kernel/linux.git/drivers/uio, branch v6.19.11

uio: pci_sva: correct '-ENODEV' check logic

2026-01-16T15:43:43+00:00

The current '-ENODEV' check uses '&&', which can lead to a NULL pointer dereference when udev is NULL. Fix the condition to return -ENODEV if either udev or its pdev is NULL. Fixes: 3397c3cd859a ("uio: Add SVA support for PCI devices via uio_pci_generic_sva.c") Signed-off-by: Haiyue Wang Link: https://patch.msgid.link/20260109175448.34309-1-haiyuewa@163.com Signed-off-by: Greg Kroah-Hartman

treewide: Update email address

2026-01-11T16:09:11+00:00

In a vain attempt to consolidate the email zoo switch everything to the kernel.org account. Signed-off-by: Thomas Gleixner Signed-off-by: Linus Torvalds

uio: Add SVA support for PCI devices via uio_pci_generic_sva.c

2025-11-26T14:10:39+00:00

This patch introduces a new UIO driver, uio_pci_generic_sva, which extends the functionality of uio_pci_generic by adding support for Shared Virtual Addressing (SVA) when IOMMU is enabled in the system. The key enhancement allows PCI devices to directly use user-space virtual addresses for DMA operations, eliminating the need for bounce buffers or explicit IOVA mapping. This is achieved by leveraging the kernel's IOMMU-SVA subsystem, including process address space attachment, page fault handling, and shared context management between CPU and device. With this driver, userspace applications can perform zero-copy DMA using native pointers: void *addr = malloc(N); set_dma_addr((uint64_t)addr); // Passing user VA directly start_dma(); The device can now access 'addr' through the IOMMU's PASID-based translation, provided that the underlying IOMMU hardware (e.g., Intel VT-d 3.1+, AMD-Vi, ARM SMMU, RISCV IOMMU) and platform support SVA. Dependencies: - CONFIG_IOMMU_SVA must be enabled. - The platform must support PRI (Page Request Interface) and PASID. - Device drivers/userspace must handle page faults if demand-paging is used. The implementation reuses core logic from uio_pci_generic.c while adding PASID setting, and integration with the IOMMU SVA APIs. Also, add a read-only sysfs attribute 'pasid' to expose the Process Address Space ID assigned by IOMMU driver when binding an SVA-enabled device. For details, refer to the ABI documentation for uio_pci_sva driver sysfs attribute (Documentation/ABI/testing/sysfs-driver-uio_pci_sva-pasid). Signed-off-by: Yaxing Guo Link: https://patch.msgid.link/20250926095828.506-1-guoyaxing@bosc.ac.cn Signed-off-by: Greg Kroah-Hartman

uio: uio_fsl_elbc_gpcm:: Add null pointer check to uio_fsl_elbc_gpcm_probe

2025-10-22T06:00:02+00:00

devm_kasprintf() returns a pointer to dynamically allocated memory which can be NULL upon failure. Fixes: d57801c45f53e ("uio: uio_fsl_elbc_gpcm: use device-managed allocators") Signed-off-by: Li Qiang Link: https://patch.msgid.link/20251015064020.56589-1-liqiang01@kylinos.cn Signed-off-by: Greg Kroah-Hartman

Merge tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2025-10-07T15:40:15+00:00

Pull hyperv updates from Wei Liu: - Unify guest entry code for KVM and MSHV (Sean Christopherson) - Switch Hyper-V MSI domain to use msi_create_parent_irq_domain() (Nam Cao) - Add CONFIG_HYPERV_VMBUS and limit the semantics of CONFIG_HYPERV (Mukesh Rathor) - Add kexec/kdump support on Azure CVMs (Vitaly Kuznetsov) - Deprecate hyperv_fb in favor of Hyper-V DRM driver (Prasanna Kumar T S M) - Miscellaneous enhancements, fixes and cleanups (Abhishek Tiwari, Alok Tiwari, Nuno Das Neves, Wei Liu, Roman Kisel, Michael Kelley) * tag 'hyperv-next-signed-20251006' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hyperv: Remove the spurious null directive line MAINTAINERS: Mark hyperv_fb driver Obsolete fbdev/hyperv_fb: deprecate this in favor of Hyper-V DRM driver Drivers: hv: Make CONFIG_HYPERV bool Drivers: hv: Add CONFIG_HYPERV_VMBUS option Drivers: hv: vmbus: Fix typos in vmbus_drv.c Drivers: hv: vmbus: Fix sysfs output format for ring buffer index Drivers: hv: vmbus: Clean up sscanf format specifier in target_cpu_store() x86/hyperv: Switch to msi_create_parent_irq_domain() mshv: Use common "entry virt" APIs to do work in root before running guest entry: Rename "kvm" entry code assets to "virt" to genericize APIs entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper mshv: Handle NEED_RESCHED_LAZY before transferring to guest x86/hyperv: Add kexec/kdump support on Azure CVMs Drivers: hv: Simplify data structures for VMBus channel close message Drivers: hv: util: Cosmetic changes for hv_utils_transport.c mshv: Add support for a new parent partition configuration clocksource: hyper-v: Skip unnecessary checks for the root partition hyperv: Add missing field to hv_output_map_device_interrupt

Drivers: hv: Add CONFIG_HYPERV_VMBUS option

2025-10-01T00:00:42+00:00

At present VMBus driver is hinged off of CONFIG_HYPERV which entails lot of builtin code and encompasses too much. It's not always clear what depends on builtin hv code and what depends on VMBus. Setting CONFIG_HYPERV as a module and fudging the Makefile to switch to builtin adds even more confusion. VMBus is an independent module and should have its own config option. Also, there are scenarios like baremetal dom0/root where support is built in with CONFIG_HYPERV but without VMBus. Lastly, there are more features coming down that use CONFIG_HYPERV and add more dependencies on it. So, create a fine grained HYPERV_VMBUS option and update Kconfigs for dependency on VMBus. Signed-off-by: Mukesh Rathor Acked-by: Bjorn Helgaas # drivers/pci Signed-off-by: Wei Liu

uio_hv_generic: Let userspace take care of interrupt mask

2025-09-06T13:57:21+00:00

Remove the logic to set interrupt mask by default in uio_hv_generic driver as the interrupt mask value is supposed to be controlled completely by the user space. If the mask bit gets changed by the driver, concurrently with user mode operating on the ring, the mask bit may be set when it is supposed to be clear, and the user-mode driver will miss an interrupt which will cause a hang. For eg- when the driver sets inbound ring buffer interrupt mask to 1, the host does not interrupt the guest on the UIO VMBus channel. However, setting the mask does not prevent the host from putting a message in the inbound ring buffer. So let’s assume that happens, the host puts a message into the ring buffer but does not interrupt. Subsequently, the user space code in the guest sets the inbound ring buffer interrupt mask to 0, saying “Hey, I’m ready for interrupts”. User space code then calls pread() to wait for an interrupt. Then one of two things happens: * The host never sends another message. So the pread() waits forever. * The host does send another message. But because there’s already a message in the ring buffer, it doesn’t generate an interrupt. This is the correct behavior, because the host should only send an interrupt when the inbound ring buffer transitions from empty to not-empty. Adding an additional message to a ring buffer that is not empty is not supposed to generate an interrupt on the guest. Since the guest is waiting in pread() and not removing messages from the ring buffer, the pread() waits forever. This could be easily reproduced in hv_fcopy_uio_daemon if we delay setting interrupt mask to 0. Similarly if hv_uio_channel_cb() sets the interrupt_mask to 1, there’s a race condition. Once user space empties the inbound ring buffer, but before user space sets interrupt_mask to 0, the host could put another message in the ring buffer but it wouldn’t interrupt. Then the next pread() would hang. Fix these by removing all instances where interrupt_mask is changed, while keeping the one in set_event() unchanged to enable userspace control the interrupt mask by writing 0/1 to /dev/uioX. Fixes: 95096f2fbd10 ("uio-hv-generic: new userspace i/o driver for VMBus") Suggested-by: John Starks Signed-off-by: Naman Jain Cc: stable@vger.kernel.org Reviewed-by: Michael Kelley Reviewed-by: Long Li Reviewed-by: Tianyu Lan Tested-by: Tianyu Lan Link: https://lore.kernel.org/r/20250828044200.492030-1-namjain@linux.microsoft.com Signed-off-by: Greg Kroah-Hartman

uio: uio_pdrv_genirq: Remove dummy PM handling

2025-09-06T13:57:18+00:00

Since commit 63d00be69348fda4 ("PM: runtime: Allow unassigned ->runtime_suspend|resume callbacks"), unassigned .runtime_{suspend,resume}() callbacks are treated the same as dummy callbacks that just return zero. As the Runtime PM callbacks were the only driver-specific PM handling, all PM handling can be removed. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/a5495b6068dd4e40ae7e0fb66b067fd5b5c210b2.1756999260.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

uio: uio_dmem_genirq: Remove dummy PM handling

2025-09-06T13:57:15+00:00

Since commit 63d00be69348fda4 ("PM: runtime: Allow unassigned ->runtime_suspend|resume callbacks"), unassigned .runtime_{suspend,resume}() callbacks are treated the same as dummy callbacks that just return zero. As the Runtime PM callbacks were the only driver-specific PM handling, all PM handling can be removed. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/121921f66a2baa125ea62be9436e8b5b12a4ad4d.1756999182.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

uio: uio_pdrv_genirq: Remove MODULE_DEVICE_TABLE

2025-09-06T13:57:11+00:00

The struct of_device_id list here is filled in at load time since commit 05c3e0bb5629 ("UIO: allow binding uio_pdrv_genirq.c to devices using command line option"). However, this does not work with MODULE_DEVICE_TABLE, which generates an alias at build time. In this case, it generates the aliases "of:N*T*" and "of:N*T*C*", which matches *any* OF device node, which is obviously not intended. It confuses userspace into loading this module for any OF device, and confuses anyone trying to resolve an OF modalias. Remove this broken MODULE_DEVICE_TABLE. Suggested-by: Emily Fixes: 05c3e0bb5629 ("UIO: allow binding uio_pdrv_genirq.c to devices using command line option") Signed-off-by: Vivian Wang Link: https://lore.kernel.org/r/20250826-uio-no-modalias-v2-1-495afa9e8a5b@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman