kernel.git/drivers/vfio/pci, branch linux-5.4.y

vfio/pci: Enable iowrite64 and ioread64 for vfio pci

2025-03-13T11:43:13Z

[ Upstream commit 2b938e3db335e3670475e31a722c2bee34748c5a ] Definitions of ioread64 and iowrite64 macros in asm/io.h called by vfio pci implementations are enclosed inside check for CONFIG_GENERIC_IOMAP. They don't get defined if CONFIG_GENERIC_IOMAP is defined. Include linux/io-64-nonatomic-lo-hi.h to define iowrite64 and ioread64 macros when they are not defined. io-64-nonatomic-lo-hi.h maps the macros to generic implementation in lib/iomap.c. The generic implementation does 64 bit rw if readq/writeq is defined for the architecture, otherwise it would do 32 bit back to back rw. Note that there are two versions of the generic implementation that differs in the order the 32 bit words are written if 64 bit support is not present. This is not the little/big endian ordering, which is handled separately. This patch uses the lo followed by hi word ordering which is consistent with current back to back implementation in the vfio/pci code. Signed-off-by: Ramesh Thomas Reviewed-by: Jason Gunthorpe Link: https://lore.kernel.org/r/20241210131938.303500-2-ramesh.thomas@intel.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Properly hide first-in-list PCIe extended capability

2024-12-14T18:44:33Z

[ Upstream commit fe4bf8d0b6716a423b16495d55b35d3fe515905d ] There are cases where a PCIe extended capability should be hidden from the user. For example, an unknown capability (i.e., capability with ID greater than PCI_EXT_CAP_ID_MAX) or a capability that is intentionally chosen to be hidden from the user. Hiding a capability is done by virtualizing and modifying the 'Next Capability Offset' field of the previous capability so it points to the capability after the one that should be hidden. The special case where the first capability in the list should be hidden is handled differently because there is no previous capability that can be modified. In this case, the capability ID and version are zeroed while leaving the next pointer intact. This hides the capability and leaves an anchor for the rest of the capability list. However, today, hiding the first capability in the list is not done properly if the capability is unknown, as struct vfio_pci_core_device->pci_config_map is set to the capability ID during initialization but the capability ID is not properly checked later when used in vfio_config_do_rw(). This leads to the following warning [1] and to an out-of-bounds access to ecap_perms array. Fix it by checking cap_id in vfio_config_do_rw(), and if it is greater than PCI_EXT_CAP_ID_MAX, use an alternative struct perm_bits for direct read only access instead of the ecap_perms array. Note that this is safe since the above is the only case where cap_id can exceed PCI_EXT_CAP_ID_MAX (except for the special capabilities, which are already checked before). [1] WARNING: CPU: 118 PID: 5329 at drivers/vfio/pci/vfio_pci_config.c:1900 vfio_pci_config_rw+0x395/0x430 [vfio_pci_core] CPU: 118 UID: 0 PID: 5329 Comm: simx-qemu-syste Not tainted 6.12.0+ #1 (snip) Call Trace: ? show_regs+0x69/0x80 ? __warn+0x8d/0x140 ? vfio_pci_config_rw+0x395/0x430 [vfio_pci_core] ? report_bug+0x18f/0x1a0 ? handle_bug+0x63/0xa0 ? exc_invalid_op+0x19/0x70 ? asm_exc_invalid_op+0x1b/0x20 ? vfio_pci_config_rw+0x395/0x430 [vfio_pci_core] ? vfio_pci_config_rw+0x244/0x430 [vfio_pci_core] vfio_pci_rw+0x101/0x1b0 [vfio_pci_core] vfio_pci_core_read+0x1d/0x30 [vfio_pci_core] vfio_device_fops_read+0x27/0x40 [vfio] vfs_read+0xbd/0x340 ? vfio_device_fops_unl_ioctl+0xbb/0x740 [vfio] ? __rseq_handle_notify_resume+0xa4/0x4b0 __x64_sys_pread64+0x96/0xc0 x64_sys_call+0x1c3d/0x20d0 do_syscall_64+0x4d/0x120 entry_SYSCALL_64_after_hwframe+0x76/0x7e Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Avihai Horon Reviewed-by: Yi Liu Tested-by: Yi Liu Link: https://lore.kernel.org/r/20241124142739.21698-1-avihaih@nvidia.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Create persistent INTx handler

2024-04-13T10:51:34Z

[ Upstream commit 18c198c96a815c962adc2b9b77909eec0be7df4d ] A vulnerability exists where the eventfd for INTx signaling can be deconfigured, which unregisters the IRQ handler but still allows eventfds to be signaled with a NULL context through the SET_IRQS ioctl or through unmask irqfd if the device interrupt is pending. Ideally this could be solved with some additional locking; the igate mutex serializes the ioctl and config space accesses, and the interrupt handler is unregistered relative to the trigger, but the irqfd path runs asynchronous to those. The igate mutex cannot be acquired from the atomic context of the eventfd wake function. Disabling the irqfd relative to the eventfd registration is potentially incompatible with existing userspace. As a result, the solution implemented here moves configuration of the INTx interrupt handler to track the lifetime of the INTx context object and irq_type configuration, rather than registration of a particular trigger eventfd. Synchronization is added between the ioctl path and eventfd_signal() wrapper such that the eventfd trigger can be dynamically updated relative to in-flight interrupts or irqfd callbacks. Cc: Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Reported-by: Reinette Chatre Reviewed-by: Kevin Tian Reviewed-by: Reinette Chatre Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240308230557.805580-5-alex.williamson@redhat.com Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio/pci: Lock external INTx masking ops

2024-04-13T10:51:34Z

[ Upstream commit 810cd4bb53456d0503cc4e7934e063835152c1b7 ] Mask operations through config space changes to DisINTx may race INTx configuration changes via ioctl. Create wrappers that add locking for paths outside of the core interrupt code. In particular, irq_type is updated holding igate, therefore testing is_intx() requires holding igate. For example clearing DisINTx from config space can otherwise race changes of the interrupt configuration. This aligns interfaces which may trigger the INTx eventfd into two camps, one side serialized by igate and the other only enabled while INTx is configured. A subsequent patch introduces synchronization for the latter flows. Cc: Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Reported-by: Reinette Chatre Reviewed-by: Kevin Tian Reviewed-by: Reinette Chatre Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240308230557.805580-3-alex.williamson@redhat.com Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio/pci: Disable auto-enable of exclusive INTx IRQ

2024-04-13T10:51:34Z

[ Upstream commit fe9a7082684eb059b925c535682e68c34d487d43 ] Currently for devices requiring masking at the irqchip for INTx, ie. devices without DisINTx support, the IRQ is enabled in request_irq() and subsequently disabled as necessary to align with the masked status flag. This presents a window where the interrupt could fire between these events, resulting in the IRQ incrementing the disable depth twice. This would be unrecoverable for a user since the masked flag prevents nested enables through vfio. Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx is never auto-enabled, then unmask as required. Cc: Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Reviewed-by: Kevin Tian Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20240308230557.805580-2-alex.williamson@redhat.com Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio/pci: Handle concurrent vma faults

2021-07-14T14:53:47Z

[ Upstream commit 6a45ece4c9af473555f01f0f8b97eba56e3c7d0d ] io_remap_pfn_range() will trigger a BUG_ON if it encounters a populated pte within the mapping range. This can occur because we map the entire vma on fault and multiple faults can be blocked behind the vma_lock. This leads to traces like the one reported below. We can use our vma_list to test whether a given vma is mapped to avoid this issue. [ 1591.733256] kernel BUG at mm/memory.c:2177! [ 1591.739515] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 1591.747381] Modules linked in: vfio_iommu_type1 vfio_pci vfio_virqfd vfio pv680_mii(O) [ 1591.760536] CPU: 2 PID: 227 Comm: lcore-worker-2 Tainted: G O 5.11.0-rc3+ #1 [ 1591.770735] Hardware name: , BIOS HixxxxFPGA 1P B600 V121-1 [ 1591.778872] pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--) [ 1591.786134] pc : remap_pfn_range+0x214/0x340 [ 1591.793564] lr : remap_pfn_range+0x1b8/0x340 [ 1591.799117] sp : ffff80001068bbd0 [ 1591.803476] x29: ffff80001068bbd0 x28: 0000042eff6f0000 [ 1591.810404] x27: 0000001100910000 x26: 0000001300910000 [ 1591.817457] x25: 0068000000000fd3 x24: ffffa92f1338e358 [ 1591.825144] x23: 0000001140000000 x22: 0000000000000041 [ 1591.832506] x21: 0000001300910000 x20: ffffa92f141a4000 [ 1591.839520] x19: 0000001100a00000 x18: 0000000000000000 [ 1591.846108] x17: 0000000000000000 x16: ffffa92f11844540 [ 1591.853570] x15: 0000000000000000 x14: 0000000000000000 [ 1591.860768] x13: fffffc0000000000 x12: 0000000000000880 [ 1591.868053] x11: ffff0821bf3d01d0 x10: ffff5ef2abd89000 [ 1591.875932] x9 : ffffa92f12ab0064 x8 : ffffa92f136471c0 [ 1591.883208] x7 : 0000001140910000 x6 : 0000000200000000 [ 1591.890177] x5 : 0000000000000001 x4 : 0000000000000001 [ 1591.896656] x3 : 0000000000000000 x2 : 0168044000000fd3 [ 1591.903215] x1 : ffff082126261880 x0 : fffffc2084989868 [ 1591.910234] Call trace: [ 1591.914837] remap_pfn_range+0x214/0x340 [ 1591.921765] vfio_pci_mmap_fault+0xac/0x130 [vfio_pci] [ 1591.931200] __do_fault+0x44/0x12c [ 1591.937031] handle_mm_fault+0xcc8/0x1230 [ 1591.942475] do_page_fault+0x16c/0x484 [ 1591.948635] do_translation_fault+0xbc/0xd8 [ 1591.954171] do_mem_abort+0x4c/0xc0 [ 1591.960316] el0_da+0x40/0x80 [ 1591.965585] el0_sync_handler+0x168/0x1b0 [ 1591.971608] el0_sync+0x174/0x180 [ 1591.978312] Code: eb1b027f 540000c0 f9400022 b4fffe02 (d4210000) Fixes: 11c4cd07ba11 ("vfio-pci: Fault mmaps to enable vma tracking") Reported-by: Zeng Tao Suggested-by: Zeng Tao Link: https://lore.kernel.org/r/162497742783.3883260.3282953006487785034.stgit@omen Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: zap_vma_ptes() needs MMU

2021-06-10T11:37:03Z

[ Upstream commit 2a55ca37350171d9b43d561528f23d4130097255 ] zap_vma_ptes() is only available when CONFIG_MMU is set/enabled. Without CONFIG_MMU, vfio_pci.o has build errors, so make VFIO_PCI depend on MMU. riscv64-linux-ld: drivers/vfio/pci/vfio_pci.o: in function `vfio_pci_mmap_open': vfio_pci.c:(.text+0x1ec): undefined reference to `zap_vma_ptes' riscv64-linux-ld: drivers/vfio/pci/vfio_pci.o: in function `.L0 ': vfio_pci.c:(.text+0x165c): undefined reference to `zap_vma_ptes' Fixes: 11c4cd07ba11 ("vfio-pci: Fault mmaps to enable vma tracking") Signed-off-by: Randy Dunlap Reported-by: kernel test robot Cc: Alex Williamson Cc: Cornelia Huck Cc: kvm@vger.kernel.org Cc: Jason Gunthorpe Cc: Eric Auger Message-Id: <20210515190856.2130-1-rdunlap@infradead.org> Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Fix error return code in vfio_ecap_init()

2021-06-10T11:37:03Z

[ Upstream commit d1ce2c79156d3baf0830990ab06d296477b93c26 ] The error code returned from vfio_ext_cap_len() is stored in 'len', not in 'ret'. Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Reported-by: Hulk Robot Signed-off-by: Zhen Lei Reviewed-by: Max Gurtovoy Message-Id: <20210515020458.6771-1-thunder.leizhen@huawei.com> Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

vfio/pci: Add missing range check in vfio_pci_mmap

2021-04-21T10:56:16Z

commit 909290786ea335366e21d7f1ed5812b90f2f0a92 upstream. When mmaping an extra device region verify that the region index derived from the mmap offset is valid. Fixes: a15b1883fee1 ("vfio_pci: Allow mapping extra regions") Cc: stable@vger.kernel.org Signed-off-by: Christian A. Ehrhardt Message-Id: <20210412214124.GA241759@lisa.in-ulm.de> Reviewed-by: David Gibson Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

vfio/nvlink: Add missing SPAPR_TCE_IOMMU depends

2021-04-07T12:47:43Z

commit e0146a108ce4d2c22b9510fd12268e3ee72a0161 upstream. Compiling the nvlink stuff relies on the SPAPR_TCE_IOMMU otherwise there are compile errors: drivers/vfio/pci/vfio_pci_nvlink2.c:101:10: error: implicit declaration of function 'mm_iommu_put' [-Werror,-Wimplicit-function-declaration] ret = mm_iommu_put(data->mm, data->mem); As PPC only defines these functions when the config is set. Previously this wasn't a problem by chance as SPAPR_TCE_IOMMU was the only IOMMU that could have satisfied IOMMU_API on POWERNV. Fixes: 179209fa1270 ("vfio: IOMMU_API should be selected") Reported-by: kernel test robot Signed-off-by: Jason Gunthorpe Message-Id: <0-v1-83dba9768fc3+419-vfio_nvlink2_kconfig_jgg@nvidia.com> Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman