Re: [PATCH v3 2/3] x86/viridian: Implement synthetic timer direct mode

[Jan Beulich <jbeulich@xxxxxxxx>]

On 11.09.2026 11:12, 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.
> 
> To avoid changing behaviour in existing guests, add a new Viridian flag,
> stimer_direct, to control whether this feature is visible and usable.
> 
> At the same time, check that the reserved bits are zero and the APIC
> vector is only set when using direct mode since this is enforced by
> Hyper-V (although not mentioned in the spec).
> 
> Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>