kernel/linux.git/arch/powerpc, branch v7.0-rc7

powerpc/powernv/iommu: iommu incorrectly bypass DMA APIs

2026-04-01T16:38:55+00:00

In a PowerNV environment, for devices that supports DMA mask less than 64 bit but larger than 32 bits, iommu is incorrectly bypassing DMA APIs while allocating and mapping buffers for DMA operations. Devices are failing with ENOMEN during probe with the following messages amdgpu 0000:01:00.0: [drm] Detected VRAM RAM=4096M, BAR=4096M amdgpu 0000:01:00.0: [drm] RAM width 128bits GDDR5 amdgpu 0000:01:00.0: iommu: 64-bit OK but direct DMA is limited by 0 amdgpu 0000:01:00.0: dma_iommu_get_required_mask: returning bypass mask 0xfffffffffffffff amdgpu 0000:01:00.0: 4096M of VRAM memory ready amdgpu 0000:01:00.0: 32570M of GTT memory ready. amdgpu 0000:01:00.0: (-12) failed to allocate kernel bo amdgpu 0000:01:00.0: [drm] Debug VRAM access will use slowpath MM access amdgpu 0000:01:00.0: [drm] GART: num cpu pages 4096, num gpu pages 65536 amdgpu 0000:01:00.0: [drm] PCIE GART of 256M enabled (table at 0x000000F4FFF80000). amdgpu 0000:01:00.0: (-12) failed to allocate kernel bo amdgpu 0000:01:00.0: (-12) create WB bo failed amdgpu 0000:01:00.0: amdgpu_device_wb_init failed -12 amdgpu 0000:01:00.0: amdgpu_device_ip_init failed amdgpu 0000:01:00.0: Fatal error during GPU init amdgpu 0000:01:00.0: finishing device. amdgpu 0000:01:00.0: probe with driver amdgpu failed with error -12 amdgpu 0000:01:00.0: ttm finalized Fixes: 1471c517cf7d ("powerpc/iommu: bypass DMA APIs for coherent allocations for pre-mapped memory") Suggested-by: Ritesh Harjani (IBM) Reviewed-by: Ritesh Harjani (IBM) Reported-by: Dan Horák Closes: https://gitlab.freedesktop.org/drm/amd/-/work_items/5039 Tested-by: Dan Horak Closes: https://lore.kernel.org/linuxppc-dev/20260313142351.609bc4c3efe1184f64ca5f44@danny.cz/ Signed-off-by: Gaurav Batra Closes: https://lore.kernel.org/linuxppc-dev/20260313142351.609bc4c3efe1184f64ca5f44@danny.cz/ [Maddy: Fixed tags] Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260331223022.47488-1-gbatra@linux.ibm.com

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2026-03-15T19:22:10+00:00

Pull kvm fixes from Paolo Bonzini: "Quite a large pull request, partly due to skipping last week and therefore having material from ~all submaintainers in this one. About a fourth of it is a new selftest, and a couple more changes are large in number of files touched (fixing a -Wflex-array-member-not-at-end compiler warning) or lines changed (reformatting of a table in the API documentation, thanks rST). But who am I kidding---it's a lot of commits and there are a lot of bugs being fixed here, some of them on the nastier side like the RISC-V ones. ARM: - Correctly handle deactivation of interrupts that were activated from LRs. Since EOIcount only denotes deactivation of interrupts that are not present in an LR, start EOIcount deactivation walk *after* the last irq that made it into an LR - Avoid calling into the stubs to probe for ICH_VTR_EL2.TDS when pKVM is already enabled -- not only thhis isn't possible (pKVM will reject the call), but it is also useless: this can only happen for a CPU that has already booted once, and the capability will not change - Fix a couple of low-severity bugs in our S2 fault handling path, affecting the recently introduced LS64 handling and the even more esoteric handling of hwpoison in a nested context - Address yet another syzkaller finding in the vgic initialisation, where we would end-up destroying an uninitialised vgic with nasty consequences - Address an annoying case of pKVM failing to boot when some of the memblock regions that the host is faulting in are not page-aligned - Inject some sanity in the NV stage-2 walker by checking the limits against the advertised PA size, and correctly report the resulting faults PPC: - Fix a PPC e500 build error due to a long-standing wart that was exposed by the recent conversion to kmalloc_obj(); rip out all the ugliness that led to the wart RISC-V: - Prevent speculative out-of-bounds access using array_index_nospec() in APLIC interrupt handling, ONE_REG regiser access, AIA CSR access, float register access, and PMU counter access - Fix potential use-after-free issues in kvm_riscv_gstage_get_leaf(), kvm_riscv_aia_aplic_has_attr(), and kvm_riscv_aia_imsic_has_attr() - Fix potential null pointer dereference in kvm_riscv_vcpu_aia_rmw_topei() - Fix off-by-one array access in SBI PMU - Skip THP support check during dirty logging - Fix error code returned for Smstateen and Ssaia ONE_REG interface - Check host Ssaia extension when creating AIA irqchip x86: - Fix cases where CPUID mitigation features were incorrectly marked as available whenever the kernel used scattered feature words for them - Validate _all_ GVAs, rather than just the first GVA, when processing a range of GVAs for Hyper-V's TLB flush hypercalls - Fix a brown paper bug in add_atomic_switch_msr() - Use hlist_for_each_entry_srcu() when traversing mask_notifier_list, to fix a lockdep warning; KVM doesn't hold RCU, just irq_srcu - Ensure AVIC VMCB fields are initialized if the VM has an in-kernel local APIC (and AVIC is enabled at the module level) - Update CR8 write interception when AVIC is (de)activated, to fix a bug where the guest can run in perpetuity with the CR8 intercept enabled - Add a quirk to skip the consistency check on FREEZE_IN_SMM, i.e. to allow L1 hypervisors to set FREEZE_IN_SMM. This reverts (by default) an unintentional tightening of userspace ABI in 6.17, and provides some amount of backwards compatibility with hypervisors who want to freeze PMCs on VM-Entry - Validate the VMCS/VMCB on return to a nested guest from SMM, because either userspace or the guest could stash invalid values in memory and trigger the processor's consistency checks Generic: - Remove a subtle pseudo-overlay of kvm_stats_desc, which, aside from being unnecessary and confusing, triggered compiler warnings due to -Wflex-array-member-not-at-end - Document that vcpu->mutex is take outside of kvm->slots_lock and kvm->slots_arch_lock, which is intentional and desirable despite being rather unintuitive Selftests: - Increase the maximum number of NUMA nodes in the guest_memfd selftest to 64 (from 8)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (43 commits) KVM: selftests: Verify SEV+ guests can read and write EFER, CR0, CR4, and CR8 Documentation: kvm: fix formatting of the quirks table KVM: x86: clarify leave_smm() return value selftests: kvm: add a test that VMX validates controls on RSM selftests: kvm: extract common functionality out of smm_test.c KVM: SVM: check validity of VMCB controls when returning from SMM KVM: VMX: check validity of VMCS controls when returning from SMM KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated KVM: SVM: Initialize AVIC VMCB fields if AVIC is enabled with in-kernel APIC KVM: x86: Introduce KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM KVM: x86: Fix SRCU list traversal in kvm_fire_mask_notifiers() KVM: VMX: Fix a wrong MSR update in add_atomic_switch_msr() KVM: x86: hyper-v: Validate all GVAs during PV TLB flush KVM: x86: synthesize CPUID bits only if CPU capability is set KVM: PPC: e500: Rip out "struct tlbe_ref" KVM: PPC: e500: Fix build error due to using kmalloc_obj() with wrong type KVM: selftests: Increase 'maxnode' for guest_memfd tests KVM: arm64: pkvm: Don't reprobe for ICH_VTR_EL2.TDS on CPU hotplug KVM: arm64: vgic: Pick EOIcount deactivations from AP-list tail KVM: arm64: Remove the redundant ISB in __kvm_at_s1e2() ...

Merge tag 'powerpc-7.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2026-03-15T18:36:11+00:00

Pull powerpc fixes from Madhavan Srinivasan: - Fix KUAP warning in VMX usercopy path - Fix lockdep warning during PCI enumeration - Fix to move CMA reservations to arch_mm_preinit - Fix to check current->mm is alive before getting user callchain Thanks to Aboorva Devarajan, Christophe Leroy (CS GROUP), Dan Horák, Nicolin Chen, Nilay Shroff, Qiao Zhao, Ritesh Harjani (IBM), Saket Kumar Bhaskar, Sayali Patil, Shrikanth Hegde, Venkat Rao Bagalkote, and Viktor Malik. * tag 'powerpc-7.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/iommu: fix lockdep warning during PCI enumeration powerpc/selftests/copyloops: extend selftest to exercise __copy_tofrom_user_power7_vmx powerpc: fix KUAP warning in VMX usercopy path powerpc, perf: Check that current->mm is alive before getting user callchain powerpc/mem: Move CMA reservations to arch_mm_preinit

powerpc/iommu: fix lockdep warning during PCI enumeration

2026-03-13T06:43:35+00:00

Commit a75b2be249d6 ("iommu: Add iommu_driver_get_domain_for_dev() helper") introduced iommu_driver_get_domain_for_dev() for driver code paths that hold iommu_group->mutex while attaching a device to an IOMMU domain. The same commit also added a lockdep assertion in iommu_get_domain_for_dev() to ensure that callers do not hold iommu_group->mutex when invoking it. On powerpc platforms, when PCI device ownership is switched from BLOCKED to the PLATFORM domain, the attach callback spapr_tce_platform_iommu_attach_dev() still calls iommu_get_domain_for_dev(). This happens while iommu_group->mutex is held during domain switching, which triggers the lockdep warning below during PCI enumeration: WARNING: drivers/iommu/iommu.c:2252 at iommu_get_domain_for_dev+0x38/0x80, CPU#2: swapper/0/1 Modules linked in: CPU: 2 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc2+ #35 PREEMPT Hardware name: IBM,9105-22A Power11 (architected) 0x820200 0xf000007 of:IBM,FW1120.00 (RB1120_115) hv:phyp pSeries NIP: c000000000c244c4 LR: c00000000005b5a4 CTR: c00000000005b578 REGS: c00000000a7bf280 TRAP: 0700 Not tainted (7.0.0-rc2+) MSR: 8000000002029033 CR: 22004422 XER: 0000000a CFAR: c000000000c24508 IRQMASK: 0 GPR00: c00000000005b5a4 c00000000a7bf520 c000000001dc8100 0000000000000001 GPR04: c00000000f972f10 0000000000000000 0000000000000000 0000000000000001 GPR08: 0000001ffbc60000 0000000000000001 0000000000000000 0000000000000000 GPR12: c00000000005b578 c000001fffffe480 c000000000011618 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: ffffffffffffefff 0000000000000000 c000000002d30eb0 0000000000000001 GPR24: c0000000017881f8 0000000000000000 0000000000000001 c00000000f972e00 GPR28: c00000000bbba0d0 0000000000000000 c00000000bbba0d0 c00000000f972e00 NIP [c000000000c244c4] iommu_get_domain_for_dev+0x38/0x80 LR [c00000000005b5a4] spapr_tce_platform_iommu_attach_dev+0x2c/0x98 Call Trace: iommu_get_domain_for_dev+0x68/0x80 (unreliable) spapr_tce_platform_iommu_attach_dev+0x2c/0x98 __iommu_attach_device+0x44/0x220 __iommu_device_set_domain+0xf4/0x194 __iommu_group_set_domain_internal+0xec/0x228 iommu_setup_default_domain+0x5f4/0x6a4 __iommu_probe_device+0x674/0x724 iommu_probe_device+0x50/0xb4 iommu_add_device+0x48/0x198 pci_dma_dev_setup_pSeriesLP+0x198/0x4f0 pcibios_bus_add_device+0x80/0x464 pci_bus_add_device+0x40/0x100 pci_bus_add_devices+0x54/0xb0 pcibios_init+0xd8/0x140 do_one_initcall+0x8c/0x598 kernel_init_freeable+0x3ec/0x850 kernel_init+0x34/0x270 ret_from_kernel_user_thread+0x14/0x1c Fix this by using iommu_driver_get_domain_for_dev() instead of iommu_get_domain_for_dev() in spapr_tce_platform_iommu_attach_dev(), which is the appropriate helper for callers holding the group mutex. Cc: stable@vger.kernel.org Fixes: a75b2be249d6 ("iommu: Add iommu_driver_get_domain_for_dev() helper") Closes: https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d5c834ff-4c95-44dd-8bef-57242d63aeee@linux.ibm.com/ Signed-off-by: Nilay Shroff Reviewed-by: Nicolin Chen Tested-by: Venkat Rao Bagalkote [Maddy: Added Closes, tested and reviewed by tags] Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260310082129.3630996-1-nilay@linux.ibm.com

powerpc: fix KUAP warning in VMX usercopy path

2026-03-12T05:33:47+00:00

On powerpc with PREEMPT_FULL or PREEMPT_LAZY and function tracing enabled, KUAP warnings can be triggered from the VMX usercopy path under memory stress workloads. KUAP requires that no subfunctions are called once userspace access has been enabled. The existing VMX copy implementation violates this requirement by invoking enter_vmx_usercopy() from the assembly path after userspace access has already been enabled. If preemption occurs in this window, the AMR state may not be preserved correctly, leading to unexpected userspace access state and resulting in KUAP warnings. Fix this by restructuring the VMX usercopy flow so that VMX selection and VMX state management are centralized in raw_copy_tofrom_user(), which is invoked by the raw_copy_{to,from,in}_user() wrappers. The new flow is: - raw_copy_{to,from,in}_user() calls raw_copy_tofrom_user() - raw_copy_tofrom_user() decides whether to use the VMX path based on size and CPU capability - Call enter_vmx_usercopy() before enabling userspace access - Enable userspace access as per the copy direction and perform the VMX copy - Disable userspace access as per the copy direction - Call exit_vmx_usercopy() - Fall back to the base copy routine if the VMX copy faults With this change, the VMX assembly routines no longer perform VMX state management or call helper functions; they only implement the copy operations. The previous feature-section based VMX selection inside __copy_tofrom_user_power7() is removed, and a dedicated __copy_tofrom_user_power7_vmx() entry point is introduced. This ensures correct KUAP ordering, avoids subfunction calls while KUAP is unlocked, and eliminates the warnings while preserving the VMX fast path. Fixes: de78a9c42a79 ("powerpc: Add a framework for Kernel Userspace Access Protection") Reported-by: Shrikanth Hegde Closes: https://lore.kernel.org/all/20260109064917.777587-2-sshegde@linux.ibm.com/ Suggested-by: Christophe Leroy (CS GROUP) Reviewed-by: Christophe Leroy (CS GROUP) Co-developed-by: Aboorva Devarajan Signed-off-by: Aboorva Devarajan Signed-off-by: Sayali Patil Tested-by: Shrikanth Hegde Tested-by: Venkat Rao Bagalkote Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260304122201.153049-1-sayalip@linux.ibm.com

powerpc, perf: Check that current->mm is alive before getting user callchain

2026-03-12T05:32:55+00:00

It may happen that mm is already released, which leads to kernel panic. This adds the NULL check for current->mm, similarly to commit 20afc60f892d ("x86, perf: Check that current->mm is alive before getting user callchain"). I was getting this panic when running a profiling BPF program (profile.py from bcc-tools): [26215.051935] Kernel attempted to read user page (588) - exploit attempt? (uid: 0) [26215.051950] BUG: Kernel NULL pointer dereference on read at 0x00000588 [26215.051952] Faulting instruction address: 0xc00000000020fac0 [26215.051957] Oops: Kernel access of bad area, sig: 11 [#1] [...] [26215.052049] Call Trace: [26215.052050] [c000000061da6d30] [c00000000020fc10] perf_callchain_user_64+0x2d0/0x490 (unreliable) [26215.052054] [c000000061da6dc0] [c00000000020f92c] perf_callchain_user+0x1c/0x30 [26215.052057] [c000000061da6de0] [c0000000005ab2a0] get_perf_callchain+0x100/0x360 [26215.052063] [c000000061da6e70] [c000000000573bc8] bpf_get_stackid+0x88/0xf0 [26215.052067] [c000000061da6ea0] [c008000000042258] bpf_prog_16d4ab9ab662f669_do_perf_event+0xf8/0x274 [...] In addition, move storing the top-level stack entry to generic perf_callchain_user to make sure the top-evel entry is always captured, even if current->mm is NULL. Fixes: 20002ded4d93 ("perf_counter: powerpc: Add callchain support") Signed-off-by: Viktor Malik Tested-by: Qiao Zhao Tested-by: Venkat Rao Bagalkote Reviewed-by: Saket Kumar Bhaskar [Maddy: fixed message to avoid checkpatch format style error] Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260309144045.169427-1-vmalik@redhat.com

powerpc/mem: Move CMA reservations to arch_mm_preinit

2026-03-12T05:27:31+00:00

commit 4267739cabb8 ("arch, mm: consolidate initialization of SPARSE memory model"), changed the initialization order of "pageblock_order" from... start_kernel() - setup_arch() - initmem_init() - sparse_init() - set_pageblock_order(); // this sets the pageblock_order - xxx_cma_reserve(); to... start_kernel() - setup_arch() - xxx_cma_reserve(); - mm_core_init_early() - free_area_init() - sparse_init() - set_pageblock_order() // this sets the pageblock_order. So this means, pageblock_order is not initialized before these cma reservation function calls, hence we are seeing CMA failures like... [ 0.000000] kvm_cma_reserve: reserving 3276 MiB for global area [ 0.000000] cma: pageblock_order not yet initialized. Called during early boot? [ 0.000000] cma: Failed to reserve 3276 MiB .... [ 0.000000][ T0] cma: pageblock_order not yet initialized. Called during early boot? [ 0.000000][ T0] cma: Failed to reserve 1024 MiB This patch moves these CMA reservations to arch_mm_preinit() which happens in mm_core_init() (which happens after pageblock_order is initialized), but before the memblock moves the free memory to buddy. Fixes: 4267739cabb8 ("arch, mm: consolidate initialization of SPARSE memory model") Suggested-by: Mike Rapoport Reported-and-tested-by: Sourabh Jain Closes: https://lore.kernel.org/linuxppc-dev/4c338a29-d190-44f3-8874-6cfa0a031f0b@linux.ibm.com/ Signed-off-by: Ritesh Harjani (IBM) Tested-by: Dan Horák Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/6e532cf0db5be99afbe20eed699163d5e86cd71f.1772303986.git.ritesh.list@gmail.com

KVM: PPC: e500: Rip out "struct tlbe_ref"

2026-03-11T17:41:10+00:00

Complete the ~13 year journey started by commit 47bf379742bf ("kvm/ppc/e500: eliminate tlb_refs"), and actually remove "struct tlbe_ref". No functional change intended (verified disassembly of e500_mmu.o and e500_mmu_host.o is identical before and after). Link: https://patch.msgid.link/20260303190339.974325-3-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini

KVM: PPC: e500: Fix build error due to using kmalloc_obj() with wrong type

2026-03-11T17:41:10+00:00

Fix a build error in kvmppc_e500_tlb_init() that was introduced by the conversion to use kzalloc_objs(), as KVM confusingly uses the size of the structure that is one and only field in tlbe_priv: arch/powerpc/kvm/e500_mmu.c:923:33: error: assignment to 'struct tlbe_priv *' from incompatible pointer type 'struct tlbe_ref *' [-Wincompatible-pointer-types] 923 | vcpu_e500->gtlb_priv[0] = kzalloc_objs(struct tlbe_ref, | ^ KVM has been flawed since commit 0164c0f0c404 ("KVM: PPC: e500: clear up confusion between host and guest entries"), but the issue went unnoticed until kmalloc_obj() came along and enforced types, as "struct tlbe_priv" was just a wrapper of "struct tlbe_ref" (why on earth the two ever existed separately...). Fixes: 69050f8d6d07 ("treewide: Replace kmalloc with kmalloc_obj for non-scalar types") Cc: Kees Cook Reviewed-by: Christophe Leroy (CS GROUP) Link: https://patch.msgid.link/20260303190339.974325-2-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini

Merge tag 'kvm-x86-generic-7.0-rc3' of https://github.com/kvm-x86/linux into HEAD

2026-03-11T17:01:55+00:00

KVM generic changes for 7.0 - Remove a subtle pseudo-overlay of kvm_stats_desc, which, aside from being unnecessary and confusing, triggered compiler warnings due to -Wflex-array-member-not-at-end. - Document that vcpu->mutex is take outside of kvm->slots_lock and kvm->slots_arch_lock, which is intentional and desirable despite being rather unintuitive.