Documentation/admin-guide/kernel-parameters.txt
Source file repositories/reference/linux-study-clean/Documentation/admin-guide/kernel-parameters.txt
File Facts
- System
- Linux kernel
- Corpus path
Documentation/admin-guide/kernel-parameters.txt- Extension
.txt- Size
- 317957 bytes
- Lines
- 8675
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
For example, to add a kprobe event on vfs_read with
arg1 and arg2, add to the command line;
kprobe_event=p,vfs_read,$arg1,$arg2
See also Documentation/trace/kprobetrace.rst "Kernel
Boot Parameter" section.
kpti= [ARM64,EARLY] Control page table isolation of
user and kernel address spaces.
Default: enabled on cores which need mitigation.
0: force disabled
1: force enabled
kunit.enable= [KUNIT] Enable executing KUnit tests. Requires
CONFIG_KUNIT to be set to be fully enabled. The
default value can be overridden via
KUNIT_DEFAULT_ENABLED.
Default is 1 (enabled)
kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
Default is 0 (don't ignore, but inject #GP)
kvm.eager_page_split=
[KVM,X86] Controls whether or not KVM will try to
proactively split all huge pages during dirty logging.
Eager page splitting reduces interruptions to vCPU
execution by eliminating the write-protection faults
and MMU lock contention that would otherwise be
required to split huge pages lazily.
VM workloads that rarely perform writes or that write
only to a small region of VM memory may benefit from
disabling eager page splitting to allow huge pages to
still be used for reads.
The behavior of eager page splitting depends on whether
KVM_DIRTY_LOG_INITIALLY_SET is enabled or disabled. If
disabled, all huge pages in a memslot will be eagerly
split when dirty logging is enabled on that memslot. If
enabled, eager page splitting will be performed during
the KVM_CLEAR_DIRTY ioctl, and only for the pages being
cleared.
Eager page splitting is only supported when kvm.tdp_mmu=Y.
Default is Y (on).
kvm.enable_pmu=[KVM,X86]
If enabled, KVM will virtualize PMU functionality based
on the virtual CPU model defined by userspace. This
can be overridden on a per-VM basis via
KVM_CAP_PMU_CAPABILITY.
If disabled, KVM will not virtualize PMU functionality,
e.g. MSRs, PMCs, PMIs, etc., even if userspace defines
a virtual CPU model that contains PMU assets.
Note, KVM's vPMU support implicitly requires running
with an in-kernel local APIC, e.g. to deliver PMIs to
the guest. Running without an in-kernel local APIC is
not supported, though KVM will allow such a combination
(with severely degraded functionality).
See also enable_mediated_pmu.
Default is Y (on).
kvm.enable_virt_at_load=[KVM,ARM64,LOONGARCH,MIPS,RISCV,X86]
If enabled, KVM will enable virtualization in hardware
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
- This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.