[PATCH 1/2] irqchip/gicv3-its: Support share device ID

[Minghuan.Lian at freescale.com]

Hi Marc and Varun,

Thank you very much for your valuable comments.
I will study further and try to find a better way to support ls2085 msi.

Thanks,
Minghuan

> -----Original Message-----
> From: Sethi Varun-B16395
> Sent: Friday, April 17, 2015 2:38 AM
> To: Marc Zyngier; Lian Minghuan-B31939
> Cc: Jason Cooper; Arnd Bergmann; linux-pci at vger.kernel.org; Will Deacon;T
> Yoder Stuart-B08248; Wood Scott-B07421; Bjorn Helgaas; Hu Mingkai-B21284;
> Zang Roy-R61911; Thomas Gleixner; linux-arm-kernel at lists.infradead.org
> Subject: RE: [PATCH 1/2] irqchip/gicv3-its: Support share device ID
> 
> Hi Minghuan,
> 
> > -----Original Message-----
> > From: linux-arm-kernel [mailto:linux-arm-kernel-
> > bounces at lists.infradead.org] On Behalf Of Marc Zyngier
> > Sent: Thursday, April 16, 2015 5:21 PM
> > To: Lian Minghuan-B31939
> > Cc: Jason Cooper; Arnd Bergmann; linux-pci at vger.kernel.org; Will
> > Deacon; Yoder Stuart-B08248; Wood Scott-B07421; Bjorn Helgaas; Hu
> > Mingkai-B21284; Zang Roy-R61911; Thomas Gleixner;
> > linux-arm-kernel at lists.infradead.org
> > Subject: Re: [PATCH 1/2] irqchip/gicv3-its: Support share device ID
> >
> > Minghuan,
> >
> > On 16/04/15 11:57, Minghuan.Lian at freescale.com wrote:
> >
> > Please include the relevant people (Will Deacon for questions about
> > the SMMU), and avoid top posting, it makes it very hard to follow a
> discussion.
> >
> > > I still have a couple of questions,
> > > 1. If I add a new flag and all PCI DEVID will be replaced with a
> > > fixed ID,  does SMMU can work correctly? For example, If we insert
> > > an Ethernet card with two ports, a port is assigned to kvm1, another
> > > port is assigned to kvm2. In this case, we should use one or two fixed ID?
> >
> > That completely depends on what the SMMU sees. If it sees the same ID,
> > you won't be able to perform any form of isolation. But I have no idea
> > how your hardware works, so maybe explaining in details how this is
> > constructed will help.
> >
> 
> We would need separate stream IDs and iommu groups for endpoints, to
> assign them to different VMs. We would have to set up the stream ID to
> device ID translation table during device probe, via add_device callback.
> While setting the device id for the interrupt translation table, you would have
> to get streamID corresponding to a given PCIe device ID. Again, I don't think
> that we should consider the TBUID, while setting the ITT device id.
> 
> -Varun