kernel/linux.git/drivers/s390/cio, branch v6.19.12

s390/cio: Fix device lifecycle handling in css_alloc_subchannel()

2026-02-26T23:00:44+00:00

[ Upstream commit f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7 ] `css_alloc_subchannel()` calls `device_initialize()` before setting up the DMA masks. If `dma_set_coherent_mask()` or `dma_set_mask()` fails, the error path frees the subchannel structure directly, bypassing the device model reference counting. Once `device_initialize()` has been called, the embedded struct device must be released via `put_device()`, allowing the release callback to free the container structure. Fix the error path by dropping the initial device reference with `put_device()` instead of calling `kfree()` directly. This ensures correct device lifetime handling and avoids potential use-after-free or double-free issues. Fixes: e5dcf0025d7af ("s390/css: move subchannel lock allocation") Signed-off-by: Salah Triki Reviewed-by: Vineeth Vijayan Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

Merge tag 'vfio-v6.19-rc1' of https://github.com/awilliam/linux-vfio

2025-12-05T02:42:48+00:00

Pull VFIO updates from Alex Williamson: - Move libvfio selftest artifacts in preparation of more tightly coupled integration with KVM selftests (David Matlack) - Fix comment typo in mtty driver (Chu Guangqing) - Support for new hardware revision in the hisi_acc vfio-pci variant driver where the migration registers can now be accessed via the PF. When enabled for this support, the full BAR can be exposed to the user (Longfang Liu) - Fix vfio cdev support for VF token passing, using the correct size for the kernel structure, thereby actually allowing userspace to provide a non-zero UUID token. Also set the match token callback for the hisi_acc, fixing VF token support for this this vfio-pci variant driver (Raghavendra Rao Ananta) - Introduce internal callbacks on vfio devices to simplify and consolidate duplicate code for generating VFIO_DEVICE_GET_REGION_INFO data, removing various ioctl intercepts with a more structured solution (Jason Gunthorpe) - Introduce dma-buf support for vfio-pci devices, allowing MMIO regions to be exposed through dma-buf objects with lifecycle managed through move operations. This enables low-level interactions such as a vfio-pci based SPDK drivers interacting directly with dma-buf capable RDMA devices to enable peer-to-peer operations. IOMMUFD is also now able to build upon this support to fill a long standing feature gap versus the legacy vfio type1 IOMMU backend with an implementation of P2P support for VM use cases that better manages the lifecycle of the P2P mapping (Leon Romanovsky, Jason Gunthorpe, Vivek Kasireddy) - Convert eventfd triggering for error and request signals to use RCU mechanisms in order to avoid a 3-way lockdep reported deadlock issue (Alex Williamson) - Fix a 32-bit overflow introduced via dma-buf support manifesting with large DMA buffers (Alex Mastro) - Convert nvgrace-gpu vfio-pci variant driver to insert mappings on fault rather than at mmap time. This conversion serves both to make use of huge PFNMAPs but also to both avoid corrected RAS events during reset by now being subject to vfio-pci-core's use of unmap_mapping_range(), and to enable a device readiness test after reset (Ankit Agrawal) - Refactoring of vfio selftests to support multi-device tests and split code to provide better separation between IOMMU and device objects. This work also enables a new test suite addition to measure parallel device initialization latency (David Matlack) * tag 'vfio-v6.19-rc1' of https://github.com/awilliam/linux-vfio: (65 commits) vfio: selftests: Add vfio_pci_device_init_perf_test vfio: selftests: Eliminate INVALID_IOVA vfio: selftests: Split libvfio.h into separate header files vfio: selftests: Move vfio_selftests_*() helpers into libvfio.c vfio: selftests: Rename vfio_util.h to libvfio.h vfio: selftests: Stop passing device for IOMMU operations vfio: selftests: Move IOVA allocator into iova_allocator.c vfio: selftests: Move IOMMU library code into iommu.c vfio: selftests: Rename struct vfio_dma_region to dma_region vfio: selftests: Upgrade driver logging to dev_err() vfio: selftests: Prefix logs with device BDF where relevant vfio: selftests: Eliminate overly chatty logging vfio: selftests: Support multiple devices in the same container/iommufd vfio: selftests: Introduce struct iommu vfio: selftests: Rename struct vfio_iommu_mode to iommu_mode vfio: selftests: Allow passing multiple BDFs on the command line vfio: selftests: Split run.sh into separate scripts vfio: selftests: Move run.sh into scripts directory vfio/nvgrace-gpu: wait for the GPU mem to be ready vfio/nvgrace-gpu: Inform devmem unmapped after reset ...

s390: Remove KMSG_COMPONENT macro

2025-11-24T10:45:21+00:00

The KMSG_COMPONENT macro is a leftover of the s390 specific "kernel message catalog" which never made it upstream. Remove the macro in order to get rid of a pointless indirection. Replace all users with the string it defines. In almost all cases this leads to a simple replacement like this: - #define KMSG_COMPONENT "appldata" - #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + #define pr_fmt(fmt) "appldata: " fmt Except for some special cases this is just mechanical/scripted work. Acked-by: Thomas Richter Signed-off-by: Heiko Carstens

s390: Remove compat support

2025-11-17T10:10:38+00:00

There shouldn't be any 31 bit code around anymore that matters. Remove the compat layer support required to run 31 bit code. Reason for removal is code simplification and reduced test effort. Note that this comes without any deprecation warnings added to config options, or kernel messages, since most likely those would be ignored anyway. If it turns out there is still a reason to keep the compat layer this can be reverted at any time in the future. Reviewed-by: Arnd Bergmann Signed-off-by: Heiko Carstens

vfio/ccw: Convert to get_region_info_caps

2025-11-12T22:05:03+00:00

Remove the duplicate code and flatten the call chain. Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe Reviewed-by: Eric Farman Link: https://lore.kernel.org/r/18-v2-2a9e24d62f1b+e10a-vfio_get_region_info_op_jgg@nvidia.com Signed-off-by: Alex Williamson

vfio/ccw: Provide a get_region_info op

2025-11-12T22:05:02+00:00

Move it out of vfio_ccw_mdev_ioctl() and re-indent it. Reviewed-by: Kevin Tian Signed-off-by: Jason Gunthorpe Reviewed-by: Eric Farman Link: https://lore.kernel.org/r/12-v2-2a9e24d62f1b+e10a-vfio_get_region_info_op_jgg@nvidia.com Signed-off-by: Alex Williamson

s390/cio: Use scnprintf() instead of sprintf()

2025-10-21T08:17:30+00:00

Use scnprintf() instead of sprintf() for those cases where the destination is an array and the size of the array is known at compile time. This prevents theoretical buffer overflows, but also avoids that people again and again spend time to figure out if the code is actually safe. Reviewed-by: Jan Polensky Signed-off-by: Heiko Carstens

s390/cio: Update purge function to unregister the unused subchannels

2025-10-04T16:40:42+00:00

Starting with 'commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")', cio no longer unregisters subchannels when the attached device is invalid or unavailable. As an unintended side-effect, the cio_ignore purge function no longer removes subchannels for devices on the cio_ignore list if no CCW device is attached. This situation occurs when a CCW device is non-operational or unavailable To ensure the same outcome of the purge function as when the current cio_ignore list had been active during boot, update the purge function to remove I/O subchannels without working CCW devices if the associated device number is found on the cio_ignore list. Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") Suggested-by: Peter Oberparleiter Reviewed-by: Peter Oberparleiter Signed-off-by: Vineeth Vijayan Signed-off-by: Heiko Carstens

s390: Remove superfluous newlines from inline assemblies

2025-09-29T11:52:08+00:00

Remove superfluous newlines from inline assemblies. Compilers use the number of lines of inline assemblies as heuristic for the complexity and inline decisions. Therefore inline assemblies should only contain as many lines as required. A lot of inline assemblies contain a superfluous newline for the last line. Remove such newlines to improve compiler inlining decisions. Suggested-by: Juergen Christ Signed-off-by: Heiko Carstens Reviewed-by: Alexander Gordeev Reviewed-by: Juergen Christ Signed-off-by: Alexander Gordeev

s390/cio/ioasm: Fix __xsch() condition code handling

2025-09-29T11:52:08+00:00

For the __xsch() inline assembly the conversion to flag output macros is incomplete. Only the conditional shift of the return value was added, while the required changes to the inline assembly itself are missing. If compiled with GCC versions before 14.2 this leads to a double shift of the cc output operand and therefore the returned value of __xsch() is incorrectly always zero, instead of the expected condition code. Fixes: e200565d434b ("s390/cio/ioasm: Convert to use flag output macros") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens Acked-by: Alexander Gordeev Reviewed-by: Juergen Christ Signed-off-by: Alexander Gordeev