Re: [Qemu-devel] [PATCH] pci: remove explicit check to 64K ioport size

[Hervé Poussineau]

Michael S. Tsirkin a écrit :
> On Fri, Sep 13, 2013 at 01:58:44PM +0200, Hervé Poussineau wrote:
> > This check is useless, as bigger addresses will be ignored when
> > added to 'io' MemoryRegion, which has a size of 64K.
> >
> > However, some architectures don't use the 'io' MemoryRegion, like
> > the alpha and versatile platforms. They create a PCI I/O region
> > bigger than 64K, so let them handle PCI I/O BARs in the higher range.
> >
> > Signed-off-by: Hervé Poussineau <address@hidden>
> > ---
> >  hw/pci/pci.c |    3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> > index d00682e..a8e2b29 100644
> > --- a/hw/pci/pci.c
> > +++ b/hw/pci/pci.c
> > @@ -1028,8 +1028,7 @@ static pcibus_t pci_bar_address(PCIDevice *d,
> >          }
> >          new_addr = pci_get_long(d->config + bar) & ~(size - 1);
> >          last_addr = new_addr + size - 1;
> > -        /* NOTE: we have only 64K ioports on PC */
> > -        if (last_addr <= new_addr || new_addr == 0 || last_addr > UINT16_MAX) {
> > +        if (last_addr <= new_addr || new_addr == 0) {
> >              return PCI_BAR_UNMAPPED;
> >          }
> >          return new_addr;
> > --
> > 1.7.10.4
>
> We still didn't fix the overlap for PCI BARs properly
> so it looks like the following is needed on top.
> Could you please check whether this works for you on versatile/alpha?

Yes, alpha and versatile still seem to work.

Hervé

> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index d452135..3118854 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -1028,7 +1028,10 @@ static pcibus_t pci_bar_address(PCIDevice *d,
>          }
>          new_addr = pci_get_long(d->config + bar) & ~(size - 1);
>          last_addr = new_addr + size - 1;
> -        if (last_addr <= new_addr || new_addr == 0) {
> +        /* Check if BAR is being sized explicitly.
> +         * TODO: make priorities correct and remove this work around.
> +         */
> +        if (last_addr <= new_addr || new_addr == 0 || last_addr >= UINT32_MAX) 
> {
>              return PCI_BAR_UNMAPPED;
>          }
>          return new_addr;