Re: [Qemu-devel] [PATCH v3 11/13] tests: acpi: add simple arm/virt testcase

[Wei Xu]

Hi Igor,

On 5/2/2019 3:24 PM, Igor Mammedov wrote:
> On Fri, 26 Apr 2019 17:28:10 +0100
> Wei Xu <address@hidden> wrote:
> 
>> Hi Igor,
>>
>> On 4/26/2019 12:54 PM, Igor Mammedov wrote:
>>> On Fri, 26 Apr 2019 00:51:56 +0800
>>> x00249684 <address@hidden> wrote:
>>>
>>>> Hi Igor,
>>>>
>>>> +static void test_acpi_virt_tcg(void)
>>>> +{
>>>> +    test_data data = {
>>>> +        .machine = "virt",
>>>> +        .uefi_fl1 = "pc-bios/edk2-aarch64-code.fd",
>>>> +        .uefi_fl2 = "pc-bios/edk2-arm-vars.fd",
>>>> +        .cd = 
>>>> "tests/data/uefi-boot-images/bios-tables-test.aarch64.iso.qcow2",
>>>> +        .ram_start = 0x40000000ULL,
>>>> +        .scan_len = 128ULL * 1024 * 1024,
>>>> +    };
>>>> +
>>>> +    test_acpi_one("-cpu cortex-a57 ", &data);
>>>>
>>>> Replaced the cortex-a57 with host and succesfully tested on the hisilicon 
>>>> arm64 
>>>> D05 board. Otherwise it failed with "kvm_init_vcpu failed: Invalid 
>>>> argument".
>>>> Is it possilbe to set the cpu type like numa-test.c?
>>>
>>> I think it works with numa-test because it uses TCG only but in case of 
>>> bios-tables-test
>>> it uses accel="kvm:tcg" to leverage KVM capabilities whenever possible to 
>>> speed up test.
>>>
>>> Now back to our ARM test case, uefi requirement is to use 64bit CPU (hence 
>>> it was cortex-a57)
>>> however unlike x86 it obviously breaks since KVM accelerator on ARM host is 
>>> used
>>> and it doesn't work with anything other than 'host' cpu model.
>>>
>>> I think we still want to use KVM whenever possible, but problem lies in that
>>> user (testcase) doesn't have an idea if KVM accelerator is available and 
>>> host is 64 CPU.
>>>
>>> to sum up we need to support 2 modes:
>>>   1. host is 64 ARM, use kvm with -cpu host
>>>   2. all other cases use tcg with -cpu cortex-a57
>>>
>>> I can hack to probe if /dev/kvm is accessible and host is 64 bit and use #1
>>> otherwise fallback to #2
>>> or as quick fix do only #2 initially and think about a better solution to 
>>> #1 
>>
>> Thanks!
>> Fine to me.
>>
>>>
>>> Is there any other suggestions/opinions how to approach issue/proceed.
>>
>> To check the host cpu architecture is ARM or not, maybe we can check the 
>> value
>> of "CPU implementer" is 0x41 or not from the /proc/cpuinfo.
> 
> it turned out it's more complicated.
> we also should pick a correct GIC depending on host's CPU and that
> changes ACPI tables, so it will worn on some hosts and fail on other.
Sorry, I did not consider that case.

> 
> I'll add a patch to enable test case to pick accelerator and force TCG
> for ARM tests for now.
>

Thanks!

Best Regards,
Wei

>>
>> Best Regards,
>> Wei
>>
>>>
>>> PS:
>>> we probably would like to reuse this not only for acpi tests but also for 
>>> other
>>> arm/virt test cases that involve running guest code. 
>>>
>>>> Thanks!
>>>>
>>>> Best Regards,
>>>> Wei
>>>
>>>
>>> .
>>>
>>
> 
> 
> .
>