hw/pci-host/i440fx: Add PCI_HOST_{ABOVE, BELOW}_4G_MEM_SIZE properties

Introduce the properties in anticipation of QOM'ification; Q35 has the same
properties.

Note that we want to avoid a "ram size" property in the QOM interface since it
seems redundant to both properties introduced in this change. Thus the removal
of the ram_size parameter. We assume the invariant of both properties to sum up
to "ram size" which is already asserted in pc_memory_init(). Under Xen the
invariant seems to hold as well, so we now also check it there.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-Id: <20230630073720.21297-15-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/i386/pc_piix.c

@@ -224,6 +224,9 @@ static void pc_init1(MachineState *machine,
     if (!xen_enabled()) {
         pc_memory_init(pcms, system_memory, rom_memory, hole64_size);
     } else {
+        assert(machine->ram_size == x86ms->below_4g_mem_size +
+                                    x86ms->above_4g_mem_size);
+
         pc_system_flash_cleanup_unused(pcms);
         if (machine->kernel_filename != NULL) {
             /* For xen HVM direct kernel boot, load linux here */
@@ -239,7 +242,7 @@ static void pc_init1(MachineState *machine,
 
         pci_bus = i440fx_init(pci_type,
                               i440fx_host,
-                              system_memory, system_io, machine->ram_size,
+                              system_memory, system_io,
                               x86ms->below_4g_mem_size,
                               x86ms->above_4g_mem_size,
                               pci_memory, ram_memory);

hw/pci-host/i440fx.c

@@ -52,6 +52,8 @@ struct I440FXState {
     MemoryRegion *pci_address_space;
     MemoryRegion *ram_memory;
     Range pci_hole;
+    uint64_t below_4g_mem_size;
+    uint64_t above_4g_mem_size;
     uint64_t pci_hole64_size;
     bool pci_hole64_fix;
     uint32_t short_root_bus;
@@ -264,7 +266,6 @@ PCIBus *i440fx_init(const char *pci_type,
                     DeviceState *dev,
                     MemoryRegion *address_space_mem,
                     MemoryRegion *address_space_io,
-                    ram_addr_t ram_size,
                     ram_addr_t below_4g_mem_size,
                     ram_addr_t above_4g_mem_size,
                     MemoryRegion *pci_address_space,
@@ -281,6 +282,8 @@ PCIBus *i440fx_init(const char *pci_type,
     s->io_memory = address_space_io;
     s->pci_address_space = pci_address_space;
     s->ram_memory = ram_memory;
+    s->below_4g_mem_size = below_4g_mem_size;
+    s->above_4g_mem_size = above_4g_mem_size;
 
     b = pci_root_bus_new(dev, NULL, s->pci_address_space,
                          s->io_memory, 0, TYPE_PCI_BUS);
@@ -290,7 +293,7 @@ PCIBus *i440fx_init(const char *pci_type,
     d = pci_create_simple(b, 0, pci_type);
     f = I440FX_PCI_DEVICE(d);
 
-    range_set_bounds(&s->pci_hole, below_4g_mem_size,
+    range_set_bounds(&s->pci_hole, s->below_4g_mem_size,
                      IO_APIC_DEFAULT_ADDRESS - 1);
 
     /* setup pci memory mapping */
@@ -321,6 +324,7 @@ PCIBus *i440fx_init(const char *pci_type,
                  PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
     }
 
+    ram_addr_t ram_size = s->below_4g_mem_size + s->above_4g_mem_size;
     ram_size = ram_size / 8 / 1024 / 1024;
     if (ram_size > 255) {
         ram_size = 255;
@@ -380,6 +384,10 @@ static Property i440fx_props[] = {
     DEFINE_PROP_SIZE(PCI_HOST_PROP_PCI_HOLE64_SIZE, I440FXState,
                      pci_hole64_size, I440FX_PCI_HOST_HOLE64_SIZE_DEFAULT),
     DEFINE_PROP_UINT32("short_root_bus", I440FXState, short_root_bus, 0),
+    DEFINE_PROP_SIZE(PCI_HOST_BELOW_4G_MEM_SIZE, I440FXState,
+                     below_4g_mem_size, 0),
+    DEFINE_PROP_SIZE(PCI_HOST_ABOVE_4G_MEM_SIZE, I440FXState,
+                     above_4g_mem_size, 0),
     DEFINE_PROP_BOOL("x-pci-hole64-fix", I440FXState, pci_hole64_fix, true),
     DEFINE_PROP_END_OF_LIST(),
 };

include/hw/pci-host/i440fx.h

@@ -36,7 +36,6 @@ PCIBus *i440fx_init(const char *pci_type,
                     DeviceState *dev,
                     MemoryRegion *address_space_mem,
                     MemoryRegion *address_space_io,
-                    ram_addr_t ram_size,
                     ram_addr_t below_4g_mem_size,
                     ram_addr_t above_4g_mem_size,
                     MemoryRegion *pci_memory,