Re: [kvm-unit-tests PATCH v2 6/8] s390x: css: testing ssch error response

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

On 3/26/21 11:58 AM, Claudio Imbrenda wrote:
> On Fri, 26 Mar 2021 11:41:34 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> On 3/25/21 5:02 PM, Claudio Imbrenda wrote:
>>> On Thu, 25 Mar 2021 10:39:05 +0100
>>> Pierre Morel <pmorel@linux.ibm.com> wrote:
>>>    
>>
>> ...snip...
>>
>>
>> Trying to follow your comment, I have some questions:
>>
>>
>>>> +	/* 2- ORB address should be lower than 2G */
>>>> +	report_prefix_push("ORB Address above 2G");
>>>> +	expect_pgm_int();
>>>> +	ssch(test_device_sid, (void *)0x80000000);
>>>
>>> another hardcoded address... you should try allocating memory over
>>> 2G, and try to use it. put a check if there is enough memory, and
>>> skip if you do not have enough memory, like you did below
>>
>> How can I allocate memory above 2G?
> 
> alloc_pages_flags(order, AREA_NORMAL)
> 
> btw that allocation will fail if there is no free memory available
> above 2G
> 
>>>    
>>>> +	check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
>>>> +	report_prefix_pop();
>>>> +
>>>> +	/* 3- ORB address should be available we check 1G*/
>>>> +	top = get_ram_size();
>>>> +	report_prefix_push("ORB Address must be available");
>>>> +	if (top < 0x40000000) {
>>>> +		expect_pgm_int();
>>>> +		ssch(test_device_sid, (void *)0x40000000);
>>>> +		check_pgm_int_code(PGM_INT_CODE_ADDRESSING);
>>>> +	} else {
>>>> +		report_skip("guest started with more than 1G
>>>> memory");
>>>
>>> this is what I meant above. you will need to run this test both
>>> with 1G and with 3G of ram (look at the SCLP test, it has the same
>>> issue)
>>
>> I do not understand, if I test with 3G RAM, I suppose that the
>> framework works right and I have my 3G RAM available.
>> Then I can check with an address under 1G and recheck with an address
>> above 1G.
>>
>> What is the purpose to check with only 1G memory?
> 
> you need to run this test twice, once with 1G and once with 3G.
> it's the same test, so it can't know if it is being run with 1G or
> 3G, so you have to test for it.
> 
> when you need a valid address above 2G, you need to make sure you have
> that much memory, and when you want an invalid address between 1G and
> 2G, you have to make sure you have no more than 1G.

OK, thanks




-- 
Pierre Morel
IBM Lab Boeblingen