x86-iommu: turn on IR by default if proper

When the user didn't specify "intremap" for the IOMMU device, we turn
it on by default if it is supported.  This will turn IR on for the
default Q35 platform as long as the IOMMU device is specified on new
kernels.

Signed-off-by: Peter Xu <peterx@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/i386/x86-iommu.c b/hw/i386/x86-iommu.c
index 61ee0f1..d1534c1 100644 (file)
--- a/hw/i386/x86-iommu.c
+++ b/hw/i386/x86-iommu.c
@@ -112,6 +112,7 @@ static void x86_iommu_realize(DeviceState *dev, Error **errp)
     PCMachineState *pcms =
         PC_MACHINE(object_dynamic_cast(OBJECT(ms), TYPE_PC_MACHINE));
     QLIST_INIT(&x86_iommu->iec_notifiers);
+    bool irq_all_kernel = kvm_irqchip_in_kernel() && !kvm_irqchip_is_split();
 
     if (!pcms || !pcms->bus) {
         error_setg(errp, "Machine-type '%s' not supported by IOMMU",
@@ -121,12 +122,12 @@ static void x86_iommu_realize(DeviceState *dev, Error **errp)
 
     /* If the user didn't specify IR, choose a default value for it */
     if (x86_iommu->intr_supported == ON_OFF_AUTO_AUTO) {
-        x86_iommu->intr_supported = ON_OFF_AUTO_OFF;
+        x86_iommu->intr_supported = irq_all_kernel ?
+            ON_OFF_AUTO_OFF : ON_OFF_AUTO_ON;
     }
 
     /* Both Intel and AMD IOMMU IR only support "kernel-irqchip={off|split}" */
-    if (x86_iommu_ir_supported(x86_iommu) && kvm_irqchip_in_kernel() &&
-        !kvm_irqchip_is_split()) {
+    if (x86_iommu_ir_supported(x86_iommu) && irq_all_kernel) {
         error_setg(errp, "Interrupt Remapping cannot work with "
                          "kernel-irqchip=on, please use 'split|off'.");
         return;