Re: [PATCH v8 4/5] hw/mem/cxl-type3: Add CXL CDAT Data Object Exchange

[Jonathan Cameron via <qemu-devel@nongnu.org>]

On Thu, 13 Oct 2022 13:09:26 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Thu, Oct 13, 2022 at 12:26:58PM -0400, Gregory Price wrote:
> > Other than the nitpicks below, lgtm.  Not sure if you need a sign off
> > from me given the contributions:
> > 
> > Signed-off-by: Gregory Price <gregory.price@memverge.com>
> >   
> > > +/* If no cdat_table == NULL returns number of entries */
> > > +static int ct3_build_cdat_entries_for_mr(CDATSubHeader **cdat_table,
> > > +                                         int dsmad_handle, MemoryRegion *mr)
> > > +{
> > > +    enum {
> > > +        DSMAS,
> > > +        DSLBIS0,
> > > +        DSLBIS1,
> > > +        DSLBIS2,
> > > +        DSLBIS3,
> > > +        DSEMTS,
> > > +        NUM_ENTRIES
> > > +    };  
> > // ...  
> > > +    if (!cdat_table) {
> > > +        return NUM_ENTRIES;
> > > +    }  
> > 
> > the only thing that i would recommend is making this enum global (maybe
> > renaming them CT3_CDAT_[ENTRY_NAME]) and using CT3_CDAT_NUM_ENTRIES
> > directly in the function that allocates the cdat buffer itself.  
> 
> 
> Yes I think I agree here.

Ok, seems a consensus against having this local.

I can do this for now and then revisit if / when things become more complex
and this becomes not global.  I guess a potential case of premature flexibility.

Jonathan

> 
> > I do
> > understand the want to keep the enum and the code creating the entries
> > co-located though, so i'm just nitpicking here i guess.
> > 
> > Generally I dislike the pattern of passing a NULL into a function to get
> > configuration data, and then calling that function again.  This function
> > wants to be named...
> > 
> > ct3_build_cdat_entries_for_mr_or_get_table_size_if_cdat_is_null(...)
> > 
> > to accurately describe what it does.  Just kinda feels like an extra
> > function call for no reason.
> > 
> > But either way, it works, this is just a nitpick on my side.
> >   
> > > +static int ct3_build_cdat_table(CDATSubHeader ***cdat_table, void *priv)
> > > +{
> > > +    g_autofree CDATSubHeader **table = NULL;
> > > +    CXLType3Dev *ct3d = priv;
> > > +    MemoryRegion *volatile_mr;
> > > +    /* ... snip ... */
> > > +}  
> > 
> > s/volatile/nonvolatile  
>