linux-kernel - Re: [PATCH RFCv2 05/13] iommu: Turn fault

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: <20250123132532.GK5556@nvidia.com>
Date: Thu, 23 Jan 2025 09:25:32 -0400
From: Jason Gunthorpe <jgg@...dia.com>
To: "Tian, Kevin" <kevin.tian@...el.com>
Cc: Nicolin Chen <nicolinc@...dia.com>, "will@...nel.org" <will@...nel.org>,
	"robin.murphy@....com" <robin.murphy@....com>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"maz@...nel.org" <maz@...nel.org>,
	"alex.williamson@...hat.com" <alex.williamson@...hat.com>,
	"joro@...tes.org" <joro@...tes.org>,
	"shuah@...nel.org" <shuah@...nel.org>,
	"Chatre, Reinette" <reinette.chatre@...el.com>,
	"eric.auger@...hat.com" <eric.auger@...hat.com>,
	"yebin10@...wei.com" <yebin10@...wei.com>,
	"apatel@...tanamicro.com" <apatel@...tanamicro.com>,
	"shivamurthy.shastri@...utronix.de" <shivamurthy.shastri@...utronix.de>,
	"bhelgaas@...gle.com" <bhelgaas@...gle.com>,
	"anna-maria@...utronix.de" <anna-maria@...utronix.de>,
	"yury.norov@...il.com" <yury.norov@...il.com>,
	"nipun.gupta@....com" <nipun.gupta@....com>,
	"iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" <linux-arm-kernel@...ts.infradead.org>,
	"kvm@...r.kernel.org" <kvm@...r.kernel.org>,
	"linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
	"patches@...ts.linux.dev" <patches@...ts.linux.dev>,
	"jean-philippe@...aro.org" <jean-philippe@...aro.org>,
	"mdf@...nel.org" <mdf@...nel.org>,
	"mshavit@...gle.com" <mshavit@...gle.com>,
	"shameerali.kolothum.thodi@...wei.com" <shameerali.kolothum.thodi@...wei.com>,
	"smostafa@...gle.com" <smostafa@...gle.com>,
	"ddutile@...hat.com" <ddutile@...hat.com>
Subject: Re: [PATCH RFCv2 05/13] iommu: Turn fault_data to iommufd private
 pointer

On Thu, Jan 23, 2025 at 09:54:38AM +0000, Tian, Kevin wrote:
> > From: Nicolin Chen <nicolinc@...dia.com>
> > Sent: Saturday, January 11, 2025 11:32 AM
> > 
> > @@ -224,8 +224,10 @@ struct iommu_domain {
> >  		      phys_addr_t msi_addr);
> >  #endif
> > 
> > -	void *fault_data;
> > -	union {
> > +	union { /* Pointer usable by owner of the domain */
> > +		struct iommufd_hw_pagetable *iommufd_hwpt; /* iommufd
> > */
> > +	};
> > +	union { /* Fault handler */
> 
> hmm is it better to rename it as "void *private;" and let the caller
> do type conversion?

I like the type safety, the union can hold other in-kernel users with
their proper types and this discourages drivers from inventing weird
things..

Jason