Re: [PATCH v1 2/2] x86/viridian: Implement synthetic timer direct mode

On 8/28/26 3:11 PM, Tu Dinh wrote:
> On 28/08/2026 15:14, Ross Lagerwall wrote:
>> In direct mode, the timer asserts an interrupt on expiration rather than
>> using a SynIC message. It is useful to implement this since Windows 11's
>> Hyper-V can only use synthetic timers in direct mode.
> 
> Hello, is this new behavior compared to Server 2025? What happens if
> direct mode is not available, does it fall back to disabling stimer?

No, it's not new behaviour. According to Linux commit 8644f771e07c it
has been this way since 2016. If direct mode is not available, the VM
still works but without using synthetic timers.

Ross