kernel/linux.git/drivers/iommu, branch v6.13.6

iommu/vt-d: Fix suspicious RCU usage

2025-03-07T17:27:11+00:00

commit b150654f74bf0df8e6a7936d5ec51400d9ec06d8 upstream. Commit ("iommu/vt-d: Allocate DMAR fault interrupts locally") moved the call to enable_drhd_fault_handling() to a code path that does not hold any lock while traversing the drhd list. Fix it by ensuring the dmar_global_lock lock is held when traversing the drhd list. Without this fix, the following warning is triggered: ============================= WARNING: suspicious RCU usage 6.14.0-rc3 #55 Not tainted ----------------------------- drivers/iommu/intel/dmar.c:2046 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 2 locks held by cpuhp/1/23: #0: ffffffff84a67c50 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 #1: ffffffff84a6a380 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x87/0x2c0 stack backtrace: CPU: 1 UID: 0 PID: 23 Comm: cpuhp/1 Not tainted 6.14.0-rc3 #55 Call Trace: dump_stack_lvl+0xb7/0xd0 lockdep_rcu_suspicious+0x159/0x1f0 ? __pfx_enable_drhd_fault_handling+0x10/0x10 enable_drhd_fault_handling+0x151/0x180 cpuhp_invoke_callback+0x1df/0x990 cpuhp_thread_fun+0x1ea/0x2c0 smpboot_thread_fn+0x1f5/0x2e0 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0x12a/0x2d0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x4a/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Holding the lock in enable_drhd_fault_handling() triggers a lockdep splat about a possible deadlock between dmar_global_lock and cpu_hotplug_lock. This is avoided by not holding dmar_global_lock when calling iommu_device_register(), which initiates the device probe process. Fixes: d74169ceb0d2 ("iommu/vt-d: Allocate DMAR fault interrupts locally") Reported-and-tested-by: Ido Schimmel Closes: https://lore.kernel.org/linux-iommu/Zx9OwdLIc_VoQ0-a@shredder.mtl.com/ Tested-by: Breno Leitao Cc: stable@vger.kernel.org Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20250218022422.2315082-1-baolu.lu@linux.intel.com Tested-by: Ido Schimmel Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Remove device comparison in context_setup_pass_through_cb

2025-03-07T17:27:11+00:00

commit 64f792981e35e191eb619f6f2fefab76cc7d6112 upstream. Remove the device comparison check in context_setup_pass_through_cb. pci_for_each_dma_alias already makes a decision on whether the callback function should be called for a device. With the check in place it will fail to create context entries for aliases as it walks up to the root bus. Fixes: 2031c469f816 ("iommu/vt-d: Add support for static identity domain") Closes: https://lore.kernel.org/linux-iommu/82499eb6-00b7-4f83-879a-e97b4144f576@linux.intel.com/ Cc: stable@vger.kernel.org Signed-off-by: Jerry Snitselaar Link: https://lore.kernel.org/r/20250224180316.140123-1-jsnitsel@redhat.com Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu: Fix potential memory leak in iopf_queue_remove_device()

2025-02-21T13:11:08+00:00

commit 9759ae2cee7cd42b95f1c48aa3749bd02b5ddb08 upstream. The iopf_queue_remove_device() helper removes a device from the per-iommu iopf queue when PRI is disabled on the device. It responds to all outstanding iopf's with an IOMMU_PAGE_RESP_INVALID code and detaches the device from the queue. However, it fails to release the group structure that represents a group of iopf's awaiting for a response after responding to the hardware. This can cause a memory leak if iopf_queue_remove_device() is called with pending iopf's. Fix it by calling iopf_free_group() after the iopf group is responded. Fixes: 199112327135 ("iommu: Track iopf group instead of last fault") Cc: stable@vger.kernel.org Suggested-by: Kevin Tian Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20250117055800.782462-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Make intel_iommu_drain_pasid_prq() cover faults for RID

2025-02-21T13:11:08+00:00

commit add43c4fbc92f8b48c1acd64e953af3b1be4cd9c upstream. This driver supports page faults on PCI RID since commit <9f831c16c69e> ("iommu/vt-d: Remove the pasid present check in prq_event_thread") by allowing the reporting of page faults with the pasid_present field cleared to the upper layer for further handling. The fundamental assumption here is that the detach or replace operations act as a fence for page faults. This implies that all pending page faults associated with a specific RID or PASID are flushed when a domain is detached or replaced from a device RID or PASID. However, the intel_iommu_drain_pasid_prq() helper does not correctly handle faults for RID. This leads to faults potentially remaining pending in the iommu hardware queue even after the domain is detached, thereby violating the aforementioned assumption. Fix this issue by extending intel_iommu_drain_pasid_prq() to cover faults for RID. Fixes: 9f831c16c69e ("iommu/vt-d: Remove the pasid present check in prq_event_thread") Cc: stable@vger.kernel.org Suggested-by: Kevin Tian Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20250121023150.815972-1-baolu.lu@linux.intel.com Reviewed-by: Yi Liu Link: https://lore.kernel.org/r/20250211005512.985563-2-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel Signed-off-by: Greg Kroah-Hartman

iommu/amd: Expicitly enable CNTRL.EPHEn bit in resume path

2025-02-21T13:10:51+00:00

[ Upstream commit ef75966abf950c0539534effa4960caa29fb7167 ] With recent kernel, AMDGPU failed to resume after suspend on certain laptop. Sample log: ----------- Nov 14 11:52:19 Thinkbook kernel: iommu ivhd0: AMD-Vi: Event logged [ILLEGAL_DEV_TABLE_ENTRY device=0000:06:00.0 pasid=0x00000 address=0x135300000 flags=0x0080] Nov 14 11:52:19 Thinkbook kernel: AMD-Vi: DTE[0]: 7d90000000000003 Nov 14 11:52:19 Thinkbook kernel: AMD-Vi: DTE[1]: 0000100103fc0009 Nov 14 11:52:19 Thinkbook kernel: AMD-Vi: DTE[2]: 2000000117840013 Nov 14 11:52:19 Thinkbook kernel: AMD-Vi: DTE[3]: 0000000000000000 This is because in resume path, CNTRL[EPHEn] is not set. Fix this by setting CNTRL[EPHEn] to 1 in resume path if EFR[EPHSUP] is set. Note May be better approach is to save the control register in suspend path and restore it in resume path instead of trying to set indivisual bits. We will have separate patch for that. Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219499 Fixes: c4cb23111103 ("iommu/amd: Add support for enable/disable IOPF") Tested-by: Hamish McIntyre-Bhatty Signed-off-by: Vasant Hegde Link: https://lore.kernel.org/r/20250127094411.5931-1-vasant.hegde@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin

iommufd/fault: Use a separate spinlock to protect fault->deliver list

2025-02-17T10:36:45+00:00

commit 3d49020a327cd7d069059317c11df24e407ccfa3 upstream. The fault->mutex serializes the fault read()/write() fops and the iommufd_fault_auto_response_faults(), mainly for fault->response. Also, it was conveniently used to fence the fault->deliver in poll() fop and iommufd_fault_iopf_handler(). However, copy_from/to_user() may sleep if pagefaults are enabled. Thus, they could take a long time to wait for user pages to swap in, blocking iommufd_fault_iopf_handler() and its caller that is typically a shared IRQ handler of an IOMMU driver, resulting in a potential global DOS. Instead of reusing the mutex to protect the fault->deliver list, add a separate spinlock, nested under the mutex, to do the job. iommufd_fault_iopf_handler() would no longer be blocked by copy_from/to_user(). Add a free_list in iommufd_auto_response_faults(), so the spinlock can simply fence a fast list_for_each_entry_safe routine. Provide two deliver list helpers for iommufd_fault_fops_read() to use: - Fetch the first iopf_group out of the fault->deliver list - Restore an iopf_group back to the head of the fault->deliver list Lastly, move the mutex closer to the response in the fault structure, and update its kdoc accordingly. Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object") Link: https://patch.msgid.link/r/20250117192901.79491-1-nicolinc@nvidia.com Cc: stable@vger.kernel.org Suggested-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Lu Baolu Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman

iommufd/fault: Destroy response and mutex in iommufd_fault_destroy()

2025-02-17T10:36:45+00:00

commit 3f4818ec139030f425476bf8a10b616bab53a7b5 upstream. Both were missing in the initial patch. Fixes: 07838f7fd529 ("iommufd: Add iommufd fault object") Link: https://patch.msgid.link/r/bc8bb13e215af27e62ee51bdba3648dd4ed2dce3.1736923732.git.nicolinc@nvidia.com Cc: stable@vger.kernel.org Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Lu Baolu Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman

iommu/tegra241-cmdqv: Read SMMU IDR1.CMDQS instead of hardcoding

2025-02-17T10:36:45+00:00

commit e94dc6ddda8dd3770879a132d577accd2cce25f9 upstream. The hardware limitation "max=19" actually comes from SMMU Command Queue. So, it'd be more natural for tegra241-cmdqv driver to read it out rather than hardcoding it itself. This is not an issue yet for a kernel on a baremetal system, but a guest kernel setting the queue base/size in form of IPA/gPA might result in a noncontiguous queue in the physical address space, if underlying physical pages backing up the guest RAM aren't contiguous entirely: e.g. 2MB-page backed guest RAM cannot guarantee a contiguous queue if it is 8MB (capped to VCMDQ_LOG2SIZE_MAX=19). This might lead to command errors when HW does linear-read from a noncontiguous queue memory. Adding this extra IDR1.CMDQS cap (in the guest kernel) allows VMM to set SMMU's IDR1.CMDQS=17 for the case mentioned above, so a guest-level queue will be capped to maximum 2MB, ensuring a contiguous queue memory. Fixes: a3799717b881 ("iommu/tegra241-cmdqv: Fix alignment failure at max_n_shift") Reported-by: Ian Kalinowski Cc: stable@vger.kernel.org Signed-off-by: Nicolin Chen Link: https://lore.kernel.org/r/20241219051421.1850267-1-nicolinc@nvidia.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

iommufd: Fix struct iommu_hwpt_pgfault init and padding

2025-02-17T10:36:44+00:00

commit e721f619e3ec9bae08bf419c3944cf1e6966c821 upstream. The iommu_hwpt_pgfault is used to report IO page fault data to userspace, but iommufd_fault_fops_read was never zeroing its padding. This leaks the content of the kernel stack memory to userspace. Also, the iommufd uAPI requires explicit padding and use of __aligned_u64 to ensure ABI compatibility's with 32 bit. pahole result, before: struct iommu_hwpt_pgfault { __u32 flags; /* 0 4 */ __u32 dev_id; /* 4 4 */ __u32 pasid; /* 8 4 */ __u32 grpid; /* 12 4 */ __u32 perm; /* 16 4 */ /* XXX 4 bytes hole, try to pack */ __u64 addr; /* 24 8 */ __u32 length; /* 32 4 */ __u32 cookie; /* 36 4 */ /* size: 40, cachelines: 1, members: 8 */ /* sum members: 36, holes: 1, sum holes: 4 */ /* last cacheline: 40 bytes */ }; pahole result, after: struct iommu_hwpt_pgfault { __u32 flags; /* 0 4 */ __u32 dev_id; /* 4 4 */ __u32 pasid; /* 8 4 */ __u32 grpid; /* 12 4 */ __u32 perm; /* 16 4 */ __u32 __reserved; /* 20 4 */ __u64 addr __attribute__((__aligned__(8))); /* 24 8 */ __u32 length; /* 32 4 */ __u32 cookie; /* 36 4 */ /* size: 40, cachelines: 1, members: 9 */ /* forced alignments: 1 */ /* last cacheline: 40 bytes */ } __attribute__((__aligned__(8))); Fixes: c714f15860fc ("iommufd: Add fault and response message definitions") Link: https://patch.msgid.link/r/20250120195051.2450-1-nicolinc@nvidia.com Cc: stable@vger.kernel.org Reviewed-by: Jason Gunthorpe Signed-off-by: Nicolin Chen Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman

iommu/vt-d: Avoid use of NULL after WARN_ON_ONCE

2025-02-17T10:36:07+00:00

[ Upstream commit 60f030f7418d3f1d94f2fb207fe3080e1844630b ] There is a WARN_ON_ONCE to catch an unlikely situation when domain_remove_dev_pasid can't find the `pasid`. In case it nevertheless happens we must avoid using a NULL pointer. Signed-off-by: Kees Bakker Link: https://lore.kernel.org/r/20241218201048.E544818E57E@bout3.ijzerbout.nl Signed-off-by: Lu Baolu Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin