temp is definitively not const...

We don't mess with it, we return a new string which is the canonical
form.

>
>> +        } else {
>> +            return g_intern_string(mrs->mr->name);
>> +        }
>> +    } else {
>> +        return g_intern_string("RAM");
>> +    }
>> +#else
>> +    return g_intern_string("Invalid");
>> +#endif
>> +}
>> +
>>  /*
>>   * Queries to the number and potential maximum number of vCPUs there
>>   * will be. This helps the plugin dimension per-vcpu arrays.
>> 


-- 
Alex Bennée