intel_iommu: redo configuraton check in realize

* there no point in configuring the device if realization is going to
  fail, so move the check to the beginning,
* create a separate function for the check,
* use error_setg() instead error_report().

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 18 insertions, 8 deletions

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index d22a51c488..29cd2ae51d 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -21,6 +21,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
+#include "qapi/error.h"
 #include "hw/sysbus.h"
 #include "exec/address-spaces.h"
 #include "intel_iommu_internal.h"
@@ -2460,6 +2461,18 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
     return &vtd_as->as;
 }
 
+static bool vtd_check_config(X86IOMMUState *x86_iommu, Error **errp)
+{
+    /* Currently Intel IOMMU IR only support "kernel-irqchip={off|split}" */
+    if (x86_iommu->intr_supported && kvm_irqchip_in_kernel() &&
+        !kvm_irqchip_is_split()) {
+        error_setg(errp, "Intel Interrupt Remapping cannot work with "
+                         "kernel-irqchip=on, please use 'split|off'.");
+        return false;
+    }
+    return true;
+}
+
 static void vtd_realize(DeviceState *dev, Error **errp)
 {
     PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
@@ -2469,6 +2482,11 @@ static void vtd_realize(DeviceState *dev, Error **errp)
 
     VTD_DPRINTF(GENERAL, "");
     x86_iommu->type = TYPE_INTEL;
+
+    if (!vtd_check_config(x86_iommu, errp)) {
+        return;
+    }
+
     memset(s->vtd_as_by_bus_num, 0, sizeof(s->vtd_as_by_bus_num));
     memory_region_init_io(&s->csrmem, OBJECT(s), &vtd_mem_ops, s,
                           "intel_iommu", DMAR_REG_SIZE);
@@ -2483,14 +2501,6 @@ static void vtd_realize(DeviceState *dev, Error **errp)
     pci_setup_iommu(bus, vtd_host_dma_iommu, dev);
     /* Pseudo address space under root PCI bus. */
     pcms->ioapic_as = vtd_host_dma_iommu(bus, s, Q35_PSEUDO_DEVFN_IOAPIC);
-
-    /* Currently Intel IOMMU IR only support "kernel-irqchip={off|split}" */
-    if (x86_iommu->intr_supported && kvm_irqchip_in_kernel() &&
-        !kvm_irqchip_is_split()) {
-        error_report("Intel Interrupt Remapping cannot work with "
-                     "kernel-irqchip=on, please use 'split|off'.");
-        exit(1);
-    }
 }
 
 static void vtd_class_init(ObjectClass *klass, void *data)