Messages in this thread | | | From | "Radovanovic, Aleksandar" <> | Subject | RE: [RFC PATCH v3 4/7] bus/cdx: add cdx-MSI domain with gic-its domain as parent | Date | Fri, 14 Oct 2022 12:13:45 +0000 |
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[AMD Official Use Only - General]
> -----Original Message----- > From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> > Sent: 14 October 2022 12:55 > To: Radovanovic, Aleksandar <aleksandar.radovanovic@amd.com> > Cc: Jason Gunthorpe <jgg@ziepe.ca>; Gupta, Nipun > <Nipun.Gupta@amd.com>; Marc Zyngier <maz@kernel.org>; Robin Murphy > <robin.murphy@arm.com>; robh+dt@kernel.org; > krzysztof.kozlowski+dt@linaro.org; rafael@kernel.org; > eric.auger@redhat.com; alex.williamson@redhat.com; cohuck@redhat.com; > Gupta, Puneet (DCG-ENG) <puneet.gupta@amd.com>; > song.bao.hua@hisilicon.com; mchehab+huawei@kernel.org; > f.fainelli@gmail.com; jeffrey.l.hugo@gmail.com; saravanak@google.com; > Michael.Srba@seznam.cz; mani@kernel.org; yishaih@nvidia.com; > will@kernel.org; joro@8bytes.org; masahiroy@kernel.org; > ndesaulniers@google.com; linux-arm-kernel@lists.infradead.org; linux- > kbuild@vger.kernel.org; linux-kernel@vger.kernel.org; > devicetree@vger.kernel.org; kvm@vger.kernel.org; okaya@kernel.org; > Anand, Harpreet <harpreet.anand@amd.com>; Agarwal, Nikhil > <nikhil.agarwal@amd.com>; Simek, Michal <michal.simek@amd.com>; git > (AMD-Xilinx) <git@amd.com> > Subject: Re: [RFC PATCH v3 4/7] bus/cdx: add cdx-MSI domain with gic-its > domain as parent > > Caution: This message originated from an External Source. Use proper > caution when opening attachments, clicking links, or responding. > > > On Fri, Oct 14, 2022 at 11:18:36AM +0000, Radovanovic, Aleksandar wrote: > > Anyway, I think we're straying off topic here, none of this is visible to the > kernel anyway. The question that we still need to answer is, are you OK with > the limitations I listed originally? > > What original limitations?
Limitations with regards to MSI message configuration of a CDX device:
1) MSI write value is at most 16 useable bits
2) MSI address value must be the same across all vectors of a single CDX device This would be the (potentially IOMMU translated) I/O address of GITS_TRANSLATER. As long as that IOMMU translation is consistent across a single device, I think we should be OK.
> This thread is crazy and complex and you need to > use your \n key more :)
I do try, but the corporate mail client that we're stuck with seems to just merge everything back together. Sigh.
> thanks, > > greg k-h
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