Since Armv9.6, FEAT_LSUI supplies the load/store instructions for
previleged level to access to access user memory without clearing
PSTATE.PAN bit.
This patchset support FEAT_LSUI and applies in futex atomic operation
and user_swpX emulation where can replace from ldxr/st{l}xr
pair implmentation with clearing PSTATE.PAN bit to correspondant
load/store unprevileged atomic operation without clearing PSTATE.PAN bit.
Patch Sequences
================
Patch #1 adds cpufeature for FEAT_LSUI
Patch #2-#3 expose FEAT_LSUI to guest
Patch #4 adds Kconfig for FEAT_LSUI
Patch #5-#6 support futex atomic-op with FEAT_LSUI
Patch #7-#9 support user_swpX emulation with FEAT_LSUI
Patch History
==============
from v10 to v11:
- use cast instruction to emulate deprecated swpb instruction
- https://lore.kernel.org/all/[email protected]/
from v9 to v10:
- apply FEAT_LSUI to user_swpX emulation.
- add test coverage for LSUI bit in ID_AA64ISAR3_EL1
- rebase to v6.18-rc4
- https://lore.kernel.org/all/[email protected]/
from v8 to v9:
- refotoring __lsui_cmpxchg64()
- rebase to v6.17-rc7
- https://lore.kernel.org/all/[email protected]/
from v7 to v8:
- implements futex_atomic_eor() and futex_atomic_cmpxchg() with casalt
with C helper.
- Drop the small optimisation on ll/sc futex_atomic_set operation.
- modify some commit message.
- https://lore.kernel.org/all/[email protected]/
from v6 to v7:
- wrap FEAT_LSUI with CONFIG_AS_HAS_LSUI in cpufeature
- remove unnecessary addition of indentation.
- remove unnecessary mte_tco_enable()/disable() on LSUI operation.
- https://lore.kernel.org/all/[email protected]/
from v5 to v6:
- rebase to v6.17-rc1
- https://lore.kernel.org/all/[email protected]/
from v4 to v5:
- remove futex_ll_sc.h futext_lsui and lsui.h and move them to futex.h
- reorganize the patches.
- https://lore.kernel.org/all/[email protected]/
from v3 to v4:
- rebase to v6.16-rc7
- modify some patch's title.
- https://lore.kernel.org/all/[email protected]/
from v2 to v3:
- expose FEAT_LUSI to guest
- add help section for LUSI Kconfig
- https://lore.kernel.org/all/[email protected]/
from v1 to v2:
- remove empty v9.6 menu entry
- locate HAS_LUSI in cpucaps in order
- https://lore.kernel.org/all/[email protected]/
Yeoreum Yun (9):
arm64: cpufeature: add FEAT_LSUI
KVM: arm64: expose FEAT_LSUI to guest
KVM: arm64: kselftest: set_id_regs: add test for FEAT_LSUI
arm64: Kconfig: Detect toolchain support for LSUI
arm64: futex: refactor futex atomic operation
arm64: futex: support futex with FEAT_LSUI
arm64: separate common LSUI definitions into lsui.h
arm64: armv8_deprecated: convert user_swpX to inline function
arm64: armv8_deprecated: apply FEAT_LSUI for swpX emulation.
arch/arm64/Kconfig | 5 +
arch/arm64/include/asm/futex.h | 291 +++++++++++++++---
arch/arm64/include/asm/lsui.h | 25 ++
arch/arm64/kernel/armv8_deprecated.c | 111 +++++--
arch/arm64/kernel/cpufeature.c | 10 +
arch/arm64/kvm/sys_regs.c | 3 +-
arch/arm64/tools/cpucaps | 1 +
.../testing/selftests/kvm/arm64/set_id_regs.c | 1 +
8 files changed, 381 insertions(+), 66 deletions(-)
create mode 100644 arch/arm64/include/asm/lsui.h
base-commit: 6146a0f1dfae5d37442a9ddcba012add260bceb0
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LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
