The kernel has recently added support for shadow stacks, currently
x86 only using their CET feature but both arm64 and RISC-V have
equivalent features (GCS and Zicfiss respectively), I am actively
working on GCS[1]. With shadow stacks the hardware maintains an
additional stack containing only the return addresses for branch
instructions which is not generally writeable by userspace and ensures
that any returns are to the recorded addresses. This provides some
protection against ROP attacks and making it easier to collect call
stacks. These shadow stacks are allocated in the address space of the
userspace process.
Our API for shadow stacks does not currently offer userspace any
flexiblity for managing the allocation of shadow stacks for newly
created threads, instead the kernel allocates a new shadow stack with
the same size as the normal stack whenever a thread is created with the
feature enabled. The stacks allocated in this way are freed by the
kernel when the thread exits or shadow stacks are disabled for the
thread. This lack of flexibility and control isn't ideal, in the vast
majority of cases the shadow stack will be over allocated and the
implicit allocation and deallocation is not consistent with other
interfaces. As far as I can tell the interface is done in this manner
mainly because the shadow stack patches were in development since before
clone3() was implemented.
Since clone3() is readily extensible let's add support for specifying a
shadow stack when creating a new thread or process, keeping the current
implicit allocation behaviour if one is not specified either with
clone3() or through the use of clone(). The user must provide a shadow
stack pointer, this must point to memory mapped for use as a shadow
stackby map_shadow_stack() with an architecture specified shadow stack
token at the top of the stack.
Yuri Khrustalev has raised questions from the libc side regarding
discoverability of extended clone3() structure sizes[2], this seems like
a general issue with clone3(). There was a suggestion to add a hwcap on
arm64 which isn't ideal but is doable there, though architecture
specific mechanisms would also be needed for x86 (and RISC-V if it's
support gets merged before this does). The idea has, however, had
strong pushback from the architecture maintainers and it is possible to
detect support for this in clone3() by attempting a call with a
misaligned shadow stack pointer specified so no hwcap has been added.
[1] https://lore.kernel.org/linux-arm-kernel/20241001-arm64-gcs-v13-0-222b78d87…
[2] https://lore.kernel.org/r/aCs65ccRQtJBnZ_5@arm.com
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v18:
- Rebase onto v6.16-rc3.
- Thanks to pointers from Yuri Khrustalev this version has been tested
on x86 so I have removed the RFT tag.
- Clarify clone3_shadow_stack_valid() comment about the Kconfig check.
- Remove redundant GCSB DSYNCs in arm64 code.
- Fix token validation on x86.
- Link to v17: https://lore.kernel.org/r/20250609-clone3-shadow-stack-v17-0-8840ed97ff6f@k…
Changes in v17:
- Rebase onto v6.16-rc1.
- Link to v16: https://lore.kernel.org/r/20250416-clone3-shadow-stack-v16-0-2ffc9ca3917b@k…
Changes in v16:
- Rebase onto v6.15-rc2.
- Roll in fixes from x86 testing from Rick Edgecombe.
- Rework so that the argument is shadow_stack_token.
- Link to v15: https://lore.kernel.org/r/20250408-clone3-shadow-stack-v15-0-3fa245c6e3be@k…
Changes in v15:
- Rebase onto v6.15-rc1.
- Link to v14: https://lore.kernel.org/r/20250206-clone3-shadow-stack-v14-0-805b53af73b9@k…
Changes in v14:
- Rebase onto v6.14-rc1.
- Link to v13: https://lore.kernel.org/r/20241203-clone3-shadow-stack-v13-0-93b89a81a5ed@k…
Changes in v13:
- Rebase onto v6.13-rc1.
- Link to v12: https://lore.kernel.org/r/20241031-clone3-shadow-stack-v12-0-7183eb8bee17@k…
Changes in v12:
- Add the regular prctl() to the userspace API document since arm64
support is queued in -next.
- Link to v11: https://lore.kernel.org/r/20241005-clone3-shadow-stack-v11-0-2a6a2bd6d651@k…
Changes in v11:
- Rebase onto arm64 for-next/gcs, which is based on v6.12-rc1, and
integrate arm64 support.
- Rework the interface to specify a shadow stack pointer rather than a
base and size like we do for the regular stack.
- Link to v10: https://lore.kernel.org/r/20240821-clone3-shadow-stack-v10-0-06e8797b9445@k…
Changes in v10:
- Integrate fixes & improvements for the x86 implementation from Rick
Edgecombe.
- Require that the shadow stack be VM_WRITE.
- Require that the shadow stack base and size be sizeof(void *) aligned.
- Clean up trailing newline.
- Link to v9: https://lore.kernel.org/r/20240819-clone3-shadow-stack-v9-0-962d74f99464@ke…
Changes in v9:
- Pull token validation earlier and report problems with an error return
to parent rather than signal delivery to the child.
- Verify that the top of the supplied shadow stack is VM_SHADOW_STACK.
- Rework token validation to only do the page mapping once.
- Drop no longer needed support for testing for signals in selftest.
- Fix typo in comments.
- Link to v8: https://lore.kernel.org/r/20240808-clone3-shadow-stack-v8-0-0acf37caf14c@ke…
Changes in v8:
- Fix token verification with user specified shadow stack.
- Don't track user managed shadow stacks for child processes.
- Link to v7: https://lore.kernel.org/r/20240731-clone3-shadow-stack-v7-0-a9532eebfb1d@ke…
Changes in v7:
- Rebase onto v6.11-rc1.
- Typo fixes.
- Link to v6: https://lore.kernel.org/r/20240623-clone3-shadow-stack-v6-0-9ee7783b1fb9@ke…
Changes in v6:
- Rebase onto v6.10-rc3.
- Ensure we don't try to free the parent shadow stack in error paths of
x86 arch code.
- Spelling fixes in userspace API document.
- Additional cleanups and improvements to the clone3() tests to support
the shadow stack tests.
- Link to v5: https://lore.kernel.org/r/20240203-clone3-shadow-stack-v5-0-322c69598e4b@ke…
Changes in v5:
- Rebase onto v6.8-rc2.
- Rework ABI to have the user allocate the shadow stack memory with
map_shadow_stack() and a token.
- Force inlining of the x86 shadow stack enablement.
- Move shadow stack enablement out into a shared header for reuse by
other tests.
- Link to v4: https://lore.kernel.org/r/20231128-clone3-shadow-stack-v4-0-8b28ffe4f676@ke…
Changes in v4:
- Formatting changes.
- Use a define for minimum shadow stack size and move some basic
validation to fork.c.
- Link to v3: https://lore.kernel.org/r/20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@ke…
Changes in v3:
- Rebase onto v6.7-rc2.
- Remove stale shadow_stack in internal kargs.
- If a shadow stack is specified unconditionally use it regardless of
CLONE_ parameters.
- Force enable shadow stacks in the selftest.
- Update changelogs for RISC-V feature rename.
- Link to v2: https://lore.kernel.org/r/20231114-clone3-shadow-stack-v2-0-b613f8681155@ke…
Changes in v2:
- Rebase onto v6.7-rc1.
- Remove ability to provide preallocated shadow stack, just specify the
desired size.
- Link to v1: https://lore.kernel.org/r/20231023-clone3-shadow-stack-v1-0-d867d0b5d4d0@ke…
---
Mark Brown (8):
arm64/gcs: Return a success value from gcs_alloc_thread_stack()
Documentation: userspace-api: Add shadow stack API documentation
selftests: Provide helper header for shadow stack testing
fork: Add shadow stack support to clone3()
selftests/clone3: Remove redundant flushes of output streams
selftests/clone3: Factor more of main loop into test_clone3()
selftests/clone3: Allow tests to flag if -E2BIG is a valid error code
selftests/clone3: Test shadow stack support
Documentation/userspace-api/index.rst | 1 +
Documentation/userspace-api/shadow_stack.rst | 44 +++++
arch/arm64/include/asm/gcs.h | 8 +-
arch/arm64/kernel/process.c | 8 +-
arch/arm64/mm/gcs.c | 55 +++++-
arch/x86/include/asm/shstk.h | 11 +-
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/shstk.c | 53 ++++-
include/asm-generic/cacheflush.h | 11 ++
include/linux/sched/task.h | 17 ++
include/uapi/linux/sched.h | 9 +-
kernel/fork.c | 93 +++++++--
tools/testing/selftests/clone3/clone3.c | 226 ++++++++++++++++++----
tools/testing/selftests/clone3/clone3_selftests.h | 65 ++++++-
tools/testing/selftests/ksft_shstk.h | 98 ++++++++++
15 files changed, 620 insertions(+), 81 deletions(-)
---
base-commit: 86731a2a651e58953fc949573895f2fa6d456841
change-id: 20231019-clone3-shadow-stack-15d40d2bf536
Best regards,
--
Mark Brown <broonie(a)kernel.org>
Currently testing of userspace and in-kernel API use two different
frameworks. kselftests for the userspace ones and Kunit for the
in-kernel ones. Besides their different scopes, both have different
strengths and limitations:
Kunit:
* Tests are normal kernel code.
* They use the regular kernel toolchain.
* They can be packaged and distributed as modules conveniently.
Kselftests:
* Tests are normal userspace code
* They need a userspace toolchain.
A kernel cross toolchain is likely not enough.
* A fair amout of userland is required to run the tests,
which means a full distro or handcrafted rootfs.
* There is no way to conveniently package and run kselftests with a
given kernel image.
* The kselftests makefiles are not as powerful as regular kbuild.
For example they are missing proper header dependency tracking or more
complex compiler option modifications.
Therefore kunit is much easier to run against different kernel
configurations and architectures.
This series aims to combine kselftests and kunit, avoiding both their
limitations. It works by compiling the userspace kselftests as part of
the regular kernel build, embedding them into the kunit kernel or module
and executing them from there. If the kernel toolchain is not fit to
produce userspace because of a missing libc, the kernel's own nolibc can
be used instead.
The structured TAP output from the kselftest is integrated into the
kunit KTAP output transparently, the kunit parser can parse the combined
logs together.
Further room for improvements:
* Call each test in its completely dedicated namespace
* Handle additional test files besides the test executable through
archives. CPIO, cramfs, etc.
* Compatibility with kselftest_harness.h (in progress)
* Expose the blobs in debugfs
* Provide some convience wrappers around compat userprogs
* Figure out a migration path/coexistence solution for
kunit UAPI and tools/testing/selftests/
Output from the kunit example testcase, note the output of
"example_uapi_tests".
$ ./tools/testing/kunit/kunit.py run --kunitconfig lib/kunit example
...
Running tests with:
$ .kunit/linux kunit.filter_glob=example kunit.enable=1 mem=1G console=tty kunit_shutdown=halt
[11:53:53] ================== example (10 subtests) ===================
[11:53:53] [PASSED] example_simple_test
[11:53:53] [SKIPPED] example_skip_test
[11:53:53] [SKIPPED] example_mark_skipped_test
[11:53:53] [PASSED] example_all_expect_macros_test
[11:53:53] [PASSED] example_static_stub_test
[11:53:53] [PASSED] example_static_stub_using_fn_ptr_test
[11:53:53] [PASSED] example_priv_test
[11:53:53] =================== example_params_test ===================
[11:53:53] [SKIPPED] example value 3
[11:53:53] [PASSED] example value 2
[11:53:53] [PASSED] example value 1
[11:53:53] [SKIPPED] example value 0
[11:53:53] =============== [PASSED] example_params_test ===============
[11:53:53] [PASSED] example_slow_test
[11:53:53] ======================= (4 subtests) =======================
[11:53:53] [PASSED] procfs
[11:53:53] [PASSED] userspace test 2
[11:53:53] [SKIPPED] userspace test 3: some reason
[11:53:53] [PASSED] userspace test 4
[11:53:53] ================ [PASSED] example_uapi_test ================
[11:53:53] ===================== [PASSED] example =====================
[11:53:53] ============================================================
[11:53:53] Testing complete. Ran 16 tests: passed: 11, skipped: 5
[11:53:53] Elapsed time: 67.543s total, 1.823s configuring, 65.655s building, 0.058s running
Based on v6.16-rc1.
Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
---
Changes in v5:
- Initialize output variable of kernel_wait()
- Fix .incbin with in-tree builds
- Keep requirement of KTAP tests to have a number which was removed accidentally
- Only synthesize KTAP subtest failure if the outer one is TestStatus.FAILURE
- Use -I instead of -isystem in NOLIBC_USERCFLAGS to populate dependency files
- +To filesystem developers to all patches
- +To Luis Chamberlain for discussions about usage of usermodehelper
(see patches 6 and 12)
- Link to v4: https://lore.kernel.org/r/20250626-kunit-kselftests-v4-0-48760534fef5@linut…
Changes in v4:
- Move Kconfig.nolibc from tools/ to init/
- Drop generic userprogs nolibc integration
- Drop generic blob framework
- Pick up review tags from David
- Extend new kunit TAP parser tests
- Add MAINTAINERS entry
- Allow CONFIG_KUNIT_UAPI=m
- Split /proc validation into dedicated UAPI test
- Trim recipient list a bit
- Use KUNIT_FAIL_AND_ABORT() over KUNIT_FAIL()
- Link to v3: https://lore.kernel.org/r/20250611-kunit-kselftests-v3-0-55e3d148cbc6@linut…
Changes in v3:
- Reintroduce CONFIG_CC_CAN_LINK_STATIC
- Enable CONFIG_ARCH_HAS_NOLIBC for m68k and SPARC
- Properly handle 'clean' target for userprogs
- Use ramfs over tmpfs to reduce dependencies
- Inherit userprogs byte order and ABI from kernel
- Drop now unnecessary "#ifndef NOLIBC"
- Pick up review tags
- Drop usage of __private in blob.h,
sparse complains and it is not really necessary
- Fix execution on loongarch when using clang
- Drop userprogs libgcc handling, it was ugly and is not yet necessary
- Link to v2: https://lore.kernel.org/r/20250407-kunit-kselftests-v2-0-454114e287fd@linut…
Changes in v2:
- Rebase onto v6.15-rc1
- Add documentation and kernel docs
- Resolve invalid kconfig breakages
- Drop already applied patch "kbuild: implement CONFIG_HEADERS_INSTALL for Usermode Linux"
- Drop userprogs CONFIG_WERROR integration, it doesn't need to be part of this series
- Replace patch prefix "kconfig" with "kbuild"
- Rename kunit_uapi_run_executable() to kunit_uapi_run_kselftest()
- Generate private, conflict-free symbols in the blob framework
- Handle kselftest exit codes
- Handle SIGABRT
- Forward output also to kunit debugfs log
- Install a fd=0 stdin filedescriptor
- Link to v1: https://lore.kernel.org/r/20250217-kunit-kselftests-v1-0-42b4524c3b0a@linut…
---
Thomas Weißschuh (15):
kbuild: userprogs: avoid duplication of flags inherited from kernel
kbuild: userprogs: also inherit byte order and ABI from kernel
kbuild: doc: add label for userprogs section
init: re-add CONFIG_CC_CAN_LINK_STATIC
init: add nolibc build support
fs,fork,exit: export symbols necessary for KUnit UAPI support
kunit: tool: Add test for nested test result reporting
kunit: tool: Don't overwrite test status based on subtest counts
kunit: tool: Parse skipped tests from kselftest.h
kunit: Always descend into kunit directory during build
kunit: qemu_configs: loongarch: Enable LSX/LSAX
kunit: Introduce UAPI testing framework
kunit: uapi: Add example for UAPI tests
kunit: uapi: Introduce preinit executable
kunit: uapi: Validate usability of /proc
Documentation/dev-tools/kunit/api/index.rst | 5 +
Documentation/dev-tools/kunit/api/uapi.rst | 14 +
Documentation/kbuild/makefiles.rst | 2 +
MAINTAINERS | 11 +
Makefile | 7 +-
fs/exec.c | 2 +
fs/file.c | 1 +
fs/filesystems.c | 2 +
fs/fs_struct.c | 1 +
fs/pipe.c | 2 +
include/kunit/uapi.h | 77 ++++++
init/Kconfig | 7 +
init/Kconfig.nolibc | 15 +
init/Makefile.nolibc | 13 +
kernel/exit.c | 3 +
kernel/fork.c | 2 +
lib/Makefile | 4 -
lib/kunit/Kconfig | 14 +
lib/kunit/Makefile | 30 +-
lib/kunit/kunit-example-test.c | 15 +
lib/kunit/kunit-example-uapi.c | 22 ++
lib/kunit/kunit-test-uapi.c | 51 ++++
lib/kunit/kunit-test.c | 23 +-
lib/kunit/kunit-uapi.c | 305 +++++++++++++++++++++
lib/kunit/uapi-preinit.c | 63 +++++
tools/testing/kunit/kunit_parser.py | 11 +-
tools/testing/kunit/kunit_tool_test.py | 11 +
tools/testing/kunit/qemu_configs/loongarch.py | 2 +
.../test_is_test_passed-failure-nested.log | 10 +
.../test_data/test_is_test_passed-kselftest.log | 3 +-
30 files changed, 715 insertions(+), 13 deletions(-)
---
base-commit: 9d5898b413d17510b2a41664a42390a2c79f8bf4
change-id: 20241015-kunit-kselftests-56273bc40442
Best regards,
--
Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
This patchset introduces a new per-port bonding option: `ad_actor_port_prio`.
It allows users to configure the actor's port priority, which can then be used
by the bonding driver for aggregator selection based on port priority.
This provides finer control over LACP aggregator choice, especially in setups
with multiple eligible aggregators over 2 switches.
Hangbin Liu (3):
bonding: add support for per-port LACP actor priority
bonding: support aggregator selection based on port priority
selftests: bonding: add test for LACP actor port priority
Documentation/networking/bonding.rst | 18 ++++-
drivers/net/bonding/bond_3ad.c | 31 ++++++++
drivers/net/bonding/bond_netlink.c | 16 ++++
drivers/net/bonding/bond_options.c | 36 +++++++++
include/net/bond_3ad.h | 2 +
include/net/bond_options.h | 1 +
include/uapi/linux/if_link.h | 1 +
.../selftests/drivers/net/bonding/Makefile | 3 +-
.../drivers/net/bonding/bond_lacp_prio.sh | 73 +++++++++++++++++++
tools/testing/selftests/net/forwarding/lib.sh | 24 ------
tools/testing/selftests/net/lib.sh | 24 ++++++
11 files changed, 203 insertions(+), 26 deletions(-)
create mode 100755 tools/testing/selftests/drivers/net/bonding/bond_lacp_prio.sh
--
2.46.0
This series introduces NUMA-aware memory placement support for KVM guests
with guest_memfd memory backends. It builds upon Fuad Tabba's work that
enabled host-mapping for guest_memfd memory [1].
== Background ==
KVM's guest-memfd memory backend currently lacks support for NUMA policy
enforcement, causing guest memory allocations to be distributed across host
nodes according to kernel's default behavior, irrespective of any policy
specified by the VMM. This limitation arises because conventional userspace
NUMA control mechanisms like mbind(2) don't work since the memory isn't
directly mapped to userspace when allocations occur.
Fuad's work [1] provides the necessary mmap capability, and this series
leverages it to enable mbind(2).
== Implementation ==
This series implements proper NUMA policy support for guest-memfd by:
1. Adding mempolicy-aware allocation APIs to the filemap layer.
2. Introducing custom inodes (via a dedicated slab-allocated inode cache,
kvm_gmem_inode_info) to store NUMA policy and metadata for guest memory.
3. Implementing get/set_policy vm_ops in guest_memfd to support NUMA
policy.
With these changes, VMMs can now control guest memory placement by mapping
guest_memfd file descriptor and using mbind(2) to specify:
- Policy modes: default, bind, interleave, or preferred
- Host NUMA nodes: List of target nodes for memory allocation
These Policies affect only future allocations and do not migrate existing
memory. This matches mbind(2)'s default behavior which affects only new
allocations unless overridden with MPOL_MF_MOVE/MPOL_MF_MOVE_ALL flags (Not
supported for guest_memfd as it is unmovable by design).
== Upstream Plan ==
Phased approach as per David's guest_memfd extension overview [2] and
community calls [3]:
Phase 1 (this series):
1. Focuses on shared guest_memfd support (non-CoCo VMs).
2. Builds on Fuad's host-mapping work.
Phase2 (future work):
1. NUMA support for private guest_memfd (CoCo VMs).
2. Depends on SNP in-place conversion support [4].
This series provides a clean integration path for NUMA-aware memory
management for guest_memfd and lays the groundwork for future confidential
computing NUMA capabilities.
Please review and provide feedback!
Thanks,
Shivank
== Changelog ==
- v1,v2: Extended the KVM_CREATE_GUEST_MEMFD IOCTL to pass mempolicy.
- v3: Introduced fbind() syscall for VMM memory-placement configuration.
- v4-v6: Current approach using shared_policy support and vm_ops (based on
suggestions from David [5] and guest_memfd bi-weekly upstream
call discussion [6]).
- v7: Use inodes to store NUMA policy instead of file [7].
- v8: Rebase on top of Fuad's V12: Host mmaping for guest_memfd memory.
- v9: Rebase on top of Fuad's V13 and incorporate review comments
[1] https://lore.kernel.org/all/20250709105946.4009897-1-tabba@google.com
[2] https://lore.kernel.org/all/c1c9591d-218a-495c-957b-ba356c8f8e09@redhat.com
[3] https://docs.google.com/document/d/1M6766BzdY1Lhk7LiR5IqVR8B8mG3cr-cxTxOrAo…
[4] https://lore.kernel.org/all/20250613005400.3694904-1-michael.roth@amd.com
[5] https://lore.kernel.org/all/6fbef654-36e2-4be5-906e-2a648a845278@redhat.com
[6] https://lore.kernel.org/all/2b77e055-98ac-43a1-a7ad-9f9065d7f38f@amd.com
[7] https://lore.kernel.org/all/diqzbjumm167.fsf@ackerleytng-ctop.c.googlers.com
Ackerley Tng (1):
KVM: guest_memfd: Use guest mem inodes instead of anonymous inodes
Matthew Wilcox (Oracle) (2):
mm/filemap: Add NUMA mempolicy support to filemap_alloc_folio()
mm/filemap: Extend __filemap_get_folio() to support NUMA memory
policies
Shivank Garg (4):
mm/mempolicy: Export memory policy symbols
KVM: guest_memfd: Add slab-allocated inode cache
KVM: guest_memfd: Enforce NUMA mempolicy using shared policy
KVM: guest_memfd: selftests: Add tests for mmap and NUMA policy
support
fs/bcachefs/fs-io-buffered.c | 2 +-
fs/btrfs/compression.c | 4 +-
fs/btrfs/verity.c | 2 +-
fs/erofs/zdata.c | 2 +-
fs/f2fs/compress.c | 2 +-
include/linux/pagemap.h | 18 +-
include/uapi/linux/magic.h | 1 +
mm/filemap.c | 23 +-
mm/mempolicy.c | 6 +
mm/readahead.c | 2 +-
tools/testing/selftests/kvm/Makefile.kvm | 1 +
.../testing/selftests/kvm/guest_memfd_test.c | 122 ++++++++-
virt/kvm/guest_memfd.c | 255 ++++++++++++++++--
virt/kvm/kvm_main.c | 7 +-
virt/kvm/kvm_mm.h | 10 +-
15 files changed, 408 insertions(+), 49 deletions(-)
--
2.43.0
---
== Earlier Postings ==
v8: https://lore.kernel.org/all/20250618112935.7629-1-shivankg@amd.com
v7: https://lore.kernel.org/all/20250408112402.181574-1-shivankg@amd.com
v6: https://lore.kernel.org/all/20250226082549.6034-1-shivankg@amd.com
v5: https://lore.kernel.org/all/20250219101559.414878-1-shivankg@amd.com
v4: https://lore.kernel.org/all/20250210063227.41125-1-shivankg@amd.com
v3: https://lore.kernel.org/all/20241105164549.154700-1-shivankg@amd.com
v2: https://lore.kernel.org/all/20240919094438.10987-1-shivankg@amd.com
v1: https://lore.kernel.org/all/20240916165743.201087-1-shivankg@amd.com
The SBI Firmware Feature extension allows the S-mode to request some
specific features (either hardware or software) to be enabled. This
series uses this extension to request misaligned access exception
delegation to S-mode in order to let the kernel handle it. It also adds
support for the KVM FWFT SBI extension based on the misaligned access
handling infrastructure.
FWFT SBI extension is part of the SBI V3.0 specifications [1]. It can be
tested using the qemu provided at [2] which contains the series from
[3]. Upstream kvm-unit-tests can be used inside kvm to tests the correct
delegation of misaligned exceptions. Upstream OpenSBI can be used.
Note: Since SBI V3.0 is not yet ratified, FWFT extension API is split
between interface only and implementation, allowing to pick only the
interface which do not have hard dependencies on SBI.
The tests can be run using the kselftest from series [4].
$ qemu-system-riscv64 \
-cpu rv64,trap-misaligned-access=true,v=true \
-M virt \
-m 1024M \
-bios fw_dynamic.bin \
-kernel Image
...
# ./misaligned
TAP version 13
1..23
# Starting 23 tests from 1 test cases.
# RUN global.gp_load_lh ...
# OK global.gp_load_lh
ok 1 global.gp_load_lh
# RUN global.gp_load_lhu ...
# OK global.gp_load_lhu
ok 2 global.gp_load_lhu
# RUN global.gp_load_lw ...
# OK global.gp_load_lw
ok 3 global.gp_load_lw
# RUN global.gp_load_lwu ...
# OK global.gp_load_lwu
ok 4 global.gp_load_lwu
# RUN global.gp_load_ld ...
# OK global.gp_load_ld
ok 5 global.gp_load_ld
# RUN global.gp_load_c_lw ...
# OK global.gp_load_c_lw
ok 6 global.gp_load_c_lw
# RUN global.gp_load_c_ld ...
# OK global.gp_load_c_ld
ok 7 global.gp_load_c_ld
# RUN global.gp_load_c_ldsp ...
# OK global.gp_load_c_ldsp
ok 8 global.gp_load_c_ldsp
# RUN global.gp_load_sh ...
# OK global.gp_load_sh
ok 9 global.gp_load_sh
# RUN global.gp_load_sw ...
# OK global.gp_load_sw
ok 10 global.gp_load_sw
# RUN global.gp_load_sd ...
# OK global.gp_load_sd
ok 11 global.gp_load_sd
# RUN global.gp_load_c_sw ...
# OK global.gp_load_c_sw
ok 12 global.gp_load_c_sw
# RUN global.gp_load_c_sd ...
# OK global.gp_load_c_sd
ok 13 global.gp_load_c_sd
# RUN global.gp_load_c_sdsp ...
# OK global.gp_load_c_sdsp
ok 14 global.gp_load_c_sdsp
# RUN global.fpu_load_flw ...
# OK global.fpu_load_flw
ok 15 global.fpu_load_flw
# RUN global.fpu_load_fld ...
# OK global.fpu_load_fld
ok 16 global.fpu_load_fld
# RUN global.fpu_load_c_fld ...
# OK global.fpu_load_c_fld
ok 17 global.fpu_load_c_fld
# RUN global.fpu_load_c_fldsp ...
# OK global.fpu_load_c_fldsp
ok 18 global.fpu_load_c_fldsp
# RUN global.fpu_store_fsw ...
# OK global.fpu_store_fsw
ok 19 global.fpu_store_fsw
# RUN global.fpu_store_fsd ...
# OK global.fpu_store_fsd
ok 20 global.fpu_store_fsd
# RUN global.fpu_store_c_fsd ...
# OK global.fpu_store_c_fsd
ok 21 global.fpu_store_c_fsd
# RUN global.fpu_store_c_fsdsp ...
# OK global.fpu_store_c_fsdsp
ok 22 global.fpu_store_c_fsdsp
# RUN global.gen_sigbus ...
[12797.988647] misaligned[618]: unhandled signal 7 code 0x1 at 0x0000000000014dc0 in misaligned[4dc0,10000+76000]
[12797.988990] CPU: 0 UID: 0 PID: 618 Comm: misaligned Not tainted 6.13.0-rc6-00008-g4ec4468967c9-dirty #51
[12797.989169] Hardware name: riscv-virtio,qemu (DT)
[12797.989264] epc : 0000000000014dc0 ra : 0000000000014d00 sp : 00007fffe165d100
[12797.989407] gp : 000000000008f6e8 tp : 0000000000095760 t0 : 0000000000000008
[12797.989544] t1 : 00000000000965d8 t2 : 000000000008e830 s0 : 00007fffe165d160
[12797.989692] s1 : 000000000000001a a0 : 0000000000000000 a1 : 0000000000000002
[12797.989831] a2 : 0000000000000000 a3 : 0000000000000000 a4 : ffffffffdeadbeef
[12797.989964] a5 : 000000000008ef61 a6 : 626769735f6e0000 a7 : fffffffffffff000
[12797.990094] s2 : 0000000000000001 s3 : 00007fffe165d838 s4 : 00007fffe165d848
[12797.990238] s5 : 000000000000001a s6 : 0000000000010442 s7 : 0000000000010200
[12797.990391] s8 : 000000000000003a s9 : 0000000000094508 s10: 0000000000000000
[12797.990526] s11: 0000555567460668 t3 : 00007fffe165d070 t4 : 00000000000965d0
[12797.990656] t5 : fefefefefefefeff t6 : 0000000000000073
[12797.990756] status: 0000000200004020 badaddr: 000000000008ef61 cause: 0000000000000006
[12797.990911] Code: 8793 8791 3423 fcf4 3783 fc84 c737 dead 0713 eef7 (c398) 0001
# OK global.gen_sigbus
ok 23 global.gen_sigbus
# PASSED: 23 / 23 tests passed.
# Totals: pass:23 fail:0 xfail:0 xpass:0 skip:0 error:0
With kvm-tools:
# lkvm run -k sbi.flat -m 128
Info: # lkvm run -k sbi.flat -m 128 -c 1 --name guest-97
Info: Removed ghost socket file "/root/.lkvm//guest-97.sock".
##########################################################################
# kvm-unit-tests
##########################################################################
... [test messages elided]
PASS: sbi: fwft: FWFT extension probing no error
PASS: sbi: fwft: get/set reserved feature 0x6 error == SBI_ERR_DENIED
PASS: sbi: fwft: get/set reserved feature 0x3fffffff error == SBI_ERR_DENIED
PASS: sbi: fwft: get/set reserved feature 0x80000000 error == SBI_ERR_DENIED
PASS: sbi: fwft: get/set reserved feature 0xbfffffff error == SBI_ERR_DENIED
PASS: sbi: fwft: misaligned_deleg: Get misaligned deleg feature no error
PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error
PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature invalid value error
PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error
PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 0
PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value no error
PASS: sbi: fwft: misaligned_deleg: Set misaligned deleg feature value 1
PASS: sbi: fwft: misaligned_deleg: Verify misaligned load exception trap in supervisor
SUMMARY: 50 tests, 2 unexpected failures, 12 skipped
This series is available at [5].
Link: https://github.com/riscv-non-isa/riscv-sbi-doc/releases/download/vv3.0-rc2/… [1]
Link: https://github.com/rivosinc/qemu/tree/dev/cleger/misaligned [2]
Link: https://lore.kernel.org/all/20241211211933.198792-3-fkonrad@amd.com/T/ [3]
Link: https://lore.kernel.org/linux-riscv/20250414123543.1615478-1-cleger@rivosin… [4]
Link: https://github.com/rivosinc/linux/tree/dev/cleger/fwft [5]
---
V8:
- Move misaligned_access_speed under CONFIG_RISCV_MISALIGNED and add a
separate commit for that.
V7:
- Fix ifdefery build problems
- Move sbi_fwft_is_supported with fwft_set_req struct
- Added Atish Reviewed-by
- Updated KVM vcpu cfg hedeleg value in set_delegation
- Changed SBI ETIME error mapping to ETIMEDOUT
- Fixed a few typo reported by Alok
V6:
- Rename FWFT interface to remove "_local"
- Fix test for MEDELEG values in KVM FWFT support
- Add __init for unaligned_access_init()
- Rebased on master
V5:
- Return ERANGE as mapping for SBI_ERR_BAD_RANGE
- Removed unused sbi_fwft_get()
- Fix kernel for sbi_fwft_local_set_cpumask()
- Fix indentation for sbi_fwft_local_set()
- Remove spurious space in kvm_sbi_fwft_ops.
- Rebased on origin/master
- Remove fixes commits and sent them as a separate series [4]
V4:
- Check SBI version 3.0 instead of 2.0 for FWFT presence
- Use long for kvm_sbi_fwft operation return value
- Init KVM sbi extension even if default_disabled
- Remove revert_on_fail parameter for sbi_fwft_feature_set().
- Fix comments for sbi_fwft_set/get()
- Only handle local features (there are no globals yet in the spec)
- Add new SBI errors to sbi_err_map_linux_errno()
V3:
- Added comment about kvm sbi fwft supported/set/get callback
requirements
- Move struct kvm_sbi_fwft_feature in kvm_sbi_fwft.c
- Add a FWFT interface
V2:
- Added Kselftest for misaligned testing
- Added get_user() usage instead of __get_user()
- Reenable interrupt when possible in misaligned access handling
- Document that riscv supports unaligned-traps
- Fix KVM extension state when an init function is present
- Rework SBI misaligned accesses trap delegation code
- Added support for CPU hotplugging
- Added KVM SBI reset callback
- Added reset for KVM SBI FWFT lock
- Return SBI_ERR_DENIED_LOCKED when LOCK flag is set
Clément Léger (14):
riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions
riscv: sbi: remove useless parenthesis
riscv: sbi: add new SBI error mappings
riscv: sbi: add FWFT extension interface
riscv: sbi: add SBI FWFT extension calls
riscv: misaligned: request misaligned exception from SBI
riscv: misaligned: use on_each_cpu() for scalar misaligned access
probing
riscv: misaligned: declare misaligned_access_speed under
CONFIG_RISCV_MISALIGNED
riscv: misaligned: move emulated access uniformity check in a function
riscv: misaligned: add a function to check misalign trap delegability
RISC-V: KVM: add SBI extension init()/deinit() functions
RISC-V: KVM: add SBI extension reset callback
RISC-V: KVM: add support for FWFT SBI extension
RISC-V: KVM: add support for SBI_FWFT_MISALIGNED_DELEG
arch/riscv/include/asm/cpufeature.h | 14 +-
arch/riscv/include/asm/kvm_host.h | 5 +-
arch/riscv/include/asm/kvm_vcpu_sbi.h | 12 +
arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 29 +++
arch/riscv/include/asm/sbi.h | 60 +++++
arch/riscv/include/uapi/asm/kvm.h | 1 +
arch/riscv/kernel/sbi.c | 81 ++++++-
arch/riscv/kernel/traps_misaligned.c | 112 ++++++++-
arch/riscv/kernel/unaligned_access_speed.c | 8 +-
arch/riscv/kvm/Makefile | 1 +
arch/riscv/kvm/vcpu.c | 4 +-
arch/riscv/kvm/vcpu_sbi.c | 54 +++++
arch/riscv/kvm/vcpu_sbi_fwft.c | 257 +++++++++++++++++++++
arch/riscv/kvm/vcpu_sbi_sta.c | 3 +-
14 files changed, 620 insertions(+), 21 deletions(-)
create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
create mode 100644 arch/riscv/kvm/vcpu_sbi_fwft.c
--
2.49.0
Hi all,
This patch series addresses false positives in the generic mm selftests
and skips tests that cannot run correctly due to missing features or system
limitations.
v2: https://lore.kernel.org/all/20250703060656.54345-1-aboorvad@linux.ibm.com/
Changes in v3:
- Rebased onto the latest mm-new branch, top commit of the base is commit 0709ddf8951f ("mm: add zblock allocator").
- Minor refactor based on the review comments.
- Included the tags from the previous version.
---
v1: https://lore.kernel.org/all/20250616160632.35250-1-aboorvad@linux.ibm.com/
Changes in v2:
- Rebased onto the mm-new branch, top commit of the base is commit 3b4a8ad89f7e ("mm: add zblock allocator").
- Split some patches for clarity.
- Updated virtual_address_range test to support testing 4PB VA on PPC64.
- Added proper Fixes: tags.
- Included a patch to skip a failing userfaultfd test when unsupported,
instead of reporting a failure.
---
Please let us know if you have any further comments.
Thanks,
Aboorva
Aboorva Devarajan (3):
selftests/mm: Fix child process exit codes in ksm_functional_tests
selftests/mm: Skip thuge-gen test if system is not setup properly
selftests/mm: Skip hugepage-mremap test if userfaultfd unavailable
Donet Tom (4):
mm/selftests: Fix incorrect pointer being passed to mark_range()
selftests/mm: Add support to test 4PB VA on PPC64
selftest/mm: Fix ksm_funtional_test failures
mm/selftests: Fix split_huge_page_test failure on systems with 64KB
page size
tools/testing/selftests/mm/hugepage-mremap.c | 16 +++++++++--
.../selftests/mm/ksm_functional_tests.c | 28 +++++++++++++------
.../selftests/mm/split_huge_page_test.c | 23 +++++++++------
tools/testing/selftests/mm/thuge-gen.c | 11 +++++---
.../selftests/mm/virtual_address_range.c | 13 ++++++++-
5 files changed, 67 insertions(+), 24 deletions(-)
--
2.47.1
Hello!
KUnit offers a parameterized testing framework, where tests can be
run multiple times with different inputs.
Currently, the same `struct kunit` is used for each parameter
execution. After each run, the test instance gets cleaned up.
This creates the following limitations:
a. There is no way to store resources that are accessible across
the individual parameter test executions.
b. It's not possible to pass additional context besides the
previous parameter to `generate_params()` to get the next
parameter.
c. Test users are restricted to using pre-defined static arrays
of parameter objects or `generate_params()` to define their
parameters. There is no flexibility to pass a custom dynamic
array without using `generate_params()`, which can be complex
if generating the next parameter depends on more than just
the single previous parameter (e.g., two or more previous
parameters).
This patch series resolves these limitations by:
1. [P 1] Giving each parameterized test execution its own
`struct kunit`. This aligns more with the definition of a
`struct kunit` as a running instance of a test. It will also
remove the need to manage state, such as resetting the
`test->priv` field or the `test->status_comment` after every
parameter run.
2. [P 1] Introducing a parent pointer of type `struct kunit`.
Behind the scenes, a parent instance for the parameterized
tests will be created. It won't be used to execute any test
logic, but will instead be used as a context for shared
resources. Each individual running instance of a test will
now have a reference to that parent instance and thus, have
access to those resources.
3. [P 2] Introducing `param_init()` and `param_exit()` functions
that can set up and clean up the parent instance of the
parameterized tests. They will run once before and after the
parameterized series and provide a way for the user to
access the parent instance to add the parameter array or any
other resources to it, including custom ones to the
`test->parent->priv` field or to `test->parent->resources`
via the Resource API (link below).
https://elixir.bootlin.com/linux/v6.16-rc7/source/include/kunit/resource.h
4. [P 3, 4 & 5] Passing the parent `struct kunit` as an additional
parameter to `generate_params()`. This provides
`generate_params()` with more available context, making
parameter generation much more flexible. The
`generate_params()` implementations in the KCSAN and drm/xe
tests have been adapted to match the new function pointer
signature.
5. [P 6] Introducing a `params_data` field in `struct kunit`.
This will allow the parent instance of a test to have direct
storage of the parameter array, enabling features like using
dynamic parameter arrays or using context beyond just the
previous parameter.
Thank you!
-Marie
Marie Zhussupova (9):
kunit: Add parent kunit for parameterized test context
kunit: Introduce param_init/exit for parameterized test shared context
management
kunit: Pass additional context to generate_params for parameterized
testing
kcsan: test: Update parameter generator to new signature
drm/xe: Update parameter generator to new signature
kunit: Enable direct registration of parameter arrays to a KUnit test
kunit: Add example parameterized test with shared resources and direct
static parameter array setup
kunit: Add example parameterized test with direct dynamic parameter
array setup
Documentation: kunit: Document new parameterized test features
Documentation/dev-tools/kunit/usage.rst | 455 +++++++++++++++++++++++-
drivers/gpu/drm/xe/tests/xe_pci.c | 2 +-
include/kunit/test.h | 98 ++++-
kernel/kcsan/kcsan_test.c | 2 +-
lib/kunit/kunit-example-test.c | 207 +++++++++++
lib/kunit/test.c | 82 ++++-
6 files changed, 818 insertions(+), 28 deletions(-)
--
2.50.1.552.g942d659e1b-goog