Re: [PATCH v6 08/12] hw/cxl/cxl-mailbox-utils: Add mailbox commands to support add/release dynamic capacity response

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

On Thu, 4 Apr 2024 13:32:23 +0000
Jørgen Hansen <Jorgen.Hansen@wdc.com> wrote:

Hi Jørgen,

> > +static CXLRetCode cmd_dcd_add_dyn_cap_rsp(const struct cxl_cmd *cmd,
> > +                                          uint8_t *payload_in,
> > +                                          size_t len_in,
> > +                                          uint8_t *payload_out,
> > +                                          size_t *len_out,
> > +                                          CXLCCI *cci)
> > +{
> > +    CXLUpdateDCExtentListInPl *in = (void *)payload_in;
> > +    CXLType3Dev *ct3d = CXL_TYPE3(cci->d);
> > +    CXLDCExtentList *extent_list = &ct3d->dc.extents;
> > +    uint32_t i;
> > +    uint64_t dpa, len;
> > +    CXLRetCode ret;
> > +
> > +    if (in->num_entries_updated == 0) {
> > +        return CXL_MBOX_SUCCESS;
> > +    }  
> 
> The mailbox processing in patch 2 converts from le explicitly, whereas 
> the mailbox commands here don't. Looking at the existing mailbox 
> commands, convertion doesn't seem to be rigorously applied, so maybe 
> that is OK?

The early CXL code didn't take this into account much at all. We've
sort of been fixing stuff up as we happen to be working on it. Hence
some stuff is big endian safe and some not :(

Patches welcome, but it would be good to not introduce more cases
that need fixing when we eventually clean them all up (and have
a big endian test platform to see if we got it right!)

Jonathan