Re: [PATCH V12 3/7] dma: add Qualcomm Technologies HIDMA management driver

From: Marc Zyngier
Date: Mon Jan 18 2016 - 04:06:26 EST


On 15/01/16 22:47, Sinan Kaya wrote:
> On 1/15/2016 12:32 PM, Marc Zyngier wrote:
>>>> Do you have a link to that? Seeing it would help to ease my concerns.
>>>>
>>>> The QEMU driver has not been posted yet. As far as I know, it just discovers the memory
>>>> resources on the platform object and creates mappings for the guest machine only.
>>>>
>>>> Shanker Donthineni and Vikram Sethi will post the QEMU patch later.
>> Then may I suggest you both synchronize your submissions? I'd really
>> like to hear from the QEMU maintainers that they are satisfied with that
>> side of the story as well.
>
> The HIDMA QEMU driver is also based on VFIO platform driver in QEMU. It is not a new concept
> or new framework. All tried and tested solutions.
>
> The driver below is already using this feature. HIDMA is no exception.
> I have verified functionality of HIDMA linux driver with HIDMA QEMU driver already.

That you have tested what you propose is the minimum you can do.

> https://lxr.missinglinkelectronics.com/qemu/hw/arm/sysbus-fdt.c#L67
> https://lxr.missinglinkelectronics.com/qemu/hw/vfio/calxeda-xgmac.c#L18
> https://lxr.missinglinkelectronics.com/qemu/include/hw/vfio/vfio-calxeda-xgmac.h

None of which warrants that what you're doing is the right thing. Since
nobody has seen your QEMU code, I'm not going to take any bet.

Thanks,

M.
--
Jazz is not dead. It just smells funny...