Re: [PATCH] VT-d: avoid multi-message-MSI check for HPET

["Roger Pau Monné" <roger.pau@citrix.com>]

On Fri, Apr 10, 2026 at 07:51:45AM +0200, Jan Beulich wrote:
> On 09.04.2026 19:36, Roger Pau Monné wrote:
> > On Wed, Apr 01, 2026 at 02:47:48PM +0200, Jan Beulich wrote:
> >> Having this immediately below a PCI-dev vs HPET conditional is (mildly)
> >> confusing. Move that if() into the body of the earlier one.
> >>
> >> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> >>
> >> --- a/xen/drivers/passthrough/vtd/intremap.c
> >> +++ b/xen/drivers/passthrough/vtd/intremap.c
> >> @@ -513,13 +513,13 @@ static int msi_msg_to_remap_entry(
> >>  
> >>          if ( rc )
> >>              return rc;
> >> +
> >> +        if ( msi_desc->msi_attrib.type == PCI_CAP_ID_MSI )
> >> +            nr = msi_desc->msi.nvec;
> >>      }
> >>      else
> >>          set_hpet_source_id(msi_desc->hpet_id, &new_ire);
> >>  
> >> -    if ( msi_desc->msi_attrib.type == PCI_CAP_ID_MSI )
> >> -        nr = msi_desc->msi.nvec;
> >> -
> > 
> > I'm not fully opposed to this, but maybe it would be good to add a
> > small comment to note that HPET never use multi-vector MSI?
> 
> That aspect doesn't change - HPET code simply doesn't (and never should)
> set .type to PCI_CAP_ID_MSI. That field should reflect reality (and HPET,
> iirc, simply leaves it at 0).

Hm, I see, HPET is a very special case which have been "adjusted" to
fit the MSI generation logic.

Acked-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks, Roger.