Re: [Qemu-devel] [PATCH v1 0/5][RFC] Refactoring of AIS support

[Christian Borntraeger]

On 10/30/2017 05:59 PM, Cornelia Huck wrote:
> On Mon, 30 Oct 2017 14:48:23 +0100
> Christian Borntraeger <address@hidden> wrote:
> 
> 
>> FWIW, I am testing a guest patch that enables zPCI without AIS. Its as 
>> simple as
>>
>>
>> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
>> index 7b30af5..9b24836 100644
>> --- a/arch/s390/pci/pci.c
>> +++ b/arch/s390/pci/pci.c
>> @@ -953,7 +953,7 @@ static int __init pci_base_init(void)
>>         if (!s390_pci_probe)
>>                 return 0;
>>  
>> -       if (!test_facility(69) || !test_facility(71) || !test_facility(72))
>> +       if (!test_facility(69) || !test_facility(71))
>>                 return 0;
>>  
>>         rc = zpci_debug_init();
>> diff --git a/arch/s390/pci/pci_insn.c b/arch/s390/pci/pci_insn.c
>> index ea34086..61f8c82 100644
>> --- a/arch/s390/pci/pci_insn.c
>> +++ b/arch/s390/pci/pci_insn.c
>> @@ -7,6 +7,7 @@
>>  #include <linux/export.h>
>>  #include <linux/errno.h>
>>  #include <linux/delay.h>
>> +#include <asm/facility.h>
>>  #include <asm/pci_insn.h>
>>  #include <asm/pci_debug.h>
>>  #include <asm/processor.h>
>> @@ -93,6 +94,8 @@ int zpci_refresh_trans(u64 fn, u64 addr, u64 range)
>>  /* Set Interruption Controls */
>>  void zpci_set_irq_ctrl(u16 ctl, char *unused, u8 isc)
>>  {
>> +       if (!test_facility(72))
>> +               return;
>>         asm volatile (
>>                 "       .insn   rsy,0xeb00000000d1,%[ctl],%[isc],%[u]\n"
>>                 : : [ctl] "d" (ctl), [isc] "d" (isc << 27), [u] "Q" 
>> (*unused));
>>
> 
> Sounds good. Presumably this makes the adapter interrupt handling work
> as for virtio (and qdio)? Is there any ais-less pci hardware out in the
> wild?
> 

ais is z specific, not PCI specific. So PCI cards should not care as far as I 
can tell.