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

[Michael S. Tsirkin]

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?

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;