Re: [kvm-unit-tests PATCH v4 2/3] s390x: define UV compatible I/O allocation

[Pierre Morel <pmorel@linux.ibm.com>]

On 1/21/21 10:46 AM, Janosch Frank wrote:
> On 1/21/21 10:13 AM, Pierre Morel wrote:
>> To centralize the memory allocation for I/O we define
>> the alloc_io_page/free_io_page functions which share the I/O
>> memory with the host in case the guest runs with
>> protected virtualization.
>>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   MAINTAINERS           |  1 +
>>   lib/s390x/malloc_io.c | 70 +++++++++++++++++++++++++++++++++++++++++++
>>   lib/s390x/malloc_io.h | 45 ++++++++++++++++++++++++++++
>>   s390x/Makefile        |  1 +
>>   4 files changed, 117 insertions(+)
>>   create mode 100644 lib/s390x/malloc_io.c
>>   create mode 100644 lib/s390x/malloc_io.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 54124f6..89cb01e 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -82,6 +82,7 @@ M: Thomas Huth <thuth@redhat.com>
>>   M: David Hildenbrand <david@redhat.com>
>>   M: Janosch Frank <frankja@linux.ibm.com>
>>   R: Cornelia Huck <cohuck@redhat.com>
>> +R: Pierre Morel <pmorel@linux.ibm.com>
> 
> If you're ok with the amount of mails you'll get then go ahead.
> But I think maintainer file changes should always be in a separate patch.

You are right it was more an attempts to bring the Linux checkpatch to 
be quiet but this would need more changes so.. we can discuss this in a 
separate patch.

> 
>>   L: kvm@vger.kernel.org
>>   L: linux-s390@vger.kernel.org
>>   F: s390x/*
>> diff --git a/lib/s390x/malloc_io.c b/lib/s390x/malloc_io.c
>> new file mode 100644
>> index 0000000..bfe8c6a
>> --- /dev/null
>> +++ b/lib/s390x/malloc_io.c
>> @@ -0,0 +1,70 @@
>> +// SPDX-License-Identifier: GPL-2.0
> 
> I think we wanted to use:
> /* SPDX-License-Identifier: GPL-2.0-or-later */

yes


...snip...
>> +
>> +void free_io_pages(void *p, int size)
>> +{
>> +	int order = size >> PAGE_SHIFT;
>> +
>> +	assert(IS_ALIGNED((uintptr_t)p, PAGE_SIZE));
>> +
>> +	if (test_facility(158))
>> +		unshare_pages(p, 1 << order);
> 
> I have a lib file in the making that will let you check UV features like
> test_facility(). When that's ready I'm gonna check for unshare here.

OK

Thanks,
Pierre

-- 
Pierre Morel
IBM Lab Boeblingen