Re: [Qemu-devel] [PATCH v5] s390x/pci: add common function measurement block

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

On 19/12/2018 15:22, Cornelia Huck wrote:
> On Wed, 19 Dec 2018 13:57:05 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
>> From: Yi Min Zhao <zyimin@linux.ibm.com>
>>
>> Common function measurement block is used to report zPCI internal
>> counters of successful pcilg/stg/stb and rpcit instructions to
>> a memory location provided by the program.
>>
>> This patch introduces a new ZpciFmb structure and schedules a timer
>> callback to copy the zPCI measures to the FMB in the guest memory
>> at an interval time set to 4s.
>>
>> An error while attemping to update the FMB, would generate an error
>> event to the guest.
>>
>> The pcilg/stg/stb and rpcit interception handlers increase the
>> related counter on a successful call.
>> The guest shall pass a null FMBA (FMB address) in the FIB (Function
>> Information Block) when it issues a Modify PCI Function Control
>> instruction to switch off FMB and stop the corresponding timer.
>>
>> Signed-off-by: Yi Min Zhao <zyimin@linux.ibm.com>
>> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
>> ---
>>   hw/s390x/s390-pci-bus.c  |   4 +-
>>   hw/s390x/s390-pci-bus.h  |  29 +++++++++++
>>   hw/s390x/s390-pci-inst.c | 129 +++++++++++++++++++++++++++++++++++++++++++++--
>>   hw/s390x/s390-pci-inst.h |   1 +
>>   4 files changed, 159 insertions(+), 4 deletions(-)
>>
> 
>> +static void fmb_update(void *opaque)
>> +{
>> +    S390PCIBusDevice *pbdev = opaque;
>> +    int64_t t = qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL);
>> +    int i;
>> +
>> +    /* Update U bit */
>> +    pbdev->fmb.last_update *= 2;
>> +    pbdev->fmb.last_update |= UPDATE_U_BIT;
>> +    if (fmb_do_update(pbdev, offsetof(ZpciFmb, last_update),
>> +                      pbdev->fmb.last_update, sizeof(uint64_t))) {
> 
> Uh... the size of the last_update field would make more sense here...
> Also for the other fields below. Is there a reason that does not work?

None, I send a v6 :)



-- 
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany