C does not permit an initialiser expression on a variable-length array
(C99 Section 6.7.9 constraint: "The type of the entity to be initialized
shall not be a variable length array type").
vfio_pci_irq_set() declared:
u8 buf[sizeof(struct vfio_irq_set) + sizeof(int) * count] = {};
where `count` is a runtime function parameter, making `buf` a VLA.
GCC rejects this with (tried with GCC-9.4.0):
error: variable-sized object may not be initialized
Fix by removing the `= {}` initialiser and inserting an explicit
memset() immediately after the declaration. memset() on a VLA is
perfectly legal and achieves the same zero-initialisation on all
conforming C implementations.
Fixes: 19faf6fd96 ("vfio: selftests: Add a helper library for VFIO selftests")
Cc: stable@vger.kernel.org
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Manish Honap <mhonap@nvidia.com>
Link: https://lore.kernel.org/r/20260317051402.3725670-1-mhonap@nvidia.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Update vfio_pci_bar_map() to align BAR mmaps for efficient huge page
mappings. The manual mmap alignment can be removed once mmap(!MAP_FIXED)
on vfio device fds improves to automatically return well-aligned
addresses.
Also add MADV_HUGEPAGE, which encourages the kernel to use huge pages
(e.g. when /sys/kernel/mm/transparent_hugepage/enabled is set to "madvise").
Drop MAP_FILE from mmap(). It is an ignored compatibility flag.
Signed-off-by: Alex Mastro <amastro@fb.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Tested-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20260114-map-mmio-test-v3-2-44e036d95e64@fb.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Drop the <uapi/linux/types.h> includes now that <linux/types.h>
(tools/include/linux/types.h) has a definition for __aligned_le64, which
is needed by <linux/iommufd.h>.
Including <uapi/linux/types.h> is harmless but causes benign typedef
redefinitions. This is not a problem for VFIO selftests but becomes an
issue when the VFIO selftests library is built into KVM selftests, since
they are built with -std=gnu99 which does not allow typedef redifitions.
No functional change intended.
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20251219233818.1965306-3-dmatlack@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Pull non-MM updates from Andrew Morton:
- "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
fixes a build issue and does some cleanup in ib/sys_info.c
- "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
enhances the 64-bit math code on behalf of a PWM driver and beefs up
the test module for these library functions
- "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
makes BPF symbol names, sizes, and line numbers available to the GDB
debugger
- "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
adds a sysctl which can be used to cause additional info dumping when
the hung-task and lockup detectors fire
- "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
adds a general base64 encoder/decoder to lib/ and migrates several
users away from their private implementations
- "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
makes TCP a little faster
- "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
reworks the KEXEC Handover interfaces in preparation for Live Update
Orchestrator (LUO), and possibly for other future clients
- "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
increases the flexibility of KEXEC Handover. Also preparation for LUO
- "Live Update Orchestrator" (Pasha Tatashin)
is a major new feature targeted at cloud environments. Quoting the
cover letter:
This series introduces the Live Update Orchestrator, a kernel
subsystem designed to facilitate live kernel updates using a
kexec-based reboot. This capability is critical for cloud
environments, allowing hypervisors to be updated with minimal
downtime for running virtual machines. LUO achieves this by
preserving the state of selected resources, such as memory,
devices and their dependencies, across the kernel transition.
As a key feature, this series includes support for preserving
memfd file descriptors, which allows critical in-memory data, such
as guest RAM or any other large memory region, to be maintained in
RAM across the kexec reboot.
Mike Rappaport merits a mention here, for his extensive review and
testing work.
- "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
moves the kexec and kdump sysfs entries from /sys/kernel/ to
/sys/kernel/kexec/ and adds back-compatibility symlinks which can
hopefully be removed one day
- "kho: fixes for vmalloc restoration" (Mike Rapoport)
fixes a BUG which was being hit during KHO restoration of vmalloc()
regions
* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
calibrate: update header inclusion
Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
vmcoreinfo: track and log recoverable hardware errors
kho: fix restoring of contiguous ranges of order-0 pages
kho: kho_restore_vmalloc: fix initialization of pages array
MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
init: replace simple_strtoul with kstrtoul to improve lpj_setup
KHO: fix boot failure due to kmemleak access to non-PRESENT pages
Documentation/ABI: new kexec and kdump sysfs interface
Documentation/ABI: mark old kexec sysfs deprecated
kexec: move sysfs entries to /sys/kernel/kexec
test_kho: always print restore status
kho: free chunks using free_page() instead of kfree()
selftests/liveupdate: add kexec test for multiple and empty sessions
selftests/liveupdate: add simple kexec-based selftest for LUO
selftests/liveupdate: add userspace API selftests
docs: add documentation for memfd preservation via LUO
mm: memfd_luo: allow preserving memfd
liveupdate: luo_file: add private argument to store runtime state
mm: shmem: export some functions to internal.h
...
Move the IOVA allocator into its own file, to provide better separation
between the allocator and the struct vfio_pci_device helper code.
The allocator could go into iommu.c, but it is standalone enough that a
separate file seems cleaner. This also continues the trend of having a
.c for every major object in VFIO selftests (vfio_pci_device.c,
vfio_pci_driver.c, iommu.c, and now iova_allocator.c).
No functional change intended.
Reviewed-by: Alex Mastro <amastro@fb.com>
Tested-by: Alex Mastro <amastro@fb.com>
Reviewed-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20251126231733.3302983-13-dmatlack@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Rename struct vfio_dma_region to dma_region. This is in preparation for
separating the VFIO PCI device library code from the IOMMU library code.
This name change also better reflects the fact that DMA mappings can be
managed by either VFIO or IOMMUFD. i.e. the "vfio_" prefix is
misleading.
Reviewed-by: Alex Mastro <amastro@fb.com>
Tested-by: Alex Mastro <amastro@fb.com>
Reviewed-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20251126231733.3302983-11-dmatlack@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Support tests that want to add multiple devices to the same
container/iommufd by decoupling struct vfio_pci_device from
struct iommu.
Multi-devices tests can now put multiple devices in the same
container/iommufd like so:
iommu = iommu_init(iommu_mode);
device1 = vfio_pci_device_init(bdf1, iommu);
device2 = vfio_pci_device_init(bdf2, iommu);
device3 = vfio_pci_device_init(bdf3, iommu);
...
vfio_pci_device_cleanup(device3);
vfio_pci_device_cleanup(device2);
vfio_pci_device_cleanup(device1);
iommu_cleanup(iommu);
To account for the new separation of vfio_pci_device and iommu, update
existing tests to initialize and cleanup a struct iommu.
Reviewed-by: Alex Mastro <amastro@fb.com>
Tested-by: Alex Mastro <amastro@fb.com>
Reviewed-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20251126231733.3302983-7-dmatlack@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Add support for passing multiple device BDFs to a test via the command
line. This is a prerequisite for multi-device tests.
Single-device tests can continue using vfio_selftests_get_bdf(), which
will continue to return argv[argc - 1] (if it is a BDF string), or the
environment variable $VFIO_SELFTESTS_BDF otherwise.
For multi-device tests, a new helper called vfio_selftests_get_bdfs() is
introduced which will return an array of all BDFs found at the end of
argv[], as well as the number of BDFs found (passed back to the caller
via argument). The array of BDFs returned does not need to be freed by
the caller.
The environment variable VFIO_SELFTESTS_BDF continues to support only a
single BDF for the time being.
Reviewed-by: Alex Mastro <amastro@fb.com>
Tested-by: Alex Mastro <amastro@fb.com>
Reviewed-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20251126231733.3302983-4-dmatlack@google.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
VFIO selftests need to map IOVAs from legally accessible ranges, which
could vary between hardware. Tests in vfio_dma_mapping_test.c are making
excessively strong assumptions about which IOVAs can be mapped.
Add vfio_iommu_iova_ranges(), which queries IOVA ranges from the
IOMMUFD or VFIO container associated with the device. The queried ranges
are normalized to IOMMUFD's iommu_iova_range representation so that
handling of IOVA ranges up the stack can be implementation-agnostic.
iommu_iova_range and vfio_iova_range are equivalent, so bias to using the
new interface's struct.
Query IOMMUFD's ranges with IOMMU_IOAS_IOVA_RANGES.
Query VFIO container's ranges with VFIO_IOMMU_GET_INFO and
VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE.
The underlying vfio_iommu_type1_info buffer-related functionality has
been kept generic so the same helpers can be used to query other
capability chain information, if needed.
Reviewed-by: David Matlack <dmatlack@google.com>
Tested-by: David Matlack <dmatlack@google.com>
Signed-off-by: Alex Mastro <amastro@fb.com>
Link: https://lore.kernel.org/r/20251111-iova-ranges-v3-1-7960244642c5@fb.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Add __vfio_pci_dma_*() helpers which return -errno from the underlying
ioctls.
Add __vfio_pci_dma_unmap_all() to test more unmapping code paths. Add an
out unmapped arg to report the unmapped byte size.
The existing vfio_pci_dma_*() functions, which are intended for
happy-path usage (assert on failure) are now thin wrappers on top of the
double-underscore helpers.
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Alex Mastro <amastro@fb.com>
Link: https://lore.kernel.org/r/20251028-fix-unmap-v6-4-2542b96bcc8e@fb.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
Add a driver framework to VFIO selftests, so that devices can generate
DMA and interrupts in a common way that can be then utilized by tests.
This will enable VFIO selftests to exercise real hardware DMA and
interrupt paths, without needing any device-specific code in the test
itself.
Subsequent commits will introduce drivers for specific devices.
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-13-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add a basic helper library to be used by VFIO selftests.
The basic unit of the library is struct vfio_pci_device, which
represents a single PCI device that is bound to the vfio-pci driver. The
library currently only supports a single device per group and container,
and VFIO IOMMU types.
The code in this library was heavily based on prior work done by
Raghavendra Rao Ananta <rananta@google.com>, and the VFIO_ASSERT*()
macros were written by Vipin Sharma <vipinsh@google.com>.
Separate that Makefile rules for building the library into a separate
script so that the library can be built by and linked into KVM selftests
in a subsequent commit.
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: David Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20250822212518.4156428-3-dmatlack@google.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
