Re: [Qemu-devel] [PATCH v1 06/12] net: cadence_gem: Add support for selecting the DMA MemoryRegion

From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
	QEMU Developers <qemu-devel@nongnu.org>,
	qemu-arm <qemu-arm@nongnu.org>,
	Richard Henderson <richard.henderson@linaro.org>,
	KONRAD Frederic <frederic.konrad@adacore.com>,
	Alistair Francis <alistair@alistair23.me>,
	Francisco Iglesias <frasse.iglesias@gmail.com>,
	figlesia@xilinx.com, Stefano Stabellini <sstabellini@kernel.org>,
	Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Subject: Re: [Qemu-devel] [PATCH v1 06/12] net: cadence_gem: Add support for selecting the DMA MemoryRegion
Date: Mon, 8 Oct 2018 21:54:02 +0200	[thread overview]
Message-ID: <20181008195402.GA4229@toto> (raw)
In-Reply-To: <CAFEAcA-tC0wHgkh+CA2s+G015kvdd47h-R+VCbjCRRZVTsUghA@mail.gmail.com>

On Mon, Oct 08, 2018 at 01:24:51PM +0100, Peter Maydell wrote:
> On 3 October 2018 at 16:07, Edgar E. Iglesias <edgar.iglesias@gmail.com> wrote:
> > From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
> >
> > Add support for selecting the Memory Region that the GEM
> > will do DMA to.
> >
> > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
> > ---
> 
> 
> > @@ -1500,6 +1506,13 @@ static void gem_realize(DeviceState *dev, Error **errp)
> >      CadenceGEMState *s = CADENCE_GEM(dev);
> >      int i;
> >
> > +    if (s->dma_mr) {
> > +        s->dma_as = g_malloc0(sizeof(AddressSpace));
> > +        address_space_init(s->dma_as, s->dma_mr, NULL);
> 
> Why not just have the CadenceGEMState embed the AddressSpace
> 
>     AddressSpace dma_as;
> 
> rather than doing a separate memory allocation here?

No reason not to, I copied this from a pattern in our code and didn't reflect too much about the allocation.
I'll change it for next version.

Cheers,
Edgar

> 
> > +    } else {
> > +        s->dma_as = &address_space_memory;
> > +    }
> 
> thanks
> -- PMM