kernel/linux.git/drivers/iommu/amd/init.c, branch v6.18.35

iommu/amd: serialize sequence allocation under concurrent TLB invalidations

2026-03-04T12:20:43+00:00

[ Upstream commit 9e249c48412828e807afddc21527eb734dc9bd3d ] 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 Signed-off-by: Sasha Levin

iommu/amd: Use core's primary handler and set IRQF_ONESHOT

2026-02-26T22:59:05+00:00

[ Upstream commit 5bfcdccb4d18d3909b7f87942be67fd6bdc00c1d ] request_threaded_irq() is invoked with a primary and a secondary handler and no flags are passed. The primary handler is the same as irq_default_primary_handler() so there is no need to have an identical copy. The lack of the IRQF_ONESHOT can be dangerous because the interrupt source is not masked while the threaded handler is active. This means, especially on LEVEL typed interrupt lines, the interrupt can fire again before the threaded handler had a chance to run. Use the default primary interrupt handler by specifying NULL and set IRQF_ONESHOT so the interrupt source is masked until the secondary handler is done. Fixes: 72fe00f01f9a3 ("x86/amd-iommu: Use threaded interupt handler") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://patch.msgid.link/20260128095540.863589-4-bigeasy@linutronix.de Signed-off-by: Sasha Levin

iommu/amd: Fix pci_segment memleak in alloc_pci_segment()

2026-01-08T09:16:55+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

amd/iommu: Preserve domain ids inside the kdump kernel

2026-01-02T11:56:54+00:00

[ Upstream commit c2e8dc1222c2136e714d5d972dce7e64924e4ed8 ] Currently AMD IOMMU driver does not reserve domain ids programmed in the DTE while reusing the device table inside kdump kernel. This can cause reallocation of these domain ids for newer domains that are created by the kdump kernel, which can lead to potential IO_PAGE_FAULTs Hence reserve these ids inside pdom_ids. Fixes: 38e5f33ee359 ("iommu/amd: Reuse device table for kdump") Signed-off-by: Sairaj Kodilkar Reported-by: Jason Gunthorpe Reviewed-by: Vasant Hegde Reviewed-by: Jason Gunthorpe Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

Merge branches 'apple/dart', 'ti/omap', 'riscv', 'intel/vt-d' and 'amd/amd-vi' into next

2025-09-26T08:03:33+00:00

iommu/amd: Fix alias device DTE setting

2025-09-13T06:11:30+00:00

Commit 7bea695ada0 restructured DTE flag handling but inadvertently changed the alias device configuration logic. This may cause incorrect DTE settings for certain devices. Add alias flag check before calling set_dev_entry_from_acpi(). Also move the device iteration loop inside the alias check to restrict execution to cases where alias devices are present. Fixes: 7bea695ada0 ("iommu/amd: Introduce struct ivhd_dte_flags to store persistent DTE flags") Cc: Suravee Suthikulpanit Signed-off-by: Vasant Hegde Signed-off-by: Joerg Roedel

iommu/amd: Fix ivrs_base memleak in early_amd_iommu_init()

2025-09-05T13:11:07+00:00

Fix a permanent ACPI table memory leak in early_amd_iommu_init() when CMPXCHG16B feature is not supported Fixes: 82582f85ed22 ("iommu/amd: Disable AMD IOMMU if CMPXCHG16B feature is not supported") Cc: stable@vger.kernel.org Signed-off-by: Zhen Ni Reviewed-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/20250822024915.673427-1-zhen.ni@easystack.cn Signed-off-by: Joerg Roedel

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

2025-09-05T12:45:17+00:00

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

iommu/amd: Reuse device table for kdump

2025-09-05T12:44:32+00:00

After a panic if SNP is enabled in the previous kernel then the kdump kernel boots with IOMMU SNP enforcement still enabled. IOMMU device table register is locked and exclusive to the previous kernel. Attempts to copy old device table from the previous kernel fails in kdump kernel as hardware ignores writes to the locked device table base address register as per AMD IOMMU spec Section 2.12.2.1. This causes the IOMMU driver (OS) and the hardware to reference different memory locations. As a result, the IOMMU hardware cannot process the command which results in repeated "Completion-Wait loop timed out" errors and a second kernel panic: "Kernel panic - not syncing: timer doesn't work through Interrupt-remapped IO-APIC". Reuse device table instead of copying device table in case of kdump boot and remove all copying device table code. Reviewed-by: Vasant Hegde Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Link: https://lore.kernel.org/r/3a31036fb2f7323e6b1a1a1921ac777e9f7bdddc.1756157913.git.ashish.kalra@amd.com Signed-off-by: Joerg Roedel

iommu/amd: Add support to remap/unmap IOMMU buffers for kdump

2025-09-05T12:44:30+00:00

After a panic if SNP is enabled in the previous kernel then the kdump kernel boots with IOMMU SNP enforcement still enabled. IOMMU completion wait buffers (CWBs), command buffers and event buffer registers remain locked and exclusive to the previous kernel. Attempts to allocate and use new buffers in the kdump kernel fail, as hardware ignores writes to the locked MMIO registers as per AMD IOMMU spec Section 2.12.2.1. This results in repeated "Completion-Wait loop timed out" errors and a second kernel panic: "Kernel panic - not syncing: timer doesn't work through Interrupt-remapped IO-APIC" The list of MMIO registers locked and which ignore writes after failed SNP shutdown are mentioned in the AMD IOMMU specifications below: Section 2.12.2.1. https://docs.amd.com/v/u/en-US/48882_3.10_PUB Reuse the pages of the previous kernel for completion wait buffers, command buffers, event buffers and memremap them during kdump boot and essentially work with an already enabled IOMMU configuration and re-using the previous kernel’s data structures. Reusing of command buffers and event buffers is now done for kdump boot irrespective of SNP being enabled during kdump. Re-use of completion wait buffers is only done when SNP is enabled as the exclusion base register is used for the completion wait buffer (CWB) address only when SNP is enabled. Reviewed-by: Vasant Hegde Tested-by: Sairaj Kodilkar Signed-off-by: Ashish Kalra Link: https://lore.kernel.org/r/ff04b381a8fe774b175c23c1a336b28bc1396511.1756157913.git.ashish.kalra@amd.com Signed-off-by: Joerg Roedel