Changes in sysfs-kernel-iommu_groups

4c8444f1 - iommu: Cleanup iommu_change_dev_def_domain()

Wed, 22 Mar 2023 06:49:56 +0000

iommu: Cleanup iommu_change_dev_def_domain()As the singleton group limitation has been removed, cleanup the codein iommu_change_dev_def_domain() accordingly.Documentation is also updated.Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20230322064956.263419-7-baolu.lu@linux.intel.comSigned-off-by: Joerg Roedel List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

26225bea - iommu: Expose DMA domain strictness via sysfs

Wed, 11 Aug 2021 12:21:35 +0000

iommu: Expose DMA domain strictness via sysfsThe sysfs interface for default domain types exists primarily so userscan choose the performance/security tradeoff relevant to their ownworkload. As such, the choice between the policies for DMA domains fitsperfectly as an additional point on that scale - downgrading aparticular device from a strict default to non-strict may be enough tolet it reach the desired level of performance, while still retainingmore peace of mind than with a wide-open identity domain. Now that we'veabstracted non-strict mode as a distinct type of DMA domain, allow it tobe chosen through the user interface as well.Reviewed-by: Lu Baolu Reviewed-by: John Garry Signed-off-by: Robin Murphy Link: https://lore.kernel.org/r/0e08da5ed4069fd3473cfbadda758ca983becdbf.1628682049.git.robin.murphy@arm.comSigned-off-by: Joerg Roedel List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

5286bd25 - docs: ABI: iommu: remove duplicated definition for sysfs-kernel-iommu_groups

Wed, 19 May 2021 08:51:44 +0000

docs: ABI: iommu: remove duplicated definition for sysfs-kernel-iommu_groups./scripts/get_abi.pl is reporting a duplicated definition for/sys/kernel/iommu_groups/reserved_regions, both at the samefile: Warning: /sys/kernel/iommu_groups/reserved_regions is defined 2 times: Documentation/ABI/testing/sysfs-kernel-iommu_groups:15 Documentation/ABI/testing/sysfs-kernel-iommu_groups:27Fix it by merging those into an unified entry.Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/ec33e8e9b8f120232ffb3b9fcc99c97b87f242e3.1621413933.git.mchehab+huawei@kernel.orgSigned-off-by: Jonathan Corbet List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

62c9917d - iommu: Fix htmldocs warnings in sysfs-kernel-iommu_groups

Thu, 26 Nov 2020 09:06:03 +0000

iommu: Fix htmldocs warnings in sysfs-kernel-iommu_groupsBelow warnings are fixed:Documentation/ABI/testing/sysfs-kernel-iommu_groups:38: WARNING: Unexpected indentation.Documentation/ABI/testing/sysfs-kernel-iommu_groups:38: WARNING: Block quote ends without a blank line; unexpected unindent.Documentation/ABI/testing/sysfs-kernel-iommu_groups:38: WARNING: Enumerated list ends without a blank line; unexpected unindent.Documentation/ABI/testing/sysfs-kernel-iommu_groups:38: WARNING: Unexpected indentation.Documentation/ABI/testing/sysfs-kernel-iommu_groups:38: WARNING: Block quote ends without a blank line; unexpected unindent.Fixes: 63a816749d86 ("iommu: Document usage of "/sys/kernel/iommu_groups//type" file")Reported-by: Stephen Rothwell Link: https://lore.kernel.org/linux-next/20201126174851.200e0e58@canb.auug.org.au/Signed-off-by: Lu Baolu Link: https://lore.kernel.org/r/20201126090603.1511589-1-baolu.lu@linux.intel.comSigned-off-by: Will Deacon List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

63a81674 - iommu: Document usage of "/sys/kernel/iommu_groups//type" file

Tue, 24 Nov 2020 13:06:04 +0000

iommu: Document usage of "/sys/kernel/iommu_groups//type" fileThe default domain type of an iommu group can be changed by writing to"/sys/kernel/iommu_groups//type" file. Hence, document it's usageand more importantly spell out its limitations.Signed-off-by: Sai Praneeth Prakhya Signed-off-by: Lu Baolu Cc: Christoph Hellwig Cc: Joerg Roedel Cc: Ashok Raj Cc: Will Deacon Cc: Sohil Mehta Cc: Robin Murphy Cc: Jacob Pan Link: https://lore.kernel.org/r/20201124130604.2912899-5-baolu.lu@linux.intel.comSigned-off-by: Will Deacon List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

adfd3738 - iommu: Introduce IOMMU_RESV_DIRECT_RELAXABLE reserved memory regions

Mon, 03 Jun 2019 06:53:35 +0000

iommu: Introduce IOMMU_RESV_DIRECT_RELAXABLE reserved memory regionsIntroduce a new type for reserved region. This correspondsto directly mapped regions which are known to be relaxablein some specific conditions, such as device assignment usecase. Well known examples are those used by USB controllersproviding PS/2 keyboard emulation for pre-boot BIOS andearly BOOT or RMRRs associated to IGD working in legacy mode.Since commit c875d2c1b808 ("iommu/vt-d: Exclude devices using RMRRsfrom IOMMU API domains") and commit 18436afdc11a ("iommu/vt-d: AllowRMRR on graphics devices too"), those regions are currentlyconsidered "safe" with respect to device assignment use casewhich requires a non direct mapping at IOMMU physical level(RAM GPA -> HPA mapping).Those RMRRs currently exist and sometimes the device isattempting to access it but this has not been consideredan issue until now.However at the moment, iommu_get_group_resv_regions() isnot able to make any difference between directly mappedregions: those which must be absolutely enforced and thoselike above ones which are known as relaxable.This is a blocker for reporting severe conflicts betweennon relaxable RMRRs (like MSI doorbells) and guest GPA space.With this new reserved region type we will be able to useiommu_get_group_resv_regions() to enumerate the IOVA spacethat is usable through the IOMMU API without introducingregressions with respect to existing device assignmentuse cases (USB and IGD).Signed-off-by: Eric Auger Signed-off-by: Joerg Roedel List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

bc7d12b9 - iommu: Implement reserved_regions iommu-group sysfs file

Thu, 19 Jan 2017 20:57:52 +0000

iommu: Implement reserved_regions iommu-group sysfs fileA new iommu-group sysfs attribute file is introduced. It containsthe list of reserved regions for the iommu-group. Each reservedregion is described on a separate line:- first field is the start IOVA address,- second is the end IOVA address,- third is the type.Signed-off-by: Eric Auger Tested-by: Tomasz Nowicki Tested-by: Bharat Bhushan Signed-off-by: Will Deacon List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups

d72e31c9 - iommu: IOMMU Groups

Wed, 30 May 2012 20:18:53 +0000

iommu: IOMMU GroupsIOMMU device groups are currently a rather vague associative notionwith assembly required by the user or user level driver provider todo anything useful. This patch intends to grow the IOMMU group conceptinto something a bit more consumable.To do this, we first create an object representing the group, structiommu_group. This structure is allocated (iommu_group_alloc) andfilled (iommu_group_add_device) by the iommu driver. The iommu driveris free to add devices to the group using it's own set of policies.This allows inclusion of devices based on physical hardware or topologylimitations of the platform, as well as soft requirements, such asmulti-function trust levels or peer-to-peer protection of theinterconnects. Each device may only belong to a single iommu group,which is linked from struct device.iommu_group. IOMMU groups aremaintained using kobject reference counting, allowing for automaticremoval of empty, unreferenced groups. It is the responsibility ofthe iommu driver to remove devices from the group(iommu_group_remove_device).IOMMU groups also include a userspace representation in sysfs under/sys/kernel/iommu_groups. When allocated, each group is given adynamically assign ID (int). The ID is managed by the core IOMMU groupcode to support multiple heterogeneous iommu drivers, which couldpotentially collide in group naming/numbering. This also keeps groupIDs to small, easily managed values. A directory is created under/sys/kernel/iommu_groups for each group. A further subdirectory named"devices" contains links to each device within the group. The iommu_groupfile in the device's sysfs directory, which formerly contained a groupnumber when read, is now a link to the iommu group. Example:$ ls -l /sys/kernel/iommu_groups/26/devices/total 0lrwxrwxrwx. 1 root root 0 Apr 17 12:57 0000:00:1e.0 -> ../../../../devices/pci0000:00/0000:00:1e.0lrwxrwxrwx. 1 root root 0 Apr 17 12:57 0000:06:0d.0 -> ../../../../devices/pci0000:00/0000:00:1e.0/0000:06:0d.0lrwxrwxrwx. 1 root root 0 Apr 17 12:57 0000:06:0d.1 -> ../../../../devices/pci0000:00/0000:00:1e.0/0000:06:0d.1$ ls -l /sys/kernel/iommu_groups/26/devices/*/iommu_group[truncating perms/owner/timestamp]/sys/kernel/iommu_groups/26/devices/0000:00:1e.0/iommu_group -> ../../../kernel/iommu_groups/26/sys/kernel/iommu_groups/26/devices/0000:06:0d.0/iommu_group -> ../../../../kernel/iommu_groups/26/sys/kernel/iommu_groups/26/devices/0000:06:0d.1/iommu_group -> ../../../../kernel/iommu_groups/26Groups also include several exported functions for use by user leveldriver providers, for example VFIO. These include:iommu_group_get(): Acquires a reference to a group from a deviceiommu_group_put(): Releases referenceiommu_group_for_each_dev(): Iterates over group devices using callbackiommu_group_[un]register_notifier(): Allows notification of device add and remove operations relevant to the groupiommu_group_id(): Return the group numberThis patch also extends the IOMMU API to allow attaching groups todomains. This is currently a simple wrapper for iterating throughdevices within a group, but it's expected that the IOMMU API mayeventually make groups a more integral part of domains.Groups intentionally do not try to manage group ownership. A userlevel driver provider must independently acquire ownership for eachdevice within a group before making use of the group as a whole.This may change in the future if group usage becomes more pervasiveacross both DMA and IOMMU ops.Groups intentionally do not provide a mechanism for driver lockingor otherwise manipulating driver matching/probing of devices withinthe group. Such interfaces are generic to devices and beyond thescope of IOMMU groups. If implemented, user level providers haveready access via iommu_group_for_each_dev and group notifiers.iommu_device_group() is removed here as it has no users. Thereplacement is: group = iommu_group_get(dev); id = iommu_group_id(group); iommu_group_put(group);AMD-Vi & Intel VT-d support re-added in following patches.Signed-off-by: Alex Williamson Acked-by: Benjamin Herrenschmidt Signed-off-by: Joerg Roedel List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-iommu_groups