linux-kernel - Re: [PATCH v2 10/22] iommufd/viommmu: Add IOMMUFD_CMD_VCMDQ

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250507123333.GD90261@nvidia.com>
Date: Wed, 7 May 2025 09:33:33 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Nicolin Chen <nicolinc@...dia.com>
Cc: "Tian, Kevin" <kevin.tian@...el.com>,
	Vasant Hegde <vasant.hegde@....com>,
	"corbet@....net" <corbet@....net>,
	"will@...nel.org" <will@...nel.org>,
	"bagasdotme@...il.com" <bagasdotme@...il.com>,
	"robin.murphy@....com" <robin.murphy@....com>,
	"joro@...tes.org" <joro@...tes.org>,
	"thierry.reding@...il.com" <thierry.reding@...il.com>,
	"vdumpa@...dia.com" <vdumpa@...dia.com>,
	"jonathanh@...dia.com" <jonathanh@...dia.com>,
	"shuah@...nel.org" <shuah@...nel.org>,
	"jsnitsel@...hat.com" <jsnitsel@...hat.com>,
	"nathan@...nel.org" <nathan@...nel.org>,
	"peterz@...radead.org" <peterz@...radead.org>,
	"Liu, Yi L" <yi.l.liu@...el.com>,
	"mshavit@...gle.com" <mshavit@...gle.com>,
	"praan@...gle.com" <praan@...gle.com>,
	"zhangzekun11@...wei.com" <zhangzekun11@...wei.com>,
	"iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
	"linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>,
	"linux-tegra@...r.kernel.org" <linux-tegra@...r.kernel.org>,
	"linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
	"patches@...ts.linux.dev" <patches@...ts.linux.dev>,
	"mochs@...dia.com" <mochs@...dia.com>,
	"alok.a.tiwari@...cle.com" <alok.a.tiwari@...cle.com>,
	Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Subject: Re: [PATCH v2 10/22] iommufd/viommmu: Add IOMMUFD_CMD_VCMDQ_ALLOC
 ioctl

On Wed, May 07, 2025 at 12:37:57AM -0700, Nicolin Chen wrote:
> On Wed, May 07, 2025 at 07:25:41AM +0000, Tian, Kevin wrote:
> > > From: Nicolin Chen <nicolinc@...dia.com>
> > > Sent: Wednesday, May 7, 2025 4:13 AM
> > > 
> > > On Tue, May 06, 2025 at 09:25:59AM +0000, Tian, Kevin wrote:
> > > > > From: Nicolin Chen <nicolinc@...dia.com>
> > > > > Sent: Wednesday, April 30, 2025 1:15 AM
> > > > >
> > > > > On Tue, Apr 29, 2025 at 03:52:48PM +0530, Vasant Hegde wrote:
> > > > > > On 4/29/2025 12:15 PM, Nicolin Chen wrote:
> > > > > > > On Tue, Apr 29, 2025 at 11:04:06AM +0530, Vasant Hegde wrote:
> > > > > > >
> > > > > > > Will the hardware replace the physical device ID in the event with
> > > > > > > the virtual device ID when injecting the event to a guest event/PPR
> > > > > > > queue?
> > > > > > > If so, yea, I think you can define them separately using the> vCMDQ
> > > > > > infrastructures:
> > > > > > >  - IOMMU_VCMDQ_TYPE_AMD_VIOMMU_CMDBUF
> > > > > > >  - IOMMU_VCMDQ_TYPE_AMD_VIOMMU_EVENTLOG
> > > > > > >  - IOMMU_VCMDQ_TYPE_AMD_VIOMMU_PPRLOG
> > > > > > > (@Kevin @Jason Hmm, in this case we might want to revert the
> > > naming
> > > > > > >  "vCMDQ" back to "vQEUEUE", once Vasant confirms.)
> > > > >
> > > > > I think I should rename IOMMUFD_OBJ_VCMDQ back to
> > > > > IOMMUFD_OBJ_VQUEUE
> > > > > since the same object fits three types of queue now in the AMD case.
> > > > >
> > > > > Or any better naming suggestion?
> > > > >
> > > >
> > > > What about IOMMUFD_OBJ_HQUEUE to differentiate from other
> > > > pure software queue structs? 'H" stands for direct hw access to
> > > > the queue object.
> > > 
> > > I think it make some sense. There has been a concern of mine that
> > > some day we might need vQUEUE to deal with some non-HW-acced case,
> > > given "vQUEUE" is named much wider than what it actually supports.
> > > 
> > > Also, vEVENTQ and FAULT_QUEUE fit into the "QUEUE" category too..
> > > 
> > > Though "hQUEUE" would break the naming pattern that we have, 
> > 
> > what is the naming pattern here?
> 
> vIOMMU, vDEVICE, vEVENTQ, vCMDQ

You could just call it what it is, "DIRECT QUEUE" or something along
those lines to indicate it is mmap'd and so forth, vs being a SW queue
with read()/write()

HW QUEUE is good too

Jason