intel_iommu: allow Extended Interrupt Mode when using userspace APIC

As userspace APIC now supports x2APIC, intel interrupt remapping
hardware can be set to EIM mode when userspace local APIC is used.

Suggested-by: Joao Martins <joao.m.martins@oracle.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Message-Id: <20240111154404.5333-5-minhquangbui99@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/i386/intel_iommu.c

@@ -4124,11 +4124,7 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
                                               ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
     }
     if (s->intr_eim == ON_OFF_AUTO_ON && !s->buggy_eim) {
-        if (!kvm_irqchip_is_split()) {
-            error_setg(errp, "eim=on requires accel=kvm,kernel-irqchip=split");
-            return false;
-        }
-        if (kvm_enabled() && !kvm_enable_x2apic()) {
+        if (kvm_irqchip_is_split() && !kvm_enable_x2apic()) {
             error_setg(errp, "eim=on requires support on the KVM side"
                              "(X2APIC_API, first shipped in v4.7)");
             return false;