Re: [PATCH] sun4u: remap ebus BAR0 to use unassigned_io_ops instead of alias to PCI IO space

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 11/3/24 09:28, Philippe Mathieu-Daudé wrote:
> On 11/3/24 07:43, Mark Cave-Ayland wrote:
>> During kernel startup OpenBSD accesses addresses mapped by BAR0 of the 
>> ebus device
>> but at offsets where no IO devices exist. Before commit 4aa07e8649 
>> ("hw/sparc64/ebus:
>> Access memory regions via pci_address_space_io()") BAR0 was mapped to 
>> legacy IO
>> space which allows accesses to unmapped devices to succeed, but 
>> afterwards these
>> accesses to unmapped PCI IO space cause a memory fault which prevents 
>> OpenBSD from
>> booting.
>>
>> Since no devices are mapped at the addresses accessed by OpenBSD, 
>> change ebus BAR0
>> from a PCI IO space alias to an IO memory region using 
>> unassigned_io_ops which allows
>> these accesses to succeed and so allows OpenBSD to boot once again.
>>
>> Fixes: 4aa07e8649 ("hw/sparc64/ebus: Access memory regions via 
>> pci_address_space_io()")
>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> 
>> ---
>>
>> [MCA: I'd like to merge this for 9.0 since I've been carrying various 
>> local workarounds
>> to allow OpenBSD to boot on SPARC64 for some time.]
> 
> Sure.

Patch queued!