Re: [RFC PATCH v3 23/59] KVM: x86: Allow host-initiated WRMSR to set X2APIC regardless of CPUID

[Thomas Gleixner]

On Wed, Nov 24 2021 at 16:20, isaku yamahata wrote:
> Let userspace, or in the case of TDX, KVM itself, enable X2APIC even if
> X2APIC is not reported as supported in the guest's CPU model.  KVM
> generally does not force specific ordering between ioctls(), e.g. this
> forces userspace to configure CPUID before MSRs.  And for TDX, vCPUs
> will always run with X2APIC enabled, e.g. KVM will want/need to enable
> X2APIC from time zero.

This is complete crap. Fix the broken user space and do not add
horrible hacks to the kernel.

Thanks,

        tglx