intel_iommu: Fix irqchip / X2APIC configuration checks

We don't need to check kvm_enable_x2apic(). It's perfectly OK to support
interrupt remapping even if we can't address CPUs above 254. Kind of
pointless, but still functional.

The check on kvm_enable_x2apic() needs to happen *anyway* in order to
allow CPUs above 254 even without an IOMMU, so allow that to happen
elsewhere.

However, we do require the *split* irqchip in order to rewrite I/OAPIC
destinations. So fix that check while we're here.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20220314142544.150555-4-dwmw2@infradead.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index d3361c8313a77da270c411aa017fd0d3852c40e1..d310532108cdf99aaf68a018facfdcd8ea9f7e6b 100644 (file)
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3786,15 +3786,10 @@ 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_in_kernel()) {
+        if (!kvm_irqchip_is_split()) {
             error_setg(errp, "eim=on requires accel=kvm,kernel-irqchip=split");
             return false;
         }
-        if (!kvm_enable_x2apic()) {
-            error_setg(errp, "eim=on requires support on the KVM side"
-                             "(X2APIC_API, first shipped in v4.7)");
-            return false;
-        }
     }
 
     /* Currently only address widths supported are 39 and 48 bits */