Re: [PATCH v3 1/3] x86/viridian: Workaround Hyper-V GP fault writing to MSR

[Jan Beulich <jbeulich@xxxxxxxx>]

On 11.09.2026 11:12, Ross Lagerwall wrote:
> The Viridian spec requires the vector to be >= 0x10 when writing to the
> SINTx MSR, otherwise it should #GP fault.
> The spec-defined initial value is 0x10000, i.e. the vector is 0. On
> startup, for some reason Windows 11 Hyper-V tries to set the MSR to
> the spec-defined initial value and since the vector is 0, it GP faults.
> Fix this by doing as Hyper-V does and only fault if the SINT is
> unmasked.
> 
> Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>