kvm: nVMX: Enforce cpl=0 for VMX instructions

VMX instructions executed inside a L1 VM will always trigger a VM exit
even when executed with cpl 3. This means we must perform the
privilege check in software.

Fixes: 70f3aac964ae("kvm: nVMX: Remove superfluous VMX instruction fault checks")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Wilhelm <fwilhelm@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
static void shrink_ple_window(struct kvm_vcpu *vcpu)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	int old = vmx->ple_window;

	vmx->ple_window = __shrink_ple_window(old, ple_window,
					      ple_window_shrink,
					      ple_window);

	if (vmx->ple_window != old)
		vmx->ple_window_dirty = true;

	trace_kvm_ple_window_shrink(vcpu->vcpu_id, vmx->ple_window, old);
}

static void shrink_ple_window(struct kvm_vcpu *vcpu)
{
	struct vcpu_vmx *vmx = to_vmx(vcpu);
	int old = vmx->ple_window;

	vmx->ple_window = __shrink_ple_window(old, ple_window,
					      ple_window_shrink,
					      ple_window);

	if (vmx->ple_window != old)
		vmx->ple_window_dirty = true;

	trace_kvm_ple_window_shrink(vcpu->vcpu_id, vmx->ple_window, old);
}
