[PATCH 00/11] support SCTLR2_ELx
Yeoreum Yun
yeoreum.yun at arm.com
Mon Aug 4 05:17:13 PDT 2025
This series introduces initial support for the SCTLR2_ELx registers in Linux.
The feature is optional starting from ARMv8.8/ARMv9.3,
and becomes mandatory from ARMv8.9/ARMv9.4.
Currently, Linux has no strict need to modify SCTLR2_ELx—
at least assuming that firmware initializes
these registers to reasonable defaults.
However, several upcoming architectural features will require configuring
control bits in these registers.
Notable examples include FEAT_PAuth_LR and FEAT_CPA2.
This series is based on v6.16 and probably KVM-safe but
Not tested yet:
- nVHE boot.
Yeoreum Yun (11):
arm64/sysreg: add system registers SCTLR2_EL2
arm64: make SCTLR2_EL1 accessible
arm64: initialise SCTLR2_ELx register at boot time
arm64: cpufeature: add FEAT_SCTLR2 feature
arm64: save/restore SCTLR2_EL1 when cpu_suspend()/resume()
arm64: init SCTLR2_EL1 at cpu_soft_restart()
arm64: make the per-task SCTLR2_EL1
KVM: arm64: initialise SCTLR2_EL1 at __kvm_host_psci_cpu_entry()
KVM: arm64: support SCTLR2_EL1 for guest
KVM: arm64: nv: support SCTLR2_ELx on nv
KVM: arm64: expose FEAT_SCTLR2 feature to guest
arch/arm64/include/asm/el2_setup.h | 14 +++++++++++-
arch/arm64/include/asm/kvm_host.h | 7 ++++++
arch/arm64/include/asm/processor.h | 5 +++++
arch/arm64/include/asm/suspend.h | 2 +-
arch/arm64/include/asm/sysreg.h | 22 ++++++++++++++++++
arch/arm64/include/asm/vncr_mapping.h | 1 +
arch/arm64/kernel/cpu-reset.S | 6 +++++
arch/arm64/kernel/cpufeature.c | 8 +++++++
arch/arm64/kernel/head.S | 5 ++++-
arch/arm64/kernel/process.c | 9 ++++++++
arch/arm64/kvm/emulate-nested.c | 2 ++
arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 16 +++++++++++++
arch/arm64/kvm/hyp/nvhe/psci-relay.c | 3 +++
arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 6 +++++
arch/arm64/kvm/nested.c | 13 +++++++++++
arch/arm64/kvm/sys_regs.c | 25 +++++++++++++++++++--
arch/arm64/mm/proc.S | 26 +++++++++++++++-------
arch/arm64/tools/cpucaps | 1 +
arch/arm64/tools/sysreg | 17 ++++++++++++++
19 files changed, 175 insertions(+), 13 deletions(-)
base-commit: 038d61fd642278bab63ee8ef722c50d10ab01e8f
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
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