linux-kernel - Re: [PATCH v5 06/13] iommufd: Allow pt_id to carry viommu_id for IOMMU_HWPT

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: <20241029185357.GY6956@nvidia.com>
Date: Tue, 29 Oct 2024 15:53:57 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Nicolin Chen <nicolinc@...dia.com>
Cc: Zhangfei Gao <zhangfei.gao@...aro.org>, kevin.tian@...el.com,
	will@...nel.org, joro@...tes.org, suravee.suthikulpanit@....com,
	robin.murphy@....com, dwmw2@...radead.org, baolu.lu@...ux.intel.com,
	shuah@...nel.org, linux-kernel@...r.kernel.org,
	iommu@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
	linux-kselftest@...r.kernel.org, eric.auger@...hat.com,
	jean-philippe@...aro.org, mdf@...nel.org, mshavit@...gle.com,
	shameerali.kolothum.thodi@...wei.com, smostafa@...gle.com,
	yi.l.liu@...el.com, aik@....com, patches@...ts.linux.dev
Subject: Re: [PATCH v5 06/13] iommufd: Allow pt_id to carry viommu_id for
 IOMMU_HWPT_ALLOC

On Tue, Oct 29, 2024 at 09:07:38AM -0700, Nicolin Chen wrote:
> On Tue, Oct 29, 2024 at 12:27:46PM -0300, Jason Gunthorpe wrote:
> > On Mon, Oct 28, 2024 at 07:52:10AM -0700, Nicolin Chen wrote:
> > > On Mon, Oct 28, 2024 at 10:03:09AM -0300, Jason Gunthorpe wrote:
> > > In iommufd_hwpt_paging_alloc(), we reject IOMMU_HWPT_FAULT_ID_VALID:
> > > 	const u32 valid_flags = IOMMU_HWPT_ALLOC_NEST_PARENT |
> > > 				IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
> > > 	...
> > > 	if (flags & ~valid_flags)
> > > 		return ERR_PTR(-EOPNOTSUPP);
> > > 
> > > In iommufd_hwpt_nested_alloc(), we mask the flag away:
> > > 	if ((flags & ~IOMMU_HWPT_FAULT_ID_VALID) ||
> > > 	    !user_data->len || !ops->domain_alloc_user)
> > > 		return ERR_PTR(-EOPNOTSUPP);
> > > 	...
> > > 	hwpt->domain = ops->domain_alloc_user(idev->dev,
> > > 					      flags & ~IOMMU_HWPT_FAULT_ID_VALID,
> > > 					      parent->common.domain, user_data);
> > > 
> > > Then, in the common function it has a section of
> > > 	if (cmd->flags & IOMMU_HWPT_FAULT_ID_VALID) {
> > > 	...
> > > 
> > > It seems that this IOMMU_HWPT_FAULT_ID_VALID is for nested domains?
> > 
> > OK, but ARM should be blocking it since it doesn't work there.
> > 
> > I think we made some error here, it should have been passed in flags
> > to the drivers and only intel should have accepted it.
> 
> Trying to limit changes here since two parts are already quite
> large, I think a separate series fixing that would be nicer? 

Yes, let's just make a note

> > This suggests we should send flags down the viommu alloc domain path too.
> 
> Ack. Will pass it in.

But this would be nice to get to

Jason