Re: [Qemu-devel] [PATCH V7 23/24] apci: fix PXB behaviour if used with unsupported BIOS

[Marcel Apfelbaum <marcel@redhat.com>]

On 05/31/2015 09:12 PM, Michael S. Tsirkin wrote:
> On Mon, May 25, 2015 at 06:34:01PM +0300, Marcel Apfelbaum wrote:
>> PXB does not work with unsupported bioses, but should
>> not interfere with normal OS operation.
>> We don't ship them anymore, but it's reasonable
>> to keep the work-around until we update the bios in qemu.
>
> We already did, did we not?
Yes, we did, but Gerd preferred to keep this patch around.
Adding him to thread.

CC: Gerd Hoffmann <kraxel@redhat.com>

Thanks,
Marcel

>
>> Fix this by not adding PXB mem/IO chunks to _CRS
>> if they weren't configured by BIOS.
>>
>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>> ---
>>   hw/i386/acpi-build.c | 87 ++++++++++++++++++++++++++++++++++------------------
>>   1 file changed, 58 insertions(+), 29 deletions(-)
>>
>> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
>> index f7d2c80..895d64c 100644
>> --- a/hw/i386/acpi-build.c
>> +++ b/hw/i386/acpi-build.c
>> @@ -784,6 +784,14 @@ static Aml *build_crs(PCIHostState *host,
>>               range_base = r->addr;
>>               range_limit = r->addr + r->size - 1;
>>
>> +            /*
>> +             * Work-around for old bioses
>> +             * that do not support multiple root buses
>> +             */
>> +            if (!range_base || range_base > range_limit) {
>> +                continue;
>> +            }
>> +
>>               if (r->type & PCI_BASE_ADDRESS_SPACE_IO) {
>>                   aml_append(crs,
>>                       aml_word_io(aml_min_fixed, aml_max_fixed,
>> @@ -817,45 +825,66 @@ static Aml *build_crs(PCIHostState *host,
>>
>>               range_base = pci_bridge_get_base(dev, PCI_BASE_ADDRESS_SPACE_IO);
>>               range_limit = pci_bridge_get_limit(dev, PCI_BASE_ADDRESS_SPACE_IO);
>> -            aml_append(crs,
>> -                aml_word_io(aml_min_fixed, aml_max_fixed,
>> -                            aml_pos_decode, aml_entire_range,
>> -                            0,
>> -                            range_base,
>> -                            range_limit,
>> -                            0,
>> -                            range_limit - range_base + 1));
>> -            crs_range_insert(io_ranges, range_base, range_limit);
>> +
>> +            /*
>> +             * Work-around for old bioses
>> +             * that do not support multiple root buses
>> +             */
>> +            if (range_base || range_base > range_limit) {
>> +                aml_append(crs,
>> +                           aml_word_io(aml_min_fixed, aml_max_fixed,
>> +                                       aml_pos_decode, aml_entire_range,
>> +                                       0,
>> +                                       range_base,
>> +                                       range_limit,
>> +                                       0,
>> +                                       range_limit - range_base + 1));
>> +                crs_range_insert(io_ranges, range_base, range_limit);
>> +            }
>>
>>               range_base =
>>                   pci_bridge_get_base(dev, PCI_BASE_ADDRESS_SPACE_MEMORY);
>>               range_limit =
>>                   pci_bridge_get_limit(dev, PCI_BASE_ADDRESS_SPACE_MEMORY);
>> -            aml_append(crs,
>> -                aml_dword_memory(aml_pos_decode, aml_min_fixed,
>> -                                 aml_max_fixed, aml_non_cacheable,
>> -                                 aml_ReadWrite,
>> -                                 0,
>> -                                 range_base,
>> -                                 range_limit,
>> -                                 0,
>> -                                 range_limit - range_base + 1));
>> -            crs_range_insert(mem_ranges, range_base, range_limit);
>> +
>> +            /*
>> +             * Work-around for old bioses
>> +             * that do not support multiple root buses
>> +             */
>> +            if (range_base || range_base > range_limit) {
>> +                aml_append(crs,
>> +                           aml_dword_memory(aml_pos_decode, aml_min_fixed,
>> +                                            aml_max_fixed, aml_non_cacheable,
>> +                                            aml_ReadWrite,
>> +                                            0,
>> +                                            range_base,
>> +                                            range_limit,
>> +                                            0,
>> +                                            range_limit - range_base + 1));
>> +                crs_range_insert(mem_ranges, range_base, range_limit);
>> +          }
>>
>>               range_base =
>>                   pci_bridge_get_base(dev, PCI_BASE_ADDRESS_MEM_PREFETCH);
>>               range_limit =
>>                   pci_bridge_get_limit(dev, PCI_BASE_ADDRESS_MEM_PREFETCH);
>> -            aml_append(crs,
>> -                aml_dword_memory(aml_pos_decode, aml_min_fixed,
>> -                                 aml_max_fixed, aml_non_cacheable,
>> -                                 aml_ReadWrite,
>> -                                 0,
>> -                                 range_base,
>> -                                 range_limit,
>> -                                 0,
>> -                                 range_limit - range_base + 1));
>> -            crs_range_insert(mem_ranges, range_base, range_limit);
>> +
>> +            /*
>> +             * Work-around for old bioses
>> +             * that do not support multiple root buses
>> +             */
>> +            if (range_base || range_base > range_limit) {
>> +                aml_append(crs,
>> +                           aml_dword_memory(aml_pos_decode, aml_min_fixed,
>> +                                            aml_max_fixed, aml_non_cacheable,
>> +                                            aml_ReadWrite,
>> +                                            0,
>> +                                            range_base,
>> +                                            range_limit,
>> +                                            0,
>> +                                            range_limit - range_base + 1));
>> +                crs_range_insert(mem_ranges, range_base, range_limit);
>> +            }
>>           }
>>       }
>>
>> --
>> 2.1.0
>>