Re: [Xen-devel] [v8][PATCH 06/16] hvmloader/pci: disable all pci devices conflicting with rdm

["Chen, Tiejun" <tiejun.chen@xxxxxxxxx>]

> > What about this?
> Looks reasonable (but don't forget that I continue to be unconvinced
> that the patch as a whole makes sense).
Yes, I always keep this in my mind as I mentioned in patch #00. Any risk 
you're still concerning? Is it that case if guest OS force enabling 
these devices again? IMO, at this point there are two cases:
#1. Without passing through a RMRR device

Those emulated devices don't create 1:1 mapping so its safe, right?

#2. With passing through a RMRR device

This just probably cause these associated devices not to work well, but 
still don't bring any impact to other Domains, right? I mean this isn't 
going to worsen the preexisting situation.
If I'm wrong please correct me.

Thanks
Tiejun

> Jan
>
> > +    bool is_conflict = false;
> >
> >        for ( devfn = 0; devfn < 256; devfn++ )
> >        {
> > @@ -60,7 +61,7 @@ static void disable_conflicting_devices(void)
> >                continue;
> >
> >            /* Check all bars */
> > -        for ( bar = 0; bar < 7; bar++ )
> > +        for ( bar = 0; bar < 7 && !is_conflict; bar++ )
> >            {
> >                bar_reg = PCI_BASE_ADDRESS_0 + 4*bar;
> >                if ( bar == 6 )
> > @@ -89,7 +90,7 @@ static void disable_conflicting_devices(void)
> >                bar_sz = pci_readl(devfn, bar_reg);
> >                bar_sz &= PCI_BASE_ADDRESS_MEM_MASK;
> >
> > -            for ( i = 0; i < memory_map.nr_map ; i++ )
> > +            for ( i = 0; i < memory_map.nr_map && !is_conflict; i++ )
> >                {
> >                    if ( memory_map.map[i].type == E820_RESERVED )
> >                    {
> > @@ -105,13 +106,13 @@ static void disable_conflicting_devices(void)
> >                                   devfn>>3, devfn&7, bar_reg, bar_data);
> >                            cmd = pci_readw(devfn, PCI_COMMAND);
> >                            pci_writew(devfn, PCI_COMMAND, ~cmd);
> > -                        /* Jump next device. */
> > -                        goto check_next_device;
> > +                        /* So need to jump next device. */
> > +                        is_conflict = true;
> >                        }
> >                    }
> >                }
> >            }
> > - check_next_device:
> > +        is_conflict = false;
> >        }
> >    }
> >
> > Thanks
> > Tiejun
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel