Re: [PATCH 6/9] pci-assign: Proper initialization for MSI-X table

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jan 31, 2012 at 08:16:31PM +0100, Jan Kiszka wrote:
> On 2012-01-31 20:12, Michael S. Tsirkin wrote:
> > On Tue, Jan 31, 2012 at 12:07:39PM -0700, Alex Williamson wrote:
> >> On Tue, 2012-01-31 at 19:40 +0200, Michael S. Tsirkin wrote:
> >>> On Sat, Jan 28, 2012 at 07:22:09AM -0700, Alex Williamson wrote:
> >>>> Per the PCI spec, all vectors should be masked at handoff.
> >>>>
> >>>> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> >>>> ---
> >>>>
> >>>>  hw/device-assignment.c |   20 +++++++++++++++++++-
> >>>>  1 files changed, 19 insertions(+), 1 deletions(-)
> >>>>
> >>>> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> >>>> index af614d3..6efa219 100644
> >>>> --- a/hw/device-assignment.c
> >>>> +++ b/hw/device-assignment.c
> >>>> @@ -1462,6 +1462,22 @@ static const MemoryRegionOps msix_mmio_ops = {
> >>>>      },
> >>>>  };
> >>>>  
> >>>> +static void msix_reset(AssignedDevice *dev)
> >>>> +{
> >>>> +    MSIXTableEntry *entry;
> >>>> +    int i;
> >>>> +
> >>>> +    if (!dev->msix_table) {
> >>>> +        return;
> >>>> +    }
> >>>> +
> >>>> +    memset(dev->msix_table, 0, 0x1000);
> >>>> +
> >>>> +    for (i = 0, entry = dev->msix_table; i < dev->msix_max; i++, entry++) {
> >>>> +        entry->ctrl = 0x1; /* Masked */
> >>>
> >>> This is broken for BE hosts.
> >>
> >> Show me a BE host that even remotely works with this device assignment
> >> implementation.  Thanks,
> >>
> >> Alex
> > 
> > I don't get it. Yes lots of cleanup is needed but why add more broken
> > code?
> 
> At some point, we will just do this via the PCI core, and that will have
> to do it correctly anyway. This code here is supposed to be removed again.
> 
> Jan

Either we say this is all dead code, then
let's just fix bugs until it is rewritten.
To fix the bug, all we need is patch 9, maybe 6 and 7.

Or there is intent to maintain it going forward
then, methinks, it needs to be brought up to
some minimal standards.


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