From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Tian, Kevin" <kevin.tian@intel.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>,
Baolu Lu <baolu.lu@linux.intel.com>,
"iommu@lists.linux.dev" <iommu@lists.linux.dev>,
"joro@8bytes.org" <joro@8bytes.org>,
"will@kernel.org" <will@kernel.org>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"suravee.suthikulpanit@amd.com" <suravee.suthikulpanit@amd.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"jacob.pan@linux.microsoft.com" <jacob.pan@linux.microsoft.com>
Subject: Re: [PATCH v2 0/8] iommu: Domain allocation enhancements
Date: Fri, 11 Oct 2024 08:39:01 -0300 [thread overview]
Message-ID: <20241011113901.GI762027@ziepe.ca> (raw)
In-Reply-To: <BN9PR11MB52765C7FB8A106FCC7E944E98C792@BN9PR11MB5276.namprd11.prod.outlook.com>
On Fri, Oct 11, 2024 at 05:06:29AM +0000, Tian, Kevin wrote:
> > It is a bug in the implementation in the intel driver.
> >
> > intel_iommu_domain_alloc_user() should always allocate a page table
> > that works, if you are in a guest context it must allocate a first
> > level/guest page table otherwise nested VFIO will be broken.
>
> I don't think it's a bug. If nested is broken then VMM can fall back
> to the shadowing approach. If the VMM only supports nested
> then the only way to guarantee it is to not advertise 2nd-level
> capability on the vIOMMU.
Right, which is the bug, the alloc function isn't checking the
capabilities of the HW before going ahead to allocate a table format.
So it can choose a table format the HW doesn't advertise support
for. Whoops.
Jason
next prev parent reply other threads:[~2024-10-11 11:39 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-11 10:19 [PATCH v2 0/8] iommu: Domain allocation enhancements Vasant Hegde
2024-09-11 10:19 ` [PATCH v2 1/8] iommu: Refactor __iommu_domain_alloc() Vasant Hegde
2024-09-12 1:50 ` Baolu Lu
2024-09-13 4:02 ` Jacob Pan
2024-09-26 10:17 ` Vasant Hegde
2024-09-30 17:55 ` Jacob Pan
2024-10-01 4:31 ` Vasant Hegde
2024-10-02 5:11 ` Jacob Pan
[not found] ` <66fae60d.170a0220.280357.3d11SMTPIN_ADDED_BROKEN@mx.google.com>
2024-10-02 14:19 ` Jason Gunthorpe
2024-10-02 16:16 ` Jacob Pan
2024-10-02 19:09 ` Jason Gunthorpe
2024-10-15 8:12 ` Tian, Kevin
2024-09-11 10:19 ` [PATCH v2 2/8] iommu: Introduce iommu_paging_domain_alloc_flags() Vasant Hegde
2024-09-12 4:04 ` Baolu Lu
2024-09-26 10:43 ` Vasant Hegde
2024-10-15 8:24 ` Tian, Kevin
2024-10-15 12:31 ` Jason Gunthorpe
2024-10-16 2:44 ` Tian, Kevin
2024-10-02 19:12 ` Jason Gunthorpe
2024-10-09 21:14 ` Jacob Pan
2024-10-16 10:14 ` Vasant Hegde
2024-09-11 10:19 ` [PATCH v2 3/8] iommu: Add new flag to explictly request PASID capable domain Vasant Hegde
2024-09-12 4:14 ` Baolu Lu
2024-09-26 10:29 ` Vasant Hegde
2024-09-26 11:01 ` Vasant Hegde
2024-10-02 14:23 ` Jason Gunthorpe
2024-10-02 19:02 ` Jacob Pan
[not found] ` <66fd98e3.170a0220.23d7ae.c2a9SMTPIN_ADDED_BROKEN@mx.google.com>
2024-10-02 19:07 ` Jason Gunthorpe
2024-10-03 16:00 ` Jacob Pan
2024-10-02 19:23 ` Jason Gunthorpe
2024-10-04 8:12 ` Vasant Hegde
2024-10-04 12:46 ` Jason Gunthorpe
2024-10-15 8:31 ` Tian, Kevin
2024-09-11 10:19 ` [PATCH v2 4/8] iommu/amd: Separate page table setup from domain allocation Vasant Hegde
2024-09-13 17:08 ` Jacob Pan
2024-10-02 19:24 ` Jason Gunthorpe
2024-09-11 10:19 ` [PATCH v2 5/8] iommu/amd: Pass page table type as param to pdom_setup_pgtable() Vasant Hegde
2024-09-13 21:39 ` Jacob Pan
2024-09-26 10:25 ` Vasant Hegde
2024-09-30 17:57 ` Jacob Pan
[not found] ` <66e4b125.170a0220.2fa213.1e2cSMTPIN_ADDED_BROKEN@mx.google.com>
2024-09-20 13:02 ` Jason Gunthorpe
2024-09-11 10:19 ` [PATCH v2 6/8] iommu/amd: Enhance domain_alloc_user() to allocate PASID capable domain Vasant Hegde
2024-10-02 19:31 ` Jason Gunthorpe
2024-10-04 8:18 ` Vasant Hegde
2024-10-04 12:48 ` Jason Gunthorpe
2024-10-04 14:32 ` Vasant Hegde
2024-10-15 8:41 ` Tian, Kevin
2024-10-15 12:40 ` Jason Gunthorpe
2024-10-16 2:48 ` Tian, Kevin
2024-10-16 15:28 ` Jason Gunthorpe
2024-10-17 6:11 ` Tian, Kevin
2024-10-17 11:03 ` Vasant Hegde
2024-09-11 10:19 ` [PATCH v2 7/8] iommu/amd: Add iommu_ops->domain_alloc_paging support Vasant Hegde
2024-10-02 19:33 ` Jason Gunthorpe
2024-10-04 11:55 ` Vasant Hegde
2024-10-04 12:56 ` Jason Gunthorpe
2024-10-04 14:30 ` Vasant Hegde
2024-10-04 15:31 ` Jason Gunthorpe
2024-10-08 10:08 ` Vasant Hegde
2024-09-11 10:19 ` [PATCH v2 8/8] iommu/amd: Implement global identity domain Vasant Hegde
2024-10-02 19:36 ` Jason Gunthorpe
2024-10-04 11:42 ` Vasant Hegde
2024-10-02 5:30 ` [PATCH v2 0/8] iommu: Domain allocation enhancements Vasant Hegde
2024-10-02 14:24 ` Jason Gunthorpe
2024-10-04 6:11 ` Vasant Hegde
2024-10-09 2:47 ` Baolu Lu
2024-10-09 9:53 ` Vasant Hegde
2024-10-09 12:15 ` Jason Gunthorpe
2024-10-10 6:40 ` Baolu Lu
2024-10-10 6:48 ` Baolu Lu
2024-10-10 11:38 ` Jason Gunthorpe
2024-10-10 14:06 ` Baolu Lu
2024-10-11 5:06 ` Tian, Kevin
2024-10-11 11:39 ` Jason Gunthorpe [this message]
2024-10-15 8:10 ` Tian, Kevin
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