kernel.git/arch/powerpc/kernel/iommu.c, branch linux-6.1.y

powerpc/iommu: Fix notifiers being shared by PCI and VIO buses

2023-09-13T07:42:48Z

[ Upstream commit c37b6908f7b2bd24dcaaf14a180e28c9132b9c58 ] fail_iommu_setup() registers the fail_iommu_bus_notifier struct to both PCI and VIO buses. struct notifier_block is a linked list node, so this causes any notifiers later registered to either bus type to also be registered to the other since they share the same node. This causes issues in (at least) the vgaarb code, which registers a notifier for PCI buses. pci_notify() ends up being called on a vio device, converted with to_pci_dev() even though it's not a PCI device, and finally makes a bad access in vga_arbiter_add_pci_device() as discovered with KASAN: BUG: KASAN: slab-out-of-bounds in vga_arbiter_add_pci_device+0x60/0xe00 Read of size 4 at addr c000000264c26fdc by task swapper/0/1 Call Trace: dump_stack_lvl+0x1bc/0x2b8 (unreliable) print_report+0x3f4/0xc60 kasan_report+0x244/0x698 __asan_load4+0xe8/0x250 vga_arbiter_add_pci_device+0x60/0xe00 pci_notify+0x88/0x444 notifier_call_chain+0x104/0x320 blocking_notifier_call_chain+0xa0/0x140 device_add+0xac8/0x1d30 device_register+0x58/0x80 vio_register_device_node+0x9ac/0xce0 vio_bus_scan_register_devices+0xc4/0x13c __machine_initcall_pseries_vio_device_init+0x94/0xf0 do_one_initcall+0x12c/0xaa8 kernel_init_freeable+0xa48/0xba8 kernel_init+0x64/0x400 ret_from_kernel_thread+0x5c/0x64 Fix this by creating separate notifier_block structs for each bus type. Fixes: d6b9a81b2a45 ("powerpc: IOMMU fault injection") Reported-by: Nageswara R Sastry Signed-off-by: Russell Currey Tested-by: Nageswara R Sastry Reviewed-by: Andrew Donnellan [mpe: Add #ifdef to fix CONFIG_IBMVIO=n build] Signed-off-by: Michael Ellerman Link: https://msgid.link/20230322035322.328709-1-ruscur@russell.cc Signed-off-by: Sasha Levin

powerpc/iommu: DMA address offset is incorrectly calculated with 2MB TCEs

2023-05-24T16:32:52Z

commit 096339ab84f36beae0b1db25e0ce63fb3873e8b2 upstream. When DMA window is backed by 2MB TCEs, the DMA address for the mapped page should be the offset of the page relative to the 2MB TCE. The code was incorrectly setting the DMA address to the beginning of the TCE range. Mellanox driver is reporting timeout trying to ENABLE_HCA for an SR-IOV ethernet port, when DMA window is backed by 2MB TCEs. Fixes: 387273118714 ("powerps/pseries/dma: Add support for 2M IOMMU page size") Cc: stable@vger.kernel.org # v5.16+ Signed-off-by: Gaurav Batra Reviewed-by: Greg Joyce Reviewed-by: Brian King Signed-off-by: Michael Ellerman Link: https://msgid.link/20230504175913.83844-1-gbatra@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/iommu: fix memory leak with using debugfs_lookup()

2023-03-17T07:50:30Z

[ Upstream commit b505063910c134778202dfad9332dfcecb76bab3 ] When calling debugfs_lookup() the result must have dput() called on it, otherwise the memory will leak over time. To make things simpler, just call debugfs_lookup_and_remove() instead which handles all of the logic at once. Signed-off-by: Greg Kroah-Hartman Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20230202141919.2298821-1-gregkh@linuxfoundation.org Signed-off-by: Sasha Levin

powerpc/iommu: Fix iommu_table_in_use for a small default DMA window case

2022-07-28T06:22:13Z

The existing iommu_table_in_use() helper checks if the kernel is using any of TCEs. There are some reserved TCEs: 1) the very first one if DMA window starts from 0 to avoid having a zero but still valid DMA handle; 2) it_reserved_start..it_reserved_end to exclude MMIO32 window in case the default window spans across that - this is the default for the first DMA window on PowerNV. When 1) is the case and 2) is not the helper does not skip 1) and returns wrong status. This only seems occurring when passing through a PCI device to a nested guest (not something we support really well) so it has not been seen before. This fixes the bug by adding a special case for no MMIO32 reservation. Fixes: 3c33066a2190 ("powerpc/kernel/iommu: Add new iommu_table_in_use() helper") Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220714081119.3714605-1-aik@ozlabs.ru

Merge branch 'topic/ppc-kvm' into next

2022-05-19T13:10:42Z

Merge our KVM topic branch.

KVM: PPC: Book3s: Retire H_PUT_TCE/etc real mode handlers

2022-05-18T14:44:01Z

LoPAPR defines guest visible IOMMU with hypercalls to use it - H_PUT_TCE/etc. Implemented first on POWER7 where hypercalls would trap in the KVM in the real mode (with MMU off). The problem with the real mode is some memory is not available and some API usage crashed the host but enabling MMU was an expensive operation. The problems with the real mode handlers are: 1. Occasionally these cannot complete the request so the code is copied+modified to work in the virtual mode, very little is shared; 2. The real mode handlers have to be linked into vmlinux to work; 3. An exception in real mode immediately reboots the machine. If the small DMA window is used, the real mode handlers bring better performance. However since POWER8, there has always been a bigger DMA window which VMs use to map the entire VM memory to avoid calling H_PUT_TCE. Such 1:1 mapping happens once and uses H_PUT_TCE_INDIRECT (a bulk version of H_PUT_TCE) which virtual mode handler is even closer to its real mode version. On POWER9 hypercalls trap straight to the virtual mode so the real mode handlers never execute on POWER9 and later CPUs. So with the current use of the DMA windows and MMU improvements in POWER9 and later, there is no point in duplicating the code. The 32bit passed through devices may slow down but we do not have many of these in practice. For example, with this applied, a 1Gbit ethernet adapter still demostrates above 800Mbit/s of actual throughput. This removes the real mode handlers from KVM and related code from the powernv platform. This updates the list of implemented hcalls in KVM-HV as the realmode handlers are removed. This changes ABI - kvmppc_h_get_tce() moves to the KVM module and kvmppc_find_table() is static now. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220506053755.3820702-1-aik@ozlabs.ru

powerpc: Remove asm/prom.h from all files that don't need it

2022-05-08T12:15:04Z

Several files include asm/prom.h for no reason. Clean it up. Signed-off-by: Christophe Leroy [mpe: Drop change to prom_parse.c as reported by lkp@intel.com] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu

Merge tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-09-03T18:22:50Z

Pull powerpc updates from Michael Ellerman: - Convert pseries & powernv to use MSI IRQ domains. - Rework the pseries CPU numbering so that CPUs that are removed, and later re-added, are given a CPU number on the same node as previously, when possible. - Add support for a new more flexible device-tree format for specifying NUMA distances. - Convert powerpc to GENERIC_PTDUMP. - Retire sbc8548 and sbc8641d board support. - Various other small features and fixes. Thanks to Alexey Kardashevskiy, Aneesh Kumar K.V, Anton Blanchard, Cédric Le Goater, Christophe Leroy, Emmanuel Gil Peyrot, Fabiano Rosas, Fangrui Song, Finn Thain, Gautham R. Shenoy, Hari Bathini, Joel Stanley, Jordan Niethe, Kajol Jain, Laurent Dufour, Leonardo Bras, Lukas Bulwahn, Marc Zyngier, Masahiro Yamada, Michal Suchanek, Nathan Chancellor, Nicholas Piggin, Parth Shah, Paul Gortmaker, Pratik R. Sampat, Randy Dunlap, Sebastian Andrzej Siewior, Srikar Dronamraju, Wan Jiabing, Xiongwei Song, and Zheng Yongjun. * tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (154 commits) powerpc/bug: Cast to unsigned long before passing to inline asm powerpc/ptdump: Fix generic ptdump for 64-bit KVM: PPC: Fix clearing never mapped TCEs in realmode powerpc/pseries/iommu: Rename "direct window" to "dma window" powerpc/pseries/iommu: Make use of DDW for indirect mapping powerpc/pseries/iommu: Find existing DDW with given property name powerpc/pseries/iommu: Update remove_dma_window() to accept property name powerpc/pseries/iommu: Reorganize iommu_table_setparms*() with new helper powerpc/pseries/iommu: Add ddw_property_create() and refactor enable_ddw() powerpc/pseries/iommu: Allow DDW windows starting at 0x00 powerpc/pseries/iommu: Add ddw_list_new_entry() helper powerpc/pseries/iommu: Add iommu_pseries_alloc_table() helper powerpc/kernel/iommu: Add new iommu_table_in_use() helper powerpc/pseries/iommu: Replace hard-coded page shift powerpc/numa: Update cpu_cpu_map on CPU online/offline powerpc/numa: Print debug statements only when required powerpc/numa: convert printk to pr_xxx powerpc/numa: Drop dbg in favour of pr_debug powerpc/smp: Enable CACHE domain for shared processor powerpc/smp: Update cpu_core_map on all PowerPc systems ...

powerpc/kernel/iommu: Add new iommu_table_in_use() helper

2021-08-26T14:56:54Z

Having a function to check if the iommu table has any allocation helps deciding if a tbl can be reset for using a new DMA window. It should be enough to replace all instances of !bitmap_empty(tbl...). iommu_table_in_use() skips reserved memory, so we don't need to worry about releasing it before testing. This causes iommu_table_release_pages() to become unnecessary, given it is only used to remove reserved memory for testing. Also, only allow storing reserved memory values in tbl if they are valid in the table, so there is no need to check it in the new helper. Signed-off-by: Leonardo Bras Reviewed-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210817063929.38701-3-leobras.c@gmail.com

powerpc/iommu: don't set failed sg dma_address to DMA_MAPPING_ERROR

2021-08-09T15:13:05Z

Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the ->map_sg calling convention, so remove it. Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/ Suggested-by: Christoph Hellwig Signed-off-by: Logan Gunthorpe Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Geoff Levand Signed-off-by: Christoph Hellwig