Re: [PATCH v2] tools/kvm_stat: Fix kvm_exit filter name

[Gavin Shan <gshan@redhat.com>]

On 12/18/19 7:45 PM, Andrew Jones wrote:
> On Tue, Dec 17, 2019 at 01:06:00PM +1100, Gavin Shan wrote:
>> The filter name is fixed to "exit_reason" for some kvm_exit events, no
>> matter what architect we have. Actually, the filter name ("exit_reason")
>> is only applicable to x86, meaning it's broken on other architects
>> including aarch64.
>>
>> This fixes the issue by providing various kvm_exit filter names, depending
>> on architect we're on. Afterwards, the variable filter name is picked and
>> applied by ioctl(fd, SET_FILTER).
>>
>> Reported-by: Andrew Jones <drjones@redhat.com>
> 
> This wasn't reported by me - I was just the middleman. Credit should go
> to Jeff Bastian <jbastian@redhat.com>
> 

Sure. Paolo, please let me know if I need post a v3 to fix it up :)

>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>> ---
>> v2: Rename exit_field to exit_reason_field
>>      Fix the name to esr_ec for aarch64
>> ---
>>   tools/kvm/kvm_stat/kvm_stat | 8 ++++++--
>>   1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/kvm/kvm_stat/kvm_stat b/tools/kvm/kvm_stat/kvm_stat
>> index ad1b9e646c49..4cf93110c259 100755
>> --- a/tools/kvm/kvm_stat/kvm_stat
>> +++ b/tools/kvm/kvm_stat/kvm_stat
>> @@ -270,6 +270,7 @@ class ArchX86(Arch):
>>       def __init__(self, exit_reasons):
>>           self.sc_perf_evt_open = 298
>>           self.ioctl_numbers = IOCTL_NUMBERS
>> +        self.exit_reason_field = 'exit_reason'
>>           self.exit_reasons = exit_reasons
>>   
>>       def debugfs_is_child(self, field):
>> @@ -289,6 +290,7 @@ class ArchPPC(Arch):
>>           # numbers depend on the wordsize.
>>           char_ptr_size = ctypes.sizeof(ctypes.c_char_p)
>>           self.ioctl_numbers['SET_FILTER'] = 0x80002406 | char_ptr_size << 16
>> +        self.exit_reason_field = 'exit_nr'
>>           self.exit_reasons = {}
>>   
>>       def debugfs_is_child(self, field):
>> @@ -300,6 +302,7 @@ class ArchA64(Arch):
>>       def __init__(self):
>>           self.sc_perf_evt_open = 241
>>           self.ioctl_numbers = IOCTL_NUMBERS
>> +        self.exit_reason_field = 'esr_ec'
>>           self.exit_reasons = AARCH64_EXIT_REASONS
>>   
>>       def debugfs_is_child(self, field):
>> @@ -311,6 +314,7 @@ class ArchS390(Arch):
>>       def __init__(self):
>>           self.sc_perf_evt_open = 331
>>           self.ioctl_numbers = IOCTL_NUMBERS
>> +        self.exit_reason_field = None
>>           self.exit_reasons = None
>>   
>>       def debugfs_is_child(self, field):
>> @@ -541,8 +545,8 @@ class TracepointProvider(Provider):
>>           """
>>           filters = {}
>>           filters['kvm_userspace_exit'] = ('reason', USERSPACE_EXIT_REASONS)
>> -        if ARCH.exit_reasons:
>> -            filters['kvm_exit'] = ('exit_reason', ARCH.exit_reasons)
>> +        if ARCH.exit_reason_field and ARCH.exit_reasons:
>> +            filters['kvm_exit'] = (ARCH.exit_reason_field, ARCH.exit_reasons)
>>           return filters
>>   
>>       def _get_available_fields(self):
>> -- 
>> 2.23.0
>>
> 
> Looks like a reasonable fix to me.
> 
> Reviewed-by: Andrew Jones <drjones@redhat.com>
> 

Thanks for the review and comments.

Regards,
Gavin