kernel/linux.git/drivers/iommu/amd/init.c, branch v6.6.142

iommu/amd: serialize sequence allocation under concurrent TLB invalidations

2026-05-17T15:13:35+00:00

commit 9e249c48412828e807afddc21527eb734dc9bd3d upstream. With concurrent TLB invalidations, completion wait randomly gets timed out because cmd_sem_val was incremented outside the IOMMU spinlock, allowing CMD_COMPL_WAIT commands to be queued out of sequence and breaking the ordering assumption in wait_on_sem(). Move the cmd_sem_val increment under iommu->lock so completion sequence allocation is serialized with command queuing. And remove the unnecessary return. Fixes: d2a0cac10597 ("iommu/amd: move wait_on_sem() out of spinlock") Tested-by: Srikanth Aithal Reported-by: Srikanth Aithal Signed-off-by: Ankit Soni Reviewed-by: Vasant Hegde Signed-off-by: Joerg Roedel [Salvatore Bonaccorso: Backport to v6.12.y where f32fe7cb0198 ("iommu/amd: Add support to remap/unmap IOMMU buffers for kdump") is not present] Signed-off-by: Salvatore Bonaccorso Signed-off-by: Sasha Levin

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

2026-01-11T14:22:33+00:00

This reverts commit 44a764aec64b3f3235b9cbac2525222f69685418 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: Fix pci_segment memleak in alloc_pci_segment()

2026-01-11T14:22:10+00:00

commit 75ba146c2674ba49ed8a222c67f9abfb4a4f2a4f upstream. Fix a memory leak of struct amd_iommu_pci_segment in alloc_pci_segment() when system memory (or contiguous memory) is insufficient. Fixes: 04230c119930 ("iommu/amd: Introduce per PCI segment device table") Fixes: eda797a27795 ("iommu/amd: Introduce per PCI segment rlookup table") Fixes: 99fc4ac3d297 ("iommu/amd: Introduce per PCI segment alias_table") Cc: stable@vger.kernel.org Signed-off-by: Jinhui Guo Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

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

2025-11-24T09:29:34+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

2025-08-28T14:28:48+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

2025-05-09T07:43:52+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

2024-06-21T12:38:30+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: Mark interrupt as managed

2024-03-26T22:19:30+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: Enable PPR/GA interrupt after interrupt handler setup

2023-07-14T14:21:42+00:00

Current code enables PPR and GA interrupts before setting up the interrupt handler (in state_next()). Make sure interrupt handler is in place before enabling these interrupt. amd_iommu_enable_interrupts() gets called in normal boot, kdump as well as in suspend/resume path. Hence moving interrupt enablement to this function works fine. Reviewed-by: Suravee Suthikulpanit Signed-off-by: Vasant Hegde Reviewed-by: Jerry Snitselaar Link: https://lore.kernel.org/r/20230628054554.6131-4-vasant.hegde@amd.com Signed-off-by: Joerg Roedel

iommu/amd: Consolidate PPR log enablement

2023-07-14T14:21:41+00:00

Move PPR log interrupt bit setting to iommu_enable_ppr_log(). Also rearrange iommu_enable_ppr_log() such that PPREn bit is enabled before enabling PPRLog and PPRInt bits. So that when PPRLog bit is set it will clear the PPRLogOverflow bit and sets the PPRLogRun bit in the IOMMU Status Register [MMIO Offset 2020h]. Reviewed-by: Suravee Suthikulpanit Signed-off-by: Vasant Hegde Reviewed-by: Jerry Snitselaar Link: https://lore.kernel.org/r/20230628054554.6131-3-vasant.hegde@amd.com Signed-off-by: Joerg Roedel