kernel/linux.git/drivers/iommu/amd/init.c, branch v6.1.168

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

2026-01-11T14:19:27+00:00

This reverts commit f33890f95140660923003ba1e2f114dee20e691b 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()

2026-01-11T14:19:05+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

2025-12-06T21:12:22+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

2025-08-28T14:26:17+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

2025-05-09T07:41:35+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

2024-06-21T12:35:49+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

2024-03-26T22:20:36+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: Introduce Disable IRTE Caching Support

2023-08-23T15:52:21+00:00

[ Upstream commit 66419036f68a838c00cbccacd6cb2e99da6e5710 ] An Interrupt Remapping Table (IRT) stores interrupt remapping configuration for each device. In a normal operation, the AMD IOMMU caches the table to optimize subsequent data accesses. This requires the IOMMU driver to invalidate IRT whenever it updates the table. The invalidation process includes issuing an INVALIDATE_INTERRUPT_TABLE command following by a COMPLETION_WAIT command. However, there are cases in which the IRT is updated at a high rate. For example, for IOMMU AVIC, the IRTE[IsRun] bit is updated on every vcpu scheduling (i.e. amd_iommu_update_ga()). On system with large amount of vcpus and VFIO PCI pass-through devices, the invalidation process could potentially become a performance bottleneck. Introducing a new kernel boot option: amd_iommu=irtcachedis which disables IRTE caching by setting the IRTCachedis bit in each IOMMU Control register, and bypass the IRT invalidation process. Reviewed-by: Jerry Snitselaar Co-developed-by: Alejandro Jimenez Signed-off-by: Alejandro Jimenez Signed-off-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/20230530141137.14376-4-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommu/amd: Handle GALog overflows

2023-06-09T08:34:00+00:00

[ Upstream commit af47b0a24058e56e983881993752f88288ca6511 ] GALog exists to propagate interrupts into all vCPUs in the system when interrupts are marked as non running (e.g. when vCPUs aren't running). A GALog overflow happens when there's in no space in the log to record the GATag of the interrupt. So when the GALOverflow condition happens, the GALog queue is processed and the GALog is restarted, as the IOMMU manual indicates in section "2.7.4 Guest Virtual APIC Log Restart Procedure": | * Wait until MMIO Offset 2020h[GALogRun]=0b so that all request | entries are completed as circumstances allow. GALogRun must be 0b to | modify the guest virtual APIC log registers safely. | * Write MMIO Offset 0018h[GALogEn]=0b. | * As necessary, change the following values (e.g., to relocate or | resize the guest virtual APIC event log): | - the Guest Virtual APIC Log Base Address Register | [MMIO Offset 00E0h], | - the Guest Virtual APIC Log Head Pointer Register | [MMIO Offset 2040h][GALogHead], and | - the Guest Virtual APIC Log Tail Pointer Register | [MMIO Offset 2048h][GALogTail]. | * Write MMIO Offset 2020h[GALOverflow] = 1b to clear the bit (W1C). | * Write MMIO Offset 0018h[GALogEn] = 1b, and either set | MMIO Offset 0018h[GAIntEn] to enable the GA log interrupt or clear | the bit to disable it. Failing to handle the GALog overflow means that none of the VFs (in any guest) will work with IOMMU AVIC forcing the user to power cycle the host. When handling the event it resumes the GALog without resizing much like how it is done in the event handler overflow. The [MMIO Offset 2020h][GALOverflow] bit might be set in status register without the [MMIO Offset 2020h][GAInt] bit, so when deciding to poll for GA events (to clear space in the galog), also check the overflow bit. [suravee: Check for GAOverflow without GAInt, toggle CONTROL_GAINT_EN] Co-developed-by: Suravee Suthikulpanit Signed-off-by: Suravee Suthikulpanit Signed-off-by: Joao Martins Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20230419201154.83880-3-joao.m.martins@oracle.com Signed-off-by: Joerg Roedel Stable-dep-of: 8ec4e2befef1 ("iommu/amd: Fix up merge conflict resolution") Signed-off-by: Sasha Levin

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

2023-03-10T08:34:27+00:00

commit b6b26d86c61c441144c72f842f7469bb686e1211 upstream. 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: Greg Kroah-Hartman