Re: [PATCH 3/5] KVM: x86/xen: Consult kvm_xen_enabled when checking for Xen MSR writes

[David Woodhouse]

On Fri, 2025-01-31 at 17:13 -0800, Sean Christopherson wrote:
> Query kvm_xen_enabled when detecting writes to the Xen hypercall page MSR
> so that the check is optimized away in the likely scenario that Xen isn't
> enabled for the VM.
> 
> Deliberately open code the check instead of using kvm_xen_msr_enabled() in
> order to avoid a double load of xen_hvm_config.msr (which is admittedly
> rather pointless given the widespread lack of READ_ONCE() usage on the
> plethora of vCPU-scoped accesses to kvm->arch.xen state).
> 
> No functional change intended.
> 
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>

Reviewed-by: David Woodhouse <dwmw@xxxxxxxxxxxx>

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