Bill Nguyen 744104654d x86/vcpu: expose VMX-preemption timer scale MSR
Currently, the kernel permits userspace VMMs to enable and use the
VMX-preemption timer by allowing writes to the following VMCS fields:
- VMX_GUEST_PREEMPTION_TIMER_VALUE (count)
- VMX_CONTROL_PIN_EXECUTION_CONTROLS (timer enable bit)
- VMX_CONTROL_EXIT_CONTROLS (save current count on context switch bit)

It also forwards the timer expiry event as a VM exit.

But it does not tell userspace how fast the timer will count down,
making it impossible to use. This commit exposes the timer's scale
via `seL4_X86_VCPU_ReadMSR`.

Signed-off-by: Bill Nguyen <bill.nguyen@unsw.edu.au>
2026-05-09 10:54:59 +02:00
2026-05-06 14:19:38 +02:00
2026-03-24 15:03:39 +11:00
2026-03-12 11:28:26 +11:00
2026-05-06 14:19:38 +02:00
2020-04-01 17:23:36 +08:00
2026-03-24 15:03:39 +11:00
2026-03-12 11:28:26 +11:00
2025-05-26 06:01:48 +02:00
2022-05-18 13:40:55 +10:00
2025-02-26 17:11:57 +11:00
2026-03-31 10:58:57 +11:00

The seL4 microkernel

CII Best Practices CI seL4Test C Parser Compile Proof Sync RefMan XML

This project contains the source code of seL4 microkernel.

For details about the seL4 microkernel, including details about its formal correctness proof, please see the sel4.systems website and associated FAQ.

DOIs for citing recent releases of this repository:

  • DOI

We welcome contributions to seL4. Please see the website for information on how to contribute.

This repository is usually not used in isolation, but as part of the build system in a larger project.

seL4 Basics

Community

See also the contact links on the seL4 website.

Reporting security vulnerabilities

If you believe you have found a security vulnerability in seL4 or related software, we ask you to follow our vulnerability disclosure policy.

Manual

A hosted PDF version of the manual for the most recent release can be found here.

A web version of the API documentation is available as well.

Repository Overview

  • include and src: C and ASM source code of seL4
  • tools: build tools
  • libsel4: C bindings for the seL4 ABI
  • manual: LaTeX sources of the seL4 reference manual

Build Instructions

See the seL4 website for build instructions.

Status

License

See the file LICENSE.md.

Description
The seL4 microkernel
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