[PATCH] powerpc/pseries/iommu: DLPAR ADD of pci device doesn't completely initialize pci_controller structure
Gaurav Batra
gbatra at linux.ibm.com
Thu Feb 8 13:31:13 AEDT 2024
Hello All,
There is still some issue even after applying the patch. This is not a
complete fix. I am working on V3 of the patch. Please do not merge this
patch upstream.
Thanks,
Gaurav
On 1/10/24 4:53 PM, Gaurav Batra wrote:
> When a PCI device is Dynamically added, LPAR OOPS with NULL pointer
> exception.
>
> Complete stack is as below
>
> [ 211.239206] BUG: Kernel NULL pointer dereference on read at 0x00000030
> [ 211.239210] Faulting instruction address: 0xc0000000006bbe5c
> [ 211.239214] Oops: Kernel access of bad area, sig: 11 [#1]
> [ 211.239218] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
> [ 211.239223] Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse
> [ 211.239280] CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
> [ 211.239284] Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
> [ 211.239289] NIP: c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
> [ 211.239293] REGS: c00000009924f240 TRAP: 0300 Not tainted (6.7.0-203405+)
> [ 211.239298] MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24002220 XER: 20040006
> [ 211.239306] CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
> [ 211.239306] GPR00: c000000000a13e68 c00000009924f4e0 c0000000015a2b00 0000000000000000
> [ 211.239306] GPR04: c0000000013c5590 0000000000000000 c000000006d07970 c0000000d8f8f180
> [ 211.239306] GPR08: 00000000000006ec c0000000d8f8f180 c000000002c35d58 0000000024002228
> [ 211.239306] GPR12: c0000000000579f8 c0000003ffeb3880 0000000000000000 0000000000000000
> [ 211.239306] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 211.239306] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 211.239306] GPR24: c0000000919460c0 0000000000000000 fffffffffffff000 c0000000010088e8
> [ 211.239306] GPR28: c0000000013c5590 c000000006d07970 c0000000919460c0 c0000000919460c0
> [ 211.239354] NIP [c0000000006bbe5c] sysfs_add_link_to_group+0x34/0x94
> [ 211.239361] LR [c000000000a13e68] iommu_device_link+0x5c/0x118
> [ 211.239367] Call Trace:
> [ 211.239369] [c00000009924f4e0] [c000000000a109b8] iommu_init_device+0x26c/0x318 (unreliable)
> [ 211.239376] [c00000009924f520] [c000000000a13e68] iommu_device_link+0x5c/0x118
> [ 211.239382] [c00000009924f560] [c000000000a107f4] iommu_init_device+0xa8/0x318
> [ 211.239387] [c00000009924f5c0] [c000000000a11a08] iommu_probe_device+0xc0/0x134
> [ 211.239393] [c00000009924f600] [c000000000a11ac0] iommu_bus_notifier+0x44/0x104
> [ 211.239398] [c00000009924f640] [c00000000018dcc0] notifier_call_chain+0xb8/0x19c
> [ 211.239405] [c00000009924f6a0] [c00000000018df88] blocking_notifier_call_chain+0x64/0x98
> [ 211.239411] [c00000009924f6e0] [c000000000a250fc] bus_notify+0x50/0x7c
> [ 211.239416] [c00000009924f720] [c000000000a20838] device_add+0x640/0x918
> [ 211.239421] [c00000009924f7f0] [c0000000008f1a34] pci_device_add+0x23c/0x298
> [ 211.239427] [c00000009924f840] [c000000000077460] of_create_pci_dev+0x400/0x884
> [ 211.239432] [c00000009924f8e0] [c000000000077a08] of_scan_pci_dev+0x124/0x1b0
> [ 211.239437] [c00000009924f980] [c000000000077b0c] __of_scan_bus+0x78/0x18c
> [ 211.239442] [c00000009924fa10] [c000000000073f90] pcibios_scan_phb+0x2a4/0x3b0
> [ 211.239447] [c00000009924fad0] [c0000000001007a8] init_phb_dynamic+0xb8/0x110
> [ 211.239453] [c00000009924fb40] [c008000006920620] dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
> [ 211.239461] [c00000009924fbe0] [c008000006920d64] add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
> [ 211.239468] [c00000009924fc70] [c000000000fb4144] kobj_attr_store+0x2c/0x48
> [ 211.239473] [c00000009924fc90] [c0000000006b90e4] sysfs_kf_write+0x64/0x78
> [ 211.239479] [c00000009924fcb0] [c0000000006b7b78] kernfs_fop_write_iter+0x1b0/0x290
> [ 211.239485] [c00000009924fd00] [c0000000005b6fdc] vfs_write+0x350/0x4a0
> [ 211.239491] [c00000009924fdc0] [c0000000005b7450] ksys_write+0x84/0x140
> [ 211.239496] [c00000009924fe10] [c000000000030a04] system_call_exception+0x124/0x330
> [ 211.239502] [c00000009924fe50] [c00000000000cedc] system_call_vectored_common+0x15c/0x2ec
>
> Commit a940904443e4 ("powerpc/iommu: Add iommu_ops to report capabilities
> and allow blocking domains") broke DLPAR ADD of pci devices.
>
> The above added iommu_device structure to pci_controller. During
> system boot, pci devices are discovered and this newly added iommu_device
> structure initialized by a call to iommu_device_register().
>
> During DLPAR ADD of a PCI device, a new pci_controller structure is
> allocated but there are no calls made to iommu_device_register()
> interface.
>
> Fix would be to register iommu device during DLPAR ADD as well.
>
> Fixes: a940904443e4 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains")
> Signed-off-by: Gaurav Batra <gbatra at linux.ibm.com>
> ---
> arch/powerpc/include/asm/ppc-pci.h | 3 +++
> arch/powerpc/kernel/iommu.c | 15 +++++++++++++++
> arch/powerpc/platforms/pseries/pci_dlpar.c | 4 ++++
> 3 files changed, 22 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h
> index ce2b1b5eebdd..55a2ba36e9c4 100644
> --- a/arch/powerpc/include/asm/ppc-pci.h
> +++ b/arch/powerpc/include/asm/ppc-pci.h
> @@ -29,6 +29,9 @@ void *pci_traverse_device_nodes(struct device_node *start,
> void *(*fn)(struct device_node *, void *),
> void *data);
> extern void pci_devs_phb_init_dynamic(struct pci_controller *phb);
> +extern void pci_register_device_dynamic(struct pci_controller *phb);
> +extern void pci_unregister_device_dynamic(struct pci_controller *phb);
> +
>
> /* From rtas_pci.h */
> extern void init_pci_config_tokens (void);
> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> index ebe259bdd462..342739fe74c4 100644
> --- a/arch/powerpc/kernel/iommu.c
> +++ b/arch/powerpc/kernel/iommu.c
> @@ -1388,6 +1388,21 @@ static const struct attribute_group *spapr_tce_iommu_groups[] = {
> NULL,
> };
>
> +void pci_register_device_dynamic(struct pci_controller *phb)
> +{
> + iommu_device_sysfs_add(&phb->iommu, phb->parent,
> + spapr_tce_iommu_groups, "iommu-phb%04x",
> + phb->global_number);
> + iommu_device_register(&phb->iommu, &spapr_tce_iommu_ops,
> + phb->parent);
> +}
> +
> +void pci_unregister_device_dynamic(struct pci_controller *phb)
> +{
> + iommu_device_unregister(&phb->iommu);
> + iommu_device_sysfs_remove(&phb->iommu);
> +}
> +
> /*
> * This registers IOMMU devices of PHBs. This needs to happen
> * after core_initcall(iommu_init) + postcore_initcall(pci_driver_init) and
> diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c
> index 4ba824568119..ec70ca435b7e 100644
> --- a/arch/powerpc/platforms/pseries/pci_dlpar.c
> +++ b/arch/powerpc/platforms/pseries/pci_dlpar.c
> @@ -35,6 +35,8 @@ struct pci_controller *init_phb_dynamic(struct device_node *dn)
>
> pseries_msi_allocate_domains(phb);
>
> + pci_register_device_dynamic(phb);
> +
> /* Create EEH devices for the PHB */
> eeh_phb_pe_create(phb);
>
> @@ -76,6 +78,8 @@ int remove_phb_dynamic(struct pci_controller *phb)
> }
> }
>
> + pci_unregister_device_dynamic(phb);
> +
> pseries_msi_free_domains(phb);
>
> /* Keep a reference so phb isn't freed yet */
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