Re: [PATCH 1/3] util: Introduce virAcpi module
On 4/6/23 11:20, Andrea Bolognani wrote:
On Thu, Apr 06, 2023 at 10:20:46AM +0200, Michal Prívozník wrote:
> On 4/5/23 19:21, Andrea Bolognani wrote:
>> On Wed, Apr 05, 2023 at 01:30:17PM +0200, Michal Privoznik wrote:
>>> + if (nodeHeader->len < sizeof(*nodeHeader)) {
>>> + virReportError(VIR_ERR_INTERNAL_ERROR,
>>> + _("IORT table node type %1$s has invalid length:
%2$" PRIu16),
>>
>> I'm not sure this plays well with the recently introduced changes to
>> translatable strings. Have you checked with Jirka?
>
> I haven't. But, gcc complains if only a part of string contains
> positioned arguments. That is:
>
> "argument value %1$s and another argument %s"
> "argument value %s and another argument %2$s"
>
> are invalid format string and compiler throws an error. Now, using no
> positions works:
>
> "argument value %s and another argument %s"
>
> but then, Jirka's syntax-check rule throws an error. But it doesn't for
> the case I'm using:
>
> "integer value %" PRIu16
Yeah, either your usage is fine or the syntax-check rule should be
improve to catch it. Jirka?
> Although, one could argue that if the translate tool doesn't allow fixed
> size integer types modifiers, then the tool is broken. Surely, libvirt's
> not the only one using fixed size integers. But okay, for error messages
> I can typecast arguments. IOW:
>
> virReportError(VIR_ERR_INTERNAL_ERROR,
> _("IORT table node type %1$s has invalid length: %2$u"),
> NULLSTR(typeStr), (unsigned int)nodeHeader->len);
This looks fine.
Perhaps a bit more useful:
virReportError(VIR_ERR_INTERNAL_ERROR,
_("IORT table node type %1$s has invalid length: got
%2$u, expected at least %3$lu"),
NULLSTR(typeStr), (unsigned int)nodeHeader->len,
sizeof(*nodeHeader));
>>> +typedef enum {
>>> + VIR_IORT_NODE_TYPE_UNKNOWN = -1,
>>
>> Do we need this? virIORTNodeHeader.type is defined as unsigned.
You didn't answer this one :)
That's because I removed it in v2 ;-)
>>> +typedef struct virIORTNodeHeader virIORTNodeHeader;
>>> +struct virIORTNodeHeader {
>>> + uint8_t type; /* One of virIORTNodeType */
>>> + uint16_t len;
>>> + uint8_t revision;
>>> + uint32_t identifier;
>>> + uint32_t nmappings;
>>> + uint32_t reference_id;
>>
>> Since we only care about type and length, we could simply not declare
>> the other four fields at all, right?
>
> Yes, except these fields are defined by the standard. We may need them
> in the future. Anyway - these are thrown right away anyway, if it's
> added memory consumption you're worried about.
> By the same token, we don't care about other types (root comples, PMCG,
> ITS group, ...) and yet we have them in the enum.
It's fine to keep them, I'm not too concerned about the memory usage,
I was just wondering how much we should push towards minimalism ;)
What about renaming @reference_id to @mappings_offset though, to
match the corresponding fields for nodes in virIORTHeader?
I can do that, but then again - it's named 'Reference to ID Array' in
the spec. And since I renamed SMMU_V1_2 to match whatever was in the
spec I figured staying close to the standard is key. Or how do we decide
when to stay true to the standard an when not?
If anything, it should be named reference_to_id_array. But I believe
that anybody who will extend this implementation will do the same as I
did - open the code and the spec next to each other and try to find a
match between tables in spec and structs in our code. At that point,
whether this field is named 'reference_id', 'mappings_offset' or
'reference_to_id_array' doesn't really matter.
Michal