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path: root/drivers/vfio/pci/vfio_pci_config.c
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2025-04-14vfio/pci: Virtualize zero INTx PIN if no pdev->irqAlex Williamson
Typically pdev->irq is consistent with whether the device itself supports INTx, where device support is reported via the PIN register. Therefore the PIN register is often already zero if pdev->irq is zero. Recently virtualization of the PIN register was expanded to include the case where the device supports INTx but the platform does not route the interrupt. This is reported by a value of IRQ_NOTCONNECTED on some architectures. Other architectures just report zero for pdev->irq. We already disallow INTx setup if pdev->irq is zero, therefore add this to the PIN register virtualization criteria so that a consistent view is provided to userspace through virtualized config space and ioctls. Reported-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> Link: https://lore.kernel.org/all/174231895238.2295.12586708771396482526.stgit@linux.ibm.com/ Tested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com> Link: https://lore.kernel.org/r/20250320194145.2816379-1-alex.williamson@redhat.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-03-17vfio/pci: Handle INTx IRQ_NOTCONNECTEDAlex Williamson
Some systems report INTx as not routed by setting pdev->irq to IRQ_NOTCONNECTED, resulting in a -ENOTCONN error when trying to setup eventfd signaling. Include this in the set of conditions for which the PIN register is virtualized to zero. Additionally consolidate vfio_pci_get_irq_count() to use this virtualized value in reporting INTx support via ioctl and sanity checking ioctl paths since pdev->irq is re-used when the device is in MSI mode. The combination of these results in both the config space of the device and the ioctl interface behaving as if the device does not support INTx. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Link: https://lore.kernel.org/r/20250311230623.1264283-1-alex.williamson@redhat.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-01-28Merge tag 'vfio-v6.14-rc1' of https://github.com/awilliam/linux-vfioLinus Torvalds
Pull vfio updates from Alex Williamson: - Extend vfio-pci 8-byte read/write support to include archs defining CONFIG_GENERIC_IOMAP, such as x86, and remove now extraneous #ifdefs around 64-bit accessors (Ramesh Thomas) - Update vfio-pci shadow ROM handling and allow cached ROM from setup data to be exposed as a functional ROM BAR region when available (Yunxiang Li) - Update nvgrace-gpu vfio-pci variant driver for new Grace Blackwell hardware, conditionalizing the uncached BAR workaround for previous generation hardware based on the presence of a flag in a new DVSEC capability, and include a delay during probe for link training to complete, a new requirement for GB devices (Ankit Agrawal) * tag 'vfio-v6.14-rc1' of https://github.com/awilliam/linux-vfio: vfio/nvgrace-gpu: Add GB200 SKU to the devid table vfio/nvgrace-gpu: Check the HBM training and C2C link status vfio/nvgrace-gpu: Expose the blackwell device PF BAR1 to the VM vfio/nvgrace-gpu: Read dvsec register to determine need for uncached resmem vfio/platform: check the bounds of read/write syscalls vfio/pci: Expose setup ROM at ROM bar when needed vfio/pci: Remove shadow ROM specific code paths vfio/pci: Remove #ifdef iowrite64 and #ifdef ioread64 vfio/pci: Enable iowrite64 and ioread64 for vfio pci
2025-01-21PCI: Remove redundant PCI_VSEC_HDR and PCI_VSEC_HDR_LEN_SHIFTDongdong Zhang
Remove duplicate macro PCI_VSEC_HDR and its related macro PCI_VSEC_HDR_LEN_SHIFT from pci_regs.h to avoid redundancy and inconsistencies. Update VFIO PCI code to use PCI_VNDR_HEADER and PCI_VNDR_HEADER_LEN() for consistent naming and functionality. These changes aim to streamline header handling while minimizing impact, given the niche usage of these macros in userspace. Link: https://lore.kernel.org/r/20241216013536.4487-1-zhangdongdong@eswincomputing.com Signed-off-by: Dongdong Zhang <zhangdongdong@eswincomputing.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Williamson <alex.williamson@redhat.com>
2025-01-06vfio/pci: Expose setup ROM at ROM bar when neededYunxiang Li
If ROM bar is missing for any reason, we can fallback to using pdev->rom to expose the ROM content to the guest. This fixes some passthrough use cases where the upstream bridge does not have enough address window. Signed-off-by: Yunxiang Li <Yunxiang.Li@amd.com> Link: https://lore.kernel.org/r/20250102185013.15082-3-Yunxiang.Li@amd.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2025-01-06vfio/pci: Remove shadow ROM specific code pathsYunxiang Li
After commit 0c0e0736acad ("PCI: Set ROM shadow location in arch code, not in PCI core"), the shadow ROM works the same as regular ROM BARs so these code paths are no longer needed. Signed-off-by: Yunxiang Li <Yunxiang.Li@amd.com> Link: https://lore.kernel.org/r/20250102185013.15082-2-Yunxiang.Li@amd.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2024-11-25vfio/pci: Properly hide first-in-list PCIe extended capabilityAvihai Horon
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: <TASK> ? 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 <avihaih@nvidia.com> Reviewed-by: Yi Liu <yi.l.liu@intel.com> Tested-by: Yi Liu <yi.l.liu@intel.com> Link: https://lore.kernel.org/r/20241124142739.21698-1-avihaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2024-02-22vfio/pci: rename and export range_intersect_rangeAnkit Agrawal
range_intersect_range determines an overlap between two ranges. If an overlap, the helper function returns the overlapping offset and size. The VFIO PCI variant driver emulates the PCI config space BAR offset registers. These offset may be accessed for read/write with a variety of lengths including sub-word sizes from sub-word offsets. The driver makes use of this helper function to read/write the targeted part of the emulated register. Make this a vfio_pci_core function, rename and export as GPL. Also update references in virtio driver. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reviewed-by: Yishai Hadas <yishaih@nvidia.com> Signed-off-by: Ankit Agrawal <ankita@nvidia.com> Link: https://lore.kernel.org/r/20240220115055.23546-3-ankita@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-05-26vfio/pci: Also demote hiding standard cap messagesAlex Williamson
Apply the same logic as commit 912b625b4dcf ("vfio/pci: demote hiding ecap messages to debug level") for the less common case of hiding standard capabilities. Reviewed-by: Oleksandr Natalenko <oleksandr@natalenko.name> Reviewed-by: Cédric Le Goater <clg@redhat.com> Link: https://lore.kernel.org/r/20230523225250.1215911-1-alex.williamson@redhat.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-05-23vfio/pci: demote hiding ecap messages to debug levelOleksandr Natalenko
Seeing a burst of messages like this: vfio-pci 0000:98:00.0: vfio_ecap_init: hiding ecap 0x19@0x1d0 vfio-pci 0000:98:00.0: vfio_ecap_init: hiding ecap 0x25@0x200 vfio-pci 0000:98:00.0: vfio_ecap_init: hiding ecap 0x26@0x210 vfio-pci 0000:98:00.0: vfio_ecap_init: hiding ecap 0x27@0x250 vfio-pci 0000:98:00.1: vfio_ecap_init: hiding ecap 0x25@0x200 vfio-pci 0000:b1:00.0: vfio_ecap_init: hiding ecap 0x19@0x1d0 vfio-pci 0000:b1:00.0: vfio_ecap_init: hiding ecap 0x25@0x200 vfio-pci 0000:b1:00.0: vfio_ecap_init: hiding ecap 0x26@0x210 vfio-pci 0000:b1:00.0: vfio_ecap_init: hiding ecap 0x27@0x250 vfio-pci 0000:b1:00.1: vfio_ecap_init: hiding ecap 0x25@0x200 is of little to no value for an ordinary user. Hence, use pci_dbg() instead of pci_info(). Signed-off-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Cédric Le Goater <clg@redhat.com> Tested-by: YangHang Liu <yanghliu@redhat.com> Link: https://lore.kernel.org/r/20230504131654.24922-1-oleksandr@natalenko.name Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-04-14vfio/pci: Add DVSEC PCI Extended Config Capability to user visible list.K V P, Satyanarayana
The Designated Vendor-Specific Extended Capability (DVSEC Capability) is an optional Extended Capability that is permitted to be implemented by any PCI Express Function. This allows PCI Express component vendors to use the Extended Capability mechanism to expose vendor-specific registers that can be present in components by a variety of vendors. A DVSEC Capability structure can tell vendor-specific software which features a particular component supports. An example usage of DVSEC is Intel Platform Monitoring Technology (PMT) for enumerating and accessing hardware monitoring capabilities on a device. PMT encompasses three device monitoring features, Telemetry (device metrics), Watcher (sampling/tracing), and Crashlog. The DVSEC is used to discover these features and provide a BAR offset to their registers with the Intel vendor code. The current VFIO driver does not pass DVSEC capabilities to Virtual Machine (VM) which makes PMT not to work inside the virtual machine. This series adds DVSEC capability to user visible list to allow its use with VFIO. VFIO supports passing of Vendor Specific Extended Capability (VSEC) and raw write access to device. DVSEC also passed to VM in the same way as of VSEC. Signed-off-by: K V P Satyanarayana <satyanarayana.k.v.p@intel.com> Link: https://lore.kernel.org/r/20230317082222.3355912-1-satyanarayana.k.v.p@intel.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2023-01-23vfio: Use GFP_KERNEL_ACCOUNT for userspace persistent allocationsJason Gunthorpe
Use GFP_KERNEL_ACCOUNT for userspace persistent allocations. The GFP_KERNEL_ACCOUNT option lets the memory allocator know that this is untrusted allocation triggered from userspace and should be a subject of kmem accounting, and as such it is controlled by the cgroup mechanism. The way to find the relevant allocations was for example to look at the close_device function and trace back all the kfrees to their allocations. Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20230108154427.32609-4-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio/pci: Simplify the is_intx/msi/msix/etc definesJason Gunthorpe
Only three of these are actually used, simplify to three inline functions, and open code the if statement in vfio_pci_config.c. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/3-v2-1bd95d72f298+e0e-vfio_pci_priv_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-09-01vfio/pci: Split linux/vfio_pci_core.hJason Gunthorpe
The header in include/linux should have only the exported interface for other vfio_pci modules to use. Internal definitions for vfio_pci.ko should be in a "priv" header along side the .c files. Move the internal declarations out of vfio_pci_core.h. They either move to vfio_pci_priv.h or to the C file that is the only user. Reviewed-by: Kevin Tian <kevin.tian@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Link: https://lore.kernel.org/r/1-v2-1bd95d72f298+e0e-vfio_pci_priv_jgg@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-08-01vfio/pci: fix the wrong wordBo Liu
This patch fixes a wrong word in comment. Signed-off-by: Bo Liu <liubo03@inspur.com> Link: https://lore.kernel.org/r/20220801013918.2520-1-liubo03@inspur.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-07-06vfio/pci: fix the wrong wordBo Liu
This patch fixes a wrong word in comment. Signed-off-by: Bo Liu <liubo03@inspur.com> Link: https://lore.kernel.org/r/20220704023649.3913-1-liubo03@inspur.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-18vfio/pci: Virtualize PME related registers bits and initialize to zeroAbhishek Sahu
If any PME event will be generated by PCI, then it will be mostly handled in the host by the root port PME code. For example, in the case of PCIe, the PME event will be sent to the root port and then the PME interrupt will be generated. This will be handled in drivers/pci/pcie/pme.c at the host side. Inside this, the pci_check_pme_status() will be called where PME_Status and PME_En bits will be cleared. So, the guest OS which is using vfio-pci device will not come to know about this PME event. To handle these PME events inside guests, we need some framework so that if any PME events will happen, then it needs to be forwarded to virtual machine monitor. We can virtualize PME related registers bits and initialize these bits to zero so vfio-pci device user will assume that it is not capable of asserting the PME# signal from any power state. Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com> Link: https://lore.kernel.org/r/20220518111612.16985-4-abhsahu@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-05-18vfio/pci: Invalidate mmaps and block the access in D3hot power stateAbhishek Sahu
According to [PCIe v5 5.3.1.4.1] for D3hot state "Configuration and Message requests are the only TLPs accepted by a Function in the D3Hot state. All other received Requests must be handled as Unsupported Requests, and all received Completions may optionally be handled as Unexpected Completions." Currently, if the vfio PCI device has been put into D3hot state and if user makes non-config related read/write request in D3hot state, these requests will be forwarded to the host and this access may cause issues on a few systems. This patch leverages the memory-disable support added in commit 'abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory")' to generate page fault on mmap access and return error for the direct read/write. If the device is D3hot state, then the error will be returned for MMIO access. The IO access generally does not make the system unresponsive so the IO access can still happen in D3hot state. The default value should be returned in this case without bringing down the complete system. Also, the power related structure fields need to be protected so we can use the same 'memory_lock' to protect these fields also. This protection is mainly needed when user changes the PCI power state by writing into PCI_PM_CTRL register. vfio_lock_and_set_power_state() wrapper function will take the required locks and then it will invoke the vfio_pci_set_power_state(). Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com> Link: https://lore.kernel.org/r/20220518111612.16985-2-abhsahu@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-26vfio/pci: Introduce vfio_pci_core.koMax Gurtovoy
Now that vfio_pci has been split into two source modules, one focusing on the "struct pci_driver" (vfio_pci.c) and a toolbox library of code (vfio_pci_core.c), complete the split and move them into two different kernel modules. As before vfio_pci.ko continues to present the same interface under sysfs and this change will have no functional impact. Splitting into another module and adding exports allows creating new HW specific VFIO PCI drivers that can implement device specific functionality, such as VFIO migration interfaces or specialized device requirements. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20210826103912.128972-14-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-26vfio/pci: Rename vfio_pci_device to vfio_pci_core_deviceMax Gurtovoy
This is a preparation patch for separating the vfio_pci driver to a subsystem driver and a generic pci driver. This patch doesn't change any logic. The new vfio_pci_core_device structure will be the main structure of the core driver and later on vfio_pci_device structure will be the main structure of the generic vfio_pci driver. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20210826103912.128972-4-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-08-26vfio/pci: Rename vfio_pci_private.h to vfio_pci_core.hMax Gurtovoy
This is a preparation patch for separating the vfio_pci driver to a subsystem driver and a generic pci driver. This patch doesn't change any logic. Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Yishai Hadas <yishaih@nvidia.com> Link: https://lore.kernel.org/r/20210826103912.128972-3-yishaih@nvidia.com Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-05-24vfio/pci: Fix error return code in vfio_ecap_init()Zhen Lei
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 <hulkci@huawei.com> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Message-Id: <20210515020458.6771-1-thunder.leizhen@huawei.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2021-04-06vfio/pci: fix a couple of spelling mistakesZhen Lei
There are several spelling mistakes, as follows: thru ==> through presense ==> presence Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Message-Id: <20210326083528.1329-4-thunder.leizhen@huawei.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-09-22Merge branches 'v5.10/vfio/bardirty', 'v5.10/vfio/dma_avail', ↵Alex Williamson
'v5.10/vfio/misc', 'v5.10/vfio/no-cmd-mem' and 'v5.10/vfio/yan_zhao_fixes' into v5.10/vfio/next
2020-09-22vfio/pci: Decouple PCI_COMMAND_MEMORY bit checks from is_virtfnMatthew Rosato
While it is true that devices with is_virtfn=1 will have a Memory Space Enable bit that is hard-wired to 0, this is not the only case where we see this behavior -- For example some bare-metal hypervisors lack Memory Space Enable bit emulation for devices not setting is_virtfn (s390). Fix this by instead checking for the newly-added no_command_memory bit which directly denotes the need for PCI_COMMAND_MEMORY emulation in vfio. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-09-21vfio/pci: Don't regenerate vconfig for all BARs if !bardirtyZenghui Yu
Now we regenerate vconfig for all the BARs via vfio_bar_fixup(), every time any offset of any of them are read. Though BARs aren't re-read regularly, the regeneration can be avoided if no BARs had been written since they were last read, in which case vdev->bardirty is false. Let's return immediately in vfio_bar_fixup() if bardirty is false. Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-06-25vfio/pci: Fix SR-IOV VF handling with MMIO blockingAlex Williamson
SR-IOV VFs do not implement the memory enable bit of the command register, therefore this bit is not set in config space after pci_enable_device(). This leads to an unintended difference between PF and VF in hand-off state to the user. We can correct this by setting the initial value of the memory enable bit in our virtualized config space. There's really no need however to ever fault a user on a VF though as this would only indicate an error in the user's management of the enable bit, versus a PF where the same access could trigger hardware faults. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-05-26Merge branches 'v5.8/vfio/alex-block-mmio-v3', 'v5.8/vfio/alex-zero-cap-v2' ↵Alex Williamson
and 'v5.8/vfio/qian-leak-fixes' into v5.8/vfio/next
2020-05-18vfio/pci: fix memory leaks in alloc_perm_bits()Qian Cai
vfio_pci_disable() calls vfio_config_free() but forgets to call free_perm_bits() resulting in memory leaks, unreferenced object 0xc000000c4db2dee0 (size 16): comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s) hex dump (first 16 bytes): 00 00 ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................ backtrace: [<00000000a6a4552d>] alloc_perm_bits+0x58/0xe0 [vfio_pci] [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci] init_pci_cap_msi_perm at drivers/vfio/pci/vfio_pci_config.c:1125 (inlined by) vfio_msi_cap_len at drivers/vfio/pci/vfio_pci_config.c:1180 (inlined by) vfio_cap_len at drivers/vfio/pci/vfio_pci_config.c:1241 (inlined by) vfio_cap_init at drivers/vfio/pci/vfio_pci_config.c:1468 (inlined by) vfio_config_init at drivers/vfio/pci/vfio_pci_config.c:1707 [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci] [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio] [<000000009e34c54f>] ksys_ioctl+0xd8/0x130 [<000000006577923d>] sys_ioctl+0x28/0x40 [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0 [<0000000008ea7dd5>] system_call_common+0xf0/0x278 unreferenced object 0xc000000c4db2e330 (size 16): comm "qemu-kvm", pid 4305, jiffies 4295020272 (age 3463.780s) hex dump (first 16 bytes): 00 ff ff 00 ff ff ff ff ff ff ff ff ff ff 00 00 ................ backtrace: [<000000004c71914f>] alloc_perm_bits+0x44/0xe0 [vfio_pci] [<00000000ac990549>] vfio_config_init+0xdf0/0x11b0 [vfio_pci] [<000000006db873a1>] vfio_pci_open+0x234/0x700 [vfio_pci] [<00000000630e1906>] vfio_group_fops_unl_ioctl+0x8e0/0xb84 [vfio] [<000000009e34c54f>] ksys_ioctl+0xd8/0x130 [<000000006577923d>] sys_ioctl+0x28/0x40 [<000000006d7b1cf2>] system_call_exception+0x114/0x1e0 [<0000000008ea7dd5>] system_call_common+0xf0/0x278 Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver") Signed-off-by: Qian Cai <cai@lca.pw> [aw: rolled in follow-up patch] Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-05-18vfio-pci: Mask cap zeroAlex Williamson
The PCI Code and ID Assignment Specification changed capability ID 0 from reserved to a NULL capability in the v1.1 revision. The NULL capability is defined to include only the 16-bit capability header, ie. only the ID and next pointer. Unfortunately vfio-pci creates a map of config space, where ID 0 is used to reserve the standard type 0 header. Finding an actual capability with this ID therefore results in a bogus range marked in that map and conflicts with subsequent capabilities. As this seems to be a dummy capability anyway and we already support dropping capabilities, let's hide this one rather than delving into the potentially subtle dependencies within our map. Seen on an NVIDIA Tesla T4. Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2020-05-18vfio-pci: Invalidate mmaps and block MMIO access on disabled memoryAlex Williamson
Accessing the disabled memory space of a PCI device would typically result in a master abort response on conventional PCI, or an unsupported request on PCI express. The user would generally see these as a -1 response for the read return data and the write would be silently discarded, possibly with an uncorrected, non-fatal AER error triggered on the host. Some systems however take it upon themselves to bring down the entire system when they see something that might indicate a loss of data, such as this discarded write to a disabled memory space. To avoid this, we want to try to block the user from accessing memory spaces while they're disabled. We start with a semaphore around the memory enable bit, where writers modify the memory enable state and must be serialized, while readers make use of the memory region and can access in parallel. Writers include both direct manipulation via the command register, as well as any reset path where the internal mechanics of the reset may both explicitly and implicitly disable memory access, and manipulation of the MSI-X configuration, where the MSI-X vector table resides in MMIO space of the device. Readers include the read and write file ops to access the vfio device fd offsets as well as memory mapped access. In the latter case, we make use of our new vma list support to zap, or invalidate, those memory mappings in order to force them to be faulted back in on access. Our semaphore usage will stall user access to MMIO spaces across internal operations like reset, but the user might experience new behavior when trying to access the MMIO space while disabled via the PCI command register. Access via read or write while disabled will return -EIO and access via memory maps will result in a SIGBUS. This is expected to be compatible with known use cases and potentially provides better error handling capabilities than present in the hardware, while avoiding the more readily accessible and severe platform error responses that might otherwise occur. Fixes: CVE-2020-12888 Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-10-14PCI: Add PCI_STD_NUM_BARS for the number of standard BARsDenis Efremov
Code that iterates over all standard PCI BARs typically uses PCI_STD_RESOURCE_END. However, that requires the unusual test "i <= PCI_STD_RESOURCE_END" rather than something the typical "i < PCI_STD_NUM_BARS". Add a definition for PCI_STD_NUM_BARS and change loops to use the more idiomatic C style to help avoid fencepost errors. Link: https://lore.kernel.org/r/20190927234026.23342-1-efremov@linux.com Link: https://lore.kernel.org/r/20190927234308.23935-1-efremov@linux.com Link: https://lore.kernel.org/r/20190916204158.6889-3-efremov@linux.com Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Sebastian Ott <sebott@linux.ibm.com> # arch/s390/ Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> # video/fbdev/ Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com> # pci/controller/dwc/ Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com> # scsi/pm8001/ Acked-by: Martin K. Petersen <martin.petersen@oracle.com> # scsi/pm8001/ Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # memstick/
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner
Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-22vfio: Use dev_printk() when possibleBjorn Helgaas
Use dev_printk() when possible to make messages consistent with other device-related messages. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2019-02-18vfio/pci: Restore device state on PM transitionAlex Williamson
PCI core handles save and restore of device state around reset, but when using pci_set_power_state() we can unintentionally trigger a soft reset of the device, where PCI core only restores the BAR state. If we're using vfio-pci's idle D3 support to try to put devices into low power when unused, this might trigger a reset when the device is woken for use. Also power state management by the user, or within a guest, can put the device into D3 power state with potentially limited ability to restore the device if it should undergo a reset. The PCI spec does not define the extent of a soft reset and many devices reporting soft reset on D3->D0 transition do not undergo a PCI config space reset. It's therefore assumed safe to unconditionally restore the remainder of the state if the device indicates soft reset support, even on a user initiated wakeup. Implement a wrapper in vfio-pci to tag devices reporting PM reset support, save their state on transitions into D3 and restore on transitions back to D0. Reported-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-09-25vfio/pci: Mask buggy SR-IOV VF INTx supportAlex Williamson
The SR-IOV spec requires that VFs must report zero for the INTx pin register as VFs are precluded from INTx support. It's much easier for the host kernel to understand whether a device is a VF and therefore whether a non-zero pin register value is bogus than it is to do the same in userspace. Override the INTx count for such devices and virtualize the pin register to provide a consistent view of the device to the user. As this is clearly a spec violation, warn about it to support hardware validation, but also provide a known whitelist as it doesn't do much good to continue complaining if the hardware vendor doesn't plan to fix it. Known devices with this issue: 8086:270c Tested-by: Gage Eads <gage.eads@intel.com> Reviewed-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2018-09-25vfio/pci: Fix potential memory leak in vfio_msi_cap_lenLi Qiang
Free allocated vdev->msi_perm in error path. Signed-off-by: Li Qiang <liq3ea@gmail.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-10-02vfio/pci: Virtualize Maximum Read Request SizeAlex Williamson
MRRS defines the maximum read request size a device is allowed to make. Drivers will often increase this to allow more data transfer with a single request. Completions to this request are bound by the MPS setting for the bus. Aside from device quirks (none known), it doesn't seem to make sense to set an MRRS value less than MPS, yet this is a likely scenario given that user drivers do not have a system-wide view of the PCI topology. Virtualize MRRS such that the user can set MRRS >= MPS, but use MPS as the floor value that we'll write to hardware. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2017-10-02vfio/pci: Virtualize Maximum Payload SizeAlex Williamson
With virtual PCI-Express chipsets, we now see userspace/guest drivers trying to match the physical MPS setting to a virtual downstream port. Of course a lone physical device surrounded by virtual interconnects cannot make a correct decision for a proper MPS setting. Instead, let's virtualize the MPS control register so that writes through to hardware are disallowed. Userspace drivers like QEMU assume they can write anything to the device and we'll filter out anything dangerous. Since mismatched MPS can lead to AER and other faults, let's add it to the kernel side rather than relying on userspace virtualization to handle it. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Eric Auger <eric.auger@redhat.com>
2017-07-27vfio/pci: Fix handling of RC integrated endpoint PCIe capability sizeAlex Williamson
Root complex integrated endpoints do not have a link and therefore may use a smaller PCIe capability in config space than we expect when building our config map. Add a case for these to avoid reporting an erroneous overlap. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-12-15Merge tag 'pci-v4.10-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI changes: - add support for PCI on ARM64 boxes with ACPI. We already had this for theoretical spec-compliant hardware; now we're adding quirks for the actual hardware (Cavium, HiSilicon, Qualcomm, X-Gene) - add runtime PM support for hotplug ports - enable runtime suspend for Intel UHCI that uses platform-specific wakeup signaling - add yet another host bridge registration interface. We hope this is extensible enough to subsume the others - expose device revision in sysfs for DRM - to avoid device conflicts, make sure any VF BAR updates are done before enabling the VF - avoid unnecessary link retrains for ASPM - allow INTx masking on Mellanox devices that support it - allow access to non-standard VPD for Chelsio devices - update Broadcom iProc support for PAXB v2, PAXC v2, inbound DMA, etc - update Rockchip support for max-link-speed - add NVIDIA Tegra210 support - add Layerscape LS1046a support - update R-Car compatibility strings - add Qualcomm MSM8996 support - remove some uninformative bootup messages" * tag 'pci-v4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (115 commits) PCI: Enable access to non-standard VPD for Chelsio devices (cxgb3) PCI: Expand "VPD access disabled" quirk message PCI: pciehp: Remove loading message PCI: hotplug: Remove hotplug core message PCI: Remove service driver load/unload messages PCI/AER: Log AER IRQ when claiming Root Port PCI/AER: Log errors with PCI device, not PCIe service device PCI/AER: Remove unused version macros PCI/PME: Log PME IRQ when claiming Root Port PCI/PME: Drop unused support for PMEs from Root Complex Event Collectors PCI: Move config space size macros to pci_regs.h x86/platform/intel-mid: Constify mid_pci_platform_pm PCI/ASPM: Don't retrain link if ASPM not possible PCI: iproc: Skip check for legacy IRQ on PAXC buses PCI: pciehp: Leave power indicator on when enabling already-enabled slot PCI: pciehp: Prioritize data-link event over presence detect PCI: rcar: Add gen3 fallback compatibility string for pcie-rcar PCI: rcar: Use gen2 fallback compatibility last PCI: rcar-gen2: Use gen2 fallback compatibility last PCI: rockchip: Move the deassert of pm/aclk/pclk after phy_init() ..
2016-12-12PCI: Move config space size macros to pci_regs.hWang Sheng-Hui
Move PCI configuration space size macros (PCI_CFG_SPACE_SIZE and PCI_CFG_SPACE_EXP_SIZE) from drivers/pci/pci.h to include/uapi/linux/pci_regs.h so they can be used by more drivers and eliminate duplicate definitions. [bhelgaas: Expand comment to include PCI-X details] Signed-off-by: Wang Sheng-Hui <shhuiw@foxmail.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2016-11-18vfio/pci: Drop unnecessary pcibios_err_to_errno()Cao jin
As of commit d97ffe236894 ("PCI: Fix return value from pci_user_{read,write}_config_*()") it's unnecessary to call pcibios_err_to_errno() to fixup the return value from these functions. pcibios_err_to_errno() already does simple passthrough of -errno values, therefore no functional change is expected. [aw: changelog] Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-09-26vfio-pci: Virtualize PCIe & AF FLRAlex Williamson
We use a BAR restore trick to try to detect when a user has performed a device reset, possibly through FLR or other backdoors, to put things back into a working state. This is important for backdoor resets, but we can actually just virtualize the "front door" resets provided via PCIe and AF FLR. Set these bits as virtualized + writable, allowing the default write to set them in vconfig, then we can simply check the bit, perform an FLR of our own, and clear the bit. We don't actually have the granularity in PCI to specify the type of reset we want to do, but generally devices don't implement both PCIe and AF FLR and we'll favor these over other types of reset, so we should generally lineup. We do test whether the device provides the requested FLR type to stay consistent with hardware capabilities though. This seems to fix several instance of devices getting into bad states with userspace drivers, like dpdk, running inside a VM. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Reviewed-by: Greg Rose <grose@lightfleet.com>
2016-08-29vfio/pci: Fix typos in commentsWei Jiangang
Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-31vfio/pci: Allow VPD short readAlex Williamson
The size of the VPD area is not necessarily 4-byte aligned, so a pci_vpd_read() might return less than 4 bytes. Zero our buffer and accept anything other than an error. Intel X710 NICs exercise this. Fixes: 4e1a635552d3 ("vfio/pci: Use kernel VPD access functions") Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-19vfio_pci: Test for extended capabilities if config space > 256 bytesAlexey Kardashevskiy
PCI-Express spec says that reading 4 bytes at offset 100h should return zero if there is no extended capability so VFIO reads this dword to know if there are extended capabilities. However it is not always possible to access the extended space so generic PCI code in pci_cfg_space_size_ext() checks if pci_read_config_dword() can read beyond 100h and if the check fails, it sets the config space size to 100h. VFIO does its own extended capabilities check by reading at offset 100h which may produce 0xffffffff which VFIO treats as the extended config space presense and calls vfio_ecap_init() which fails to parse capabilities (which is expected) but right before the exit, it writes zero at offset 100h which is beyond the buffer allocated for vdev->vconfig (which is 256 bytes) which leads to random memory corruption. This makes VFIO only check for the extended capabilities if the discovered config size is more than 256 bytes. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-04-28vfio/pci: Add test for BAR restoreAlex Williamson
If a device is reset without the memory or i/o bits enabled in the command register we may not detect it, potentially leaving the device without valid BAR programming. Add an additional test to check the BARs on each write to the command register. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-04-28vfio/pci: Hide broken INTx support from userAlex Williamson
INTx masking has two components, the first is that we need the ability to prevent the device from continuing to assert INTx. This is provided via the DisINTx bit in the command register and is the only thing we can really probe for when testing if INTx masking is supported. The second component is that the device needs to indicate if INTx is asserted via the interrupt status bit in the device status register. With these two features we can generically determine if one of the devices we own is asserting INTx, signal the user, and mask the interrupt while the user services the device. Generally if one or both of these components is broken we resort to APIC level interrupt masking, which requires an exclusive interrupt since we have no way to determine the source of the interrupt in a shared configuration. This often makes it difficult or impossible to configure the system for userspace use of the device, for an interrupt mode that the user may not need. One possible configuration of broken INTx masking is that the DisINTx support is fully functional, but the interrupt status bit never signals interrupt assertion. In this case we do have the ability to prevent the device from asserting INTx, but lack the ability to identify the interrupt source. For this case we can simply pretend that the device lacks INTx support entirely, keeping DisINTx set on the physical device, virtualizing this bit for the user, and virtualizing the interrupt pin register to indicate no INTx support. We already support virtualization of the DisINTx bit and already virtualize the interrupt pin for platforms without INTx support. By tying these components together, setting DisINTx on open and reset, and identifying devices broken in this particular way, we can provide support for them w/o the handicap of APIC level INTx masking. Intel i40e (XL710/X710) 10/20/40GbE NICs have been identified as being broken in this specific way. We leave the vfio-pci.nointxmask option as a mechanism to bypass this support, enabling INTx on the device with all the requirements of APIC level masking. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Cc: John Ronciak <john.ronciak@intel.com> Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
2016-02-22vfio/pci: Expose shadow ROM as PCI option ROMAlex Williamson
Integrated graphics may have their ROM shadowed at 0xc0000 rather than implement a PCI option ROM. Make this ROM appear to the user using the ROM BAR. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>