From: Sairaj Kodilkar <sarunkod@amd.com>

Setting up IOAPIC memory region requires mr_sys and mr_ir. Currently
these two memory regions are setup after the initializing the IOAPIC
memory region, which cause `amdvi_host_dma_iommu()` to use unitialized
mr_sys and mr_ir.

Move the IOAPIC memory region initialization to the end in order to use
the mr_sys and mr_ir regions after they are fully initialized.

Fixes: 577c470f4326 ("x86_iommu/amd: Prepare for interrupt remap support")
Signed-off-by: Sairaj Kodilkar <sarunkod@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Message-Id: <20250801060507.3382-4-sarunkod@amd.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit a7842d94067cddc80b47ac42fb6e49e2fc02a3c5)
(Mjt: context fix due to missing v10.0.0-833-gf864a3235ea1
 "hw/i386/amd_iommu: Isolate AMDVI-PCI from amd-iommu device
 to allow full control over the PCI device creation")
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index f773653487..37447dca25 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -1620,9 +1620,6 @@ static void amdvi_sysbus_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    /* Pseudo address space under root PCI bus. */
-    x86ms->ioapic_as = amdvi_host_dma_iommu(bus, s, AMDVI_IOAPIC_SB_DEVID);
-
     /* set up MMIO */
     memory_region_init_io(&s->mr_mmio, OBJECT(s), &mmio_mem_ops, s,
                           "amdvi-mmio", AMDVI_MMIO_SIZE);
@@ -1645,6 +1642,9 @@ static void amdvi_sysbus_realize(DeviceState *dev, Error **errp)
     memory_region_add_subregion_overlap(&s->mr_sys, AMDVI_INT_ADDR_FIRST,
                                         &s->mr_ir, 1);
 
+    /* Pseudo address space under root PCI bus. */
+    x86ms->ioapic_as = amdvi_host_dma_iommu(bus, s, AMDVI_IOAPIC_SB_DEVID);
+
     if (kvm_enabled() && x86ms->apic_id_limit > 255 && !s->xtsup) {
         error_report("AMD IOMMU with x2APIC configuration requires xtsup=on");
         exit(EXIT_FAILURE);
-- 
2.47.2