linux-kernel - Re: [PATCH 3/7] iommu/vt-d: Enhance compatibility check for paging domain attach

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: <20241014192436.GD1825128@ziepe.ca>
Date: Mon, 14 Oct 2024 16:24:36 -0300
From: Jason Gunthorpe <jgg@...pe.ca>
To: Baolu Lu <baolu.lu@...ux.intel.com>
Cc: iommu@...ts.linux.dev, Joerg Roedel <joro@...tes.org>,
	Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
	Kevin Tian <kevin.tian@...el.com>, Yi Liu <yi.l.liu@...el.com>,
	Vasant Hegde <vasant.hegde@....com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/7] iommu/vt-d: Enhance compatibility check for paging
 domain attach

On Mon, Oct 14, 2024 at 09:25:03AM +0800, Baolu Lu wrote:
> > > +	if (domain->type & __IOMMU_DOMAIN_PAGING) {
> > 
> > It looks like this entire function is already never called for
> > anything but paging?
> > 
> > The only three callers are:
> > 
> > 	.default_domain_ops = &(const struct iommu_domain_ops) {
> > 		.attach_dev		= intel_iommu_attach_device,
> > 		.set_dev_pasid		= intel_iommu_set_dev_pasid,
> > 
> > and
> > 
> > static const struct iommu_domain_ops intel_nested_domain_ops = {
> > 	.attach_dev		= intel_nested_attach_dev,
> > 
> > And none of those cases can be anything except a paging domain by
> > definition.
> 
> A nested domain is not a paging domain. It represents a user-space page
> table that nested on a parent paging domain. Perhaps I overlooked
> anything?

It only calls it on the s2_parent which is always a paging domain?

	ret = prepare_domain_attach_device(&dmar_domain->s2_domain->domain, dev);

Jason