Re: [PATCH] esp: fix migration version check in esp_is_version_5()

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 14/06/2021 06:42, Philippe Mathieu-Daudé wrote:

> On 6/13/21 12:26 PM, Mark Cave-Ayland wrote:
>> Commit 4e78f3bf35 "esp: defer command completion interrupt on incoming data
>> transfers" added a version check for use with VMSTATE_*_TEST macros to allow
>> migration from older QEMU versions. Unfortunately the version check fails to
>> work in its current form since if the VMStateDescription version_id is
>> incremented, the test returns false and so the fields are not included in the
>> outgoing migration stream.
>>
>> Change the version check to use >= rather == to ensure that migration works
>> correctly when the ESPState VMStateDescription has version_id > 5.
>>
>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>> Fixes: 4e78f3bf35 ("esp: defer command completion interrupt on incoming data transfers")
>> ---
> Well, it is not buggy yet :)

:)

>>   hw/scsi/esp.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
>> index bfdb94292b..39756ddd99 100644
>> --- a/hw/scsi/esp.c
>> +++ b/hw/scsi/esp.c
>> @@ -1120,7 +1120,7 @@ static bool esp_is_version_5(void *opaque, int version_id)
> 
> Can you rename esp_is_at_least_version_5()?

Sure, I can rename it if you like but it will of course make the diff noisier. 
esp_is_at_least_version_5() seems quite a mouthful though, what about 
esp_min_version_5() instead?

>>       ESPState *s = ESP(opaque);
>>   
>>       version_id = MIN(version_id, s->mig_version_id);
>> -    return version_id == 5;
>> +    return version_id >= 5;
>>   }
>>   
>>   int esp_pre_save(void *opaque)


ATB,

Mark.