Re: [Qemu-devel] [PATCH v5 06/10] hw/vfio: create common module

[Alexander Graf]

> Am 01.09.2014 um 18:31 schrieb Eric Auger <address@hidden>:
> 
>> On 08/13/2014 09:59 PM, Alex Williamson wrote:
>>> On Tue, 2014-08-12 at 08:09 +0200, Eric Auger wrote:
>>>> On 08/11/2014 09:25 PM, Alex Williamson wrote:
>>>>> On Sat, 2014-08-09 at 15:25 +0100, Eric Auger wrote:
>>>>> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
>>>>> new file mode 100644
>>>>> index 0000000..4684ee5
>>>>> --- /dev/null
>>>>> +++ b/include/hw/vfio/vfio-common.h
>>>>> @@ -0,0 +1,151 @@
>>>>> +/*
>>>>> + * common header for vfio based device assignment support
>>>>> + *
>>>>> + * Copyright Red Hat, Inc. 2012
>>>>> + *
>>>>> + * Authors:
>>>>> + *  Alex Williamson <address@hidden>
>>>>> + *
>>>>> + * This work is licensed under the terms of the GNU GPL, version 2.  See
>>>>> + * the COPYING file in the top-level directory.
>>>>> + *
>>>>> + * Based on qemu-kvm device-assignment:
>>>>> + *  Adapted for KVM by Qumranet.
>>>>> + *  Copyright (c) 2007, Neocleus, Alex Novik (address@hidden)
>>>>> + *  Copyright (c) 2007, Neocleus, Guy Zana (address@hidden)
>>>>> + *  Copyright (C) 2008, Qumranet, Amit Shah (address@hidden)
>>>>> + *  Copyright (C) 2008, Red Hat, Amit Shah (address@hidden)
>>>>> + *  Copyright (C) 2008, IBM, Muli Ben-Yehuda (address@hidden)
>>>>> + */
>>>>> +#ifndef HW_VFIO_VFIO_COMMON_H
>>>>> +#define HW_VFIO_VFIO_COMMON_H
>>>>> +
>>>>> +#include "qemu-common.h"
>>>>> +#include "exec/address-spaces.h"
>>>>> +#include "exec/memory.h"
>>>>> +#include "qemu/queue.h"
>>>>> +#include "qemu/notify.h"
>>>>> +
>>>>> +/*#define DEBUG_VFIO*/
>>>>> +#ifdef DEBUG_VFIO
>>>>> +#define DPRINTF(fmt, ...) \
>>>>> +    do { fprintf(stderr, "vfio: " fmt, ## __VA_ARGS__); } while (0)
>>>>> +#else
>>>>> +#define DPRINTF(fmt, ...) \
>>>>> +    do { } while (0)
>>>>> +#endif
>>>> 
>>>> 
>>>> DPRINTF also need to be renamed to avoid conflicting namespace issues.
>>> Ji Alex,
>>> 
>>> OK.
>>> 
>>> As I am going to touch at traces,
>>> - are you OK if I use the new .name field to simply format strings?
>> 
>> Sure, that's fine.
>> 
>>>    DPRINTF("%s(%04x:%02x:%02x.%x) Pin %c\n", __func__, vdev->host.domain,
>>>            vdev->host.bus, vdev->host.slot, vdev->host.function,
>>>            'A' + vdev->intx.pin);
>>> - Also Alex was suggesting to use trace points. What is your position
>>> about that? Also I am not 100% sure of what it consists in? is it trace
>>> events as documented in docs/tracing.txt
>> 
>> I think it would be a great conversion, but it's not required.  Thanks,
> 
> Hi Alex,
> 
> I am currently progressing on the conversion to trace points (I did it
> for platform and common and now do the job for PCI). I wonder whether it
> makes sense I convert all DPRINTF into trace-points or only convert a
> subset (state transitions, ...). Would you accept a mixture of DPRINTFs
> and trace-points or do you advise to convert everything?

Yeah, it's perfectly good to even just nit introduce new dprintfs.

> 
> Also the tracing.txt doc says we should use the name of the function as
> prefix. That being said it could be interesting to trace all pci* or all
> platform* and wildcard seems to work fine to select the trace-events. So
> my second question is would you accept using pci_<function_name>_* as a
> generic pattern.

Not sure - maybe be more explicit and call it vfio_pci_...?


Alex

> 
> Thanks in advance
> 
> Best Regards
> 
> Eric
>> 
>> Alex
>