The default high mmio size of GPEX PCIE host controller is 64G bytes
on virt machine. It may meet requirements with some cards, here adds
property highmem-mmio-size to set high mmio size.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 hw/loongarch/virt.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index 73c0494422..dc7de2f927 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -7,6 +7,7 @@
 #include "qemu/osdep.h"
 #include "qemu/units.h"
 #include "qemu/datadir.h"
+#include "qemu/cutils.h"
 #include "qapi/error.h"
 #include "exec/target_page.h"
 #include "hw/boards.h"
@@ -82,6 +83,43 @@ static void virt_set_highmem_mmio(Object *obj, bool value, Error **errp)
     lvms->highmem_mmio = value;
 }
 
+static void virt_get_highmem_mmio_size(Object *obj, Visitor *v,
+                                       const char *name, void *opaque,
+                                       Error **errp)
+{
+    LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(obj);
+    uint64_t size = lvms->gpex.mmio64.size;
+
+    visit_type_size(v, name, &size, errp);
+}
+
+static void virt_set_highmem_mmio_size(Object *obj, Visitor *v,
+                                       const char *name, void *opaque,
+                                       Error **errp)
+{
+    LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(obj);
+    uint64_t size;
+
+    if (!visit_type_size(v, name, &size, errp)) {
+        return;
+    }
+
+    if (!is_power_of_2(size)) {
+        error_setg(errp, "highmem-mmio-size is not a power of 2");
+        return;
+    }
+
+    if (size < DEFAULT_HIGH_PCIE_MMIO_SIZE) {
+        char *sz = size_to_str(DEFAULT_HIGH_PCIE_MMIO_SIZE);
+        error_setg(errp, "highmem-mmio-size cannot be set to a lower value "
+                         "than the default (%s)", sz);
+        g_free(sz);
+        return;
+    }
+
+    lvms->gpex.mmio64.size = size;
+}
+
 static PFlashCFI01 *virt_flash_create1(LoongArchVirtMachineState *lvms,
                                        const char *name,
                                        const char *alias_prop_name)
@@ -1341,6 +1379,13 @@ static void virt_class_init(ObjectClass *oc, const void *data)
     object_class_property_set_description(oc, "highmem-mmio",
                                           "Set on/off to enable/disable high "
                                           "memory region for PCI MMIO");
+    object_class_property_add(oc, "highmem-mmio-size", "size",
+                                   virt_get_highmem_mmio_size,
+                                   virt_set_highmem_mmio_size,
+                                   NULL, NULL);
+    object_class_property_set_description(oc, "highmem-mmio-size",
+                                          "Set the high memory region size "
+                                          "for PCI MMIO");
 }
 
 static const TypeInfo virt_machine_types[] = {
-- 
2.39.3