Re: [Qemu-arm] [Qemu-devel] [PATCH 2/2] arm/virt: Mark pcie controller node as dma-coherent

[Mihai Claudiu Caraman]

> -----Original Message-----
> From: Peter Maydell [mailto:address@hidden 
> Sent: Friday, June 03, 2016 5:38 PM
> To: Mihai Claudiu Caraman <address@hidden>
> Cc: Bogdan Purcareata <address@hidden>; QEMU Developers <address@hidden>; 
> Peter Crosthwaite <address@hidden>; Alexander Graf <address@hidden>; qemu-arm 
> <address@hidden>; Eric Auger <address@hidden>
> Subject: Re: [Qemu-devel] [PATCH 2/2] arm/virt: Mark pcie controller node as 
> dma-coherent
> 
> On 3 June 2016 at 15:22, Mihai Claudiu Caraman <address@hidden> wrote:
> > In particular for virtual and emulated devices the host CPU behaves as 
> > a DMA coherent 'device'. This should have been stated in patch 
> > description.
> 
> Wouldn't that imply that we should just always have the "dma-coherent"
> property set, and we don't need to do any of the messing around looking at 
> the host sysfs ?
> 
> thanks
> -- PMM

We can always set "dma-coherent" for virtual and emulated devices but not for 
passthrough devices. So we can't have one PCIe controller for all devices 
marked as "dma-coherent".

Regards,
Mike