From: Jason Gunthorpe <jgg@nvidia.com>
To: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux.dev,
joro@8bytes.org, yi.l.liu@intel.com, kevin.tian@intel.com,
nicolinc@nvidia.com, vasant.hegde@amd.com, jon.grimm@amd.com,
santosh.shukla@amd.com, sairaj.arunkodilkar@amd.com,
jay.chen@amd.com, wvw@google.com, wnliu@google.com,
dantuluris@google.com, chriscli@google.com, kpsingh@google.com
Subject: Re: [PATCH v3 19/22] iommu/amd: Add per-segment translate device ID pool
Date: Tue, 7 Jul 2026 11:36:59 -0300 [thread overview]
Message-ID: <20260707143659.GG220801@nvidia.com> (raw)
In-Reply-To: <20260629153535.15775-20-suravee.suthikulpanit@amd.com>
On Mon, Jun 29, 2026 at 03:35:32PM +0000, Suravee Suthikulpanit wrote:
> Track translate-device-id slots per PCI segment so real PCI device IDs can
> be reserved for normal DTE programming and excluded from dynamic allocation
> for vIOMMU translation DTEs.
Why does it have to be per segment? The segment is encoded in the
devid isn't it?
This seems like a sketchy design to me, is it impossible to atomically
change the viommu used devids once they start being used? It seems
like this should be doable
If so the algorithm would be simpler, just maintain an xarray of all
dev ids, if the entry is marked as a VIOMMU and PCI needs it then move
the VIOMMU out of the way and use the entry for PCI.
No need to try to guess what ranges are usable or not.
Jason
next prev parent reply other threads:[~2026-07-07 14:37 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-29 15:35 [PATCH v3 00/22] iommu/amd: Introduce AMD Hardware-accelerated Virtualized IOMMU (vIOMMU) Support Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 01/22] iommu/amd: Make amd_iommu_completion_wait() non-static Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 02/22] iommu/amd: Introduce vIOMMU-specific events and event Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 03/22] iommu/amd: Detect and initialize AMD vIOMMU feature Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 04/22] iommu/amd: Introduce IOMMUFD vIOMMU support for AMD Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 05/22] iommu/amd: Allocate Guest IDs for IOMMUFD vIOMMU instances Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 06/22] iommu/amd: Map vIOMMU VF and VF Control MMIO BARs Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 07/22] iommu/amd: Add support for AMD vIOMMU VF MMIO region Suravee Suthikulpanit
2026-07-07 14:33 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 08/22] iommu/amd: Introduce Reset vMMIO Command Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 09/22] iommu/amd: Introduce and map vIOMMU private IPA region Suravee Suthikulpanit
2026-07-07 14:07 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 10/22] iommu/amd: Pass iommu to device_flush_dte() Suravee Suthikulpanit
2026-07-07 14:18 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 11/22] iommu/amd: Export amd_iommu_alloc_dev_data() helper Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 12/22] iommu/amd: Pass iommu and devid to amd_iommu_make_clear_dte() Suravee Suthikulpanit
2026-07-07 14:20 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 13/22] iommu/amd: Assign IOMMU Private Address domain to IOMMU Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 14/22] iommu/amd: Add per-VM private IPA alloc/map helpers Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 15/22] iommu/amd: Add helper functions to manage DevID / DomID mapping tables Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 16/22] iommu/amd: Introduce IOMMUFD vDevice support for AMD Suravee Suthikulpanit
2026-07-07 14:31 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 17/22] iommu/amd: Introduce helper function for updating domain ID mapping table Suravee Suthikulpanit
2026-07-07 14:32 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 18/22] iommu/amd: Introduce helper function for updating device " Suravee Suthikulpanit
2026-06-29 15:35 ` [PATCH v3 19/22] iommu/amd: Add per-segment translate device ID pool Suravee Suthikulpanit
2026-07-07 14:36 ` Jason Gunthorpe [this message]
2026-06-29 15:35 ` [PATCH v3 20/22] iommu/amd: Reserve translate-device-id for PCI requestor aliases Suravee Suthikulpanit
2026-07-07 14:39 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 21/22] iommu/amd: Add translation DTE and VFctrl TransDevID helpers Suravee Suthikulpanit
2026-07-07 14:43 ` Jason Gunthorpe
2026-06-29 15:35 ` [PATCH v3 22/22] iommu/amd: Assign per-vIOMMU translate device ID Suravee Suthikulpanit
2026-07-07 14:45 ` [PATCH v3 00/22] iommu/amd: Introduce AMD Hardware-accelerated Virtualized IOMMU (vIOMMU) Support Jason Gunthorpe
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