[PULL 52/91] intel_iommu: Fix irqchip / X2APIC configuration checks

Michael S. Tsirkin posted 91 patches 3 years, 7 months ago
Maintainers: "Marc-André Lureau" <marcandre.lureau@redhat.com>, Gerd Hoffmann <kraxel@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Greg Kurz <groug@kaod.org>, Christian Schoenebeck <qemu_oss@crudebyte.com>, Igor Mammedov <imammedo@redhat.com>, Ani Sinha <ani@anisinha.ca>, Peter Maydell <peter.maydell@linaro.org>, Raphael Norwitz <raphael.norwitz@nutanix.com>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Laurent Vivier <lvivier@redhat.com>, Amit Shah <amit@kernel.org>, Paolo Bonzini <pbonzini@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <f4bug@amsat.org>, Yanan Wang <wangyanan55@huawei.com>, Ben Widawsky <ben.widawsky@intel.com>, Jonathan Cameron <jonathan.cameron@huawei.com>, Richard Henderson <richard.henderson@linaro.org>, Peter Xu <peterx@redhat.com>, Jason Wang <jasowang@redhat.com>, Sergio Lopez <slp@redhat.com>, Fam Zheng <fam@euphon.net>, Mathieu Poirier <mathieu.poirier@linaro.org>, David Hildenbrand <david@redhat.com>, "Gonglei (Arei)" <arei.gonglei@huawei.com>, Eric Auger <eric.auger@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Michael Roth <michael.roth@amd.com>, Marcelo Tosatti <mtosatti@redhat.com>, Thomas Huth <thuth@redhat.com>
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[PULL 52/91] intel_iommu: Fix irqchip / X2APIC configuration checks
Posted by Michael S. Tsirkin 3 years, 7 months ago
From: David Woodhouse <dwmw2@infradead.org>

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>
---
 hw/i386/intel_iommu.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index d3361c8313..d310532108 100644
--- 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 */
-- 
MST