kernel/linux.git/drivers/iommu/amd/init.c, branch v5.15.208

Revert "iommu/amd: Skip enabling command/event buffers for kdump"

2026-01-19T12:10:13+00:00

This reverts commit bb8f9de71c9bd442ec5e1d52ce830428860892f0 which is commit 9be15fbfc6c5c89c22cf6e209f66ea43ee0e58bb upstream. This causes problems in older kernel trees as SNP host kdump is not supported in them, so drop it from the stable branches. Reported-by: Ashish Kalra Link: https://lore.kernel.org/r/dacdff7f-0606-4ed5-b056-2de564404d51@amd.com Cc: Vasant Hegde Cc: Sairaj Kodilkar Cc: Joerg Roedel Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

iommu/amd: Skip enabling command/event buffers for kdump

2025-12-06T21:09:21+00:00

[ Upstream commit 9be15fbfc6c5c89c22cf6e209f66ea43ee0e58bb ] After a panic if SNP is enabled in the previous kernel then the kdump kernel boots with IOMMU SNP enforcement still enabled. IOMMU command buffers and event buffer registers remain locked and exclusive to the previous kernel. Attempts to enable command and event buffers in the kdump kernel will fail, as hardware ignores writes to the locked MMIO registers as per AMD IOMMU spec Section 2.12.2.1. Skip enabling command buffers and event buffers for kdump boot as they are already enabled in the previous kernel. Reviewed-by: Vasant Hegde Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Link: https://lore.kernel.org/r/576445eb4f168b467b0fc789079b650ca7c5b037.1756157913.git.ashish.kalra@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Avoid stack buffer overflow from kernel cmdline

2025-08-28T14:24:37+00:00

[ Upstream commit 8503d0fcb1086a7cfe26df67ca4bd9bd9e99bdec ] While the kernel command line is considered trusted in most environments, avoid writing 1 byte past the end of "acpiid" if the "str" argument is maximum length. Reported-by: Simcha Kosman Closes: https://lore.kernel.org/all/AS8P193MB2271C4B24BCEDA31830F37AE84A52@AS8P193MB2271.EURP193.PROD.OUTLOOK.COM Fixes: b6b26d86c61c ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter") Signed-off-by: Kees Cook Reviewed-by: Ankit Soni Link: https://lore.kernel.org/r/20250804154023.work.970-kees@kernel.org Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Fix potential buffer overflow in parse_ivrs_acpihid

2025-05-09T07:39:37+00:00

commit 8dee308e4c01dea48fc104d37f92d5b58c50b96c upstream. There is a string parsing logic error which can lead to an overflow of hid or uid buffers. Comparing ACPIID_LEN against a total string length doesn't take into account the lengths of individual hid and uid buffers so the check is insufficient in some cases. For example if the length of hid string is 4 and the length of the uid string is 260, the length of str will be equal to ACPIID_LEN + 1 but uid string will overflow uid buffer which size is 256. The same applies to the hid string with length 13 and uid string with length 250. Check the length of hid and uid strings separately to prevent buffer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: ca3bf5d47cec ("iommu/amd: Introduces ivrs_acpihid kernel parameter") Cc: stable@vger.kernel.org Signed-off-by: Pavel Paklov Link: https://lore.kernel.org/r/20250325092259.392844-1-Pavel.Paklov@cyberprotect.ru Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/amd: Fix sysfs leak in iommu init

2024-07-05T07:14:17+00:00

[ Upstream commit a295ec52c8624883885396fde7b4df1a179627c3 ] During the iommu initialization, iommu_init_pci() adds sysfs nodes. However, these nodes aren't remove in free_iommu_resources() subsequently. Fixes: 39ab9555c241 ("iommu: Add sysfs bindings for struct iommu_device") Signed-off-by: Kun(llfl) Reviewed-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/c8e0d11c6ab1ee48299c288009cf9c5dae07b42d.1715215003.git.llfl@linux.alibaba.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Introduce pci segment structure

2024-07-05T07:14:16+00:00

[ Upstream commit 404ec4e4c169fb64da6b2a38b471c13ac0897c76 ] Newer AMD systems can support multiple PCI segments, where each segment contains one or more IOMMU instances. However, an IOMMU instance can only support a single PCI segment. Current code assumes that system contains only one pci segment (segment 0) and creates global data structures such as device table, rlookup table, etc. Introducing per PCI segment data structure, which contains segment specific data structures. This will eventually replace the global data structures. Also update `amd_iommu->pci_seg` variable to point to PCI segment structure instead of PCI segment ID. Co-developed-by: Suravee Suthikulpanit Signed-off-by: Suravee Suthikulpanit Signed-off-by: Vasant Hegde Link: https://lore.kernel.org/r/20220706113825.25582-3-vasant.hegde@amd.com Signed-off-by: Joerg Roedel Stable-dep-of: a295ec52c862 ("iommu/amd: Fix sysfs leak in iommu init") Signed-off-by: Sasha Levin

iommu/amd: Mark interrupt as managed

2024-03-26T22:21:19+00:00

[ Upstream commit 0feda94c868d396fac3b3cb14089d2d989a07c72 ] On many systems that have an AMD IOMMU the following sequence of warnings is observed during bootup. ``` pci 0000:00:00.2 can't derive routing for PCI INT A pci 0000:00:00.2: PCI INT A: not connected ``` This series of events happens because of the IOMMU initialization sequence order and the lack of _PRT entries for the IOMMU. During initialization the IOMMU driver first enables the PCI device using pci_enable_device(). This will call acpi_pci_irq_enable() which will check if the interrupt is declared in a PCI routing table (_PRT) entry. According to the PCI spec [1] these routing entries are only required under PCI root bridges: The _PRT object is required under all PCI root bridges The IOMMU is directly connected to the root complex, so there is no parent bridge to look for a _PRT entry. The first warning is emitted since no entry could be found in the hierarchy. The second warning is then emitted because the interrupt hasn't yet been configured to any value. The pin was configured in pci_read_irq() but the byte in PCI_INTERRUPT_LINE return 0xff which means "Unknown". After that sequence of events pci_enable_msi() is called and this will allocate an interrupt. That is both of these warnings are totally harmless because the IOMMU uses MSI for interrupts. To avoid even trying to probe for a _PRT entry mark the IOMMU as IRQ managed. This avoids both warnings. Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/06_Device_Configuration/Device_Configuration.html?highlight=_prt#prt-pci-routing-table [1] Signed-off-by: Mario Limonciello Fixes: cffe0a2b5a34 ("x86, irq: Keep balance of IOAPIC pin reference count") Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20240122233400.1802-1-mario.limonciello@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter

2023-03-17T07:48:58+00:00

[ Upstream commit b6b26d86c61c441144c72f842f7469bb686e1211 ] The 'acpiid' buffer in the parse_ivrs_acpihid function may overflow, because the string specifier in the format string sscanf() has no width limitation. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE. Fixes: ca3bf5d47cec ("iommu/amd: Introduces ivrs_acpihid kernel parameter") Cc: stable@vger.kernel.org Signed-off-by: Ilia.Gavrilov Reviewed-by: Kim Phillips Link: https://lore.kernel.org/r/20230202082719.1513849-1-Ilia.Gavrilov@infotecs.ru Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Fix ill-formed ivrs_ioapic, ivrs_hpet and ivrs_acpihid options

2023-03-17T07:48:58+00:00

[ Upstream commit 1198d2316dc4265a97d0e8445a22c7a6d17580a4 ] Currently, these options cause the following libkmod error: libkmod: ERROR ../libkmod/libkmod-config.c:489 kcmdline_parse_result: \ Ignoring bad option on kernel command line while parsing module \ name: 'ivrs_xxxx[XX:XX' Fix by introducing a new parameter format for these options and throw a warning for the deprecated format. Users are still allowed to omit the PCI Segment if zero. Adding a Link: to the reason why we're modding the syntax parsing in the driver and not in libkmod. Fixes: ca3bf5d47cec ("iommu/amd: Introduces ivrs_acpihid kernel parameter") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-modules/20200310082308.14318-2-lucas.demarchi@intel.com/ Reported-by: Kim Phillips Co-developed-by: Suravee Suthikulpanit Signed-off-by: Suravee Suthikulpanit Signed-off-by: Kim Phillips Link: https://lore.kernel.org/r/20220919155638.391481-2-kim.phillips@amd.com Signed-off-by: Joerg Roedel Stable-dep-of: b6b26d86c61c ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter") Signed-off-by: Sasha Levin

iommu/amd: Add PCI segment support for ivrs_[ioapic/hpet/acpihid] commands

2023-03-17T07:48:58+00:00

[ Upstream commit bbe3a106580c21bc883fb0c9fa3da01534392fe8 ] By default, PCI segment is zero and can be omitted. To support system with non-zero PCI segment ID, modify the parsing functions to allow PCI segment ID. Co-developed-by: Vasant Hegde Signed-off-by: Vasant Hegde Signed-off-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/20220706113825.25582-33-vasant.hegde@amd.com Signed-off-by: Joerg Roedel Stable-dep-of: b6b26d86c61c ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter") Signed-off-by: Sasha Levin