[Qemu-devel] [PATCH 2/3] pc: add pci64 memory hole

[Gerd Hoffmann <kraxel@redhat.com>]

This patch adds a address space hole for 64bit PCI ressources.
It starts at 0x8000000000 (512 GB) and ends at 0x10000000000 (1 TB),
thus has 512 GB in size.  This matches what the experimental seabios
patches[1] are using.

[1] http://www.kraxel.org/cgit/seabios/commit/?h=pci64

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/pc.c      |   17 ++++++++++++++---
 hw/pc.h      |    6 ++++++
 hw/pc_piix.c |   22 ++++++++++------------
 3 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index 59a7f39..b283a80 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -972,12 +972,13 @@ void pc_memory_init(MemoryRegion *system_memory,
                     const char *initrd_filename,
                     ram_addr_t below_4g_mem_size,
                     ram_addr_t above_4g_mem_size,
+                    ram_addr_t above_1t_mem_size,
                     MemoryRegion *rom_memory,
                     MemoryRegion **ram_memory)
 {
     int linux_boot, i;
     MemoryRegion *ram, *option_rom_mr;
-    MemoryRegion *ram_below_4g, *ram_above_4g;
+    MemoryRegion *ram_below_4g, *ram_above_4g, *ram_above_1t;
     void *fw_cfg;
 
     linux_boot = (kernel_filename != NULL);
@@ -988,7 +989,9 @@ void pc_memory_init(MemoryRegion *system_memory,
      */
     ram = g_malloc(sizeof(*ram));
     memory_region_init_ram(ram, "pc.ram",
-                           below_4g_mem_size + above_4g_mem_size);
+                           below_4g_mem_size +
+                           above_4g_mem_size +
+                           above_1t_mem_size);
     vmstate_register_ram_global(ram);
     *ram_memory = ram;
     ram_below_4g = g_malloc(sizeof(*ram_below_4g));
@@ -999,9 +1002,17 @@ void pc_memory_init(MemoryRegion *system_memory,
         ram_above_4g = g_malloc(sizeof(*ram_above_4g));
         memory_region_init_alias(ram_above_4g, "ram-above-4g", ram,
                                  below_4g_mem_size, above_4g_mem_size);
-        memory_region_add_subregion(system_memory, 0x100000000ULL,
+        memory_region_add_subregion(system_memory, PCI_HOLE_END,
                                     ram_above_4g);
     }
+    if (above_1t_mem_size > 0) {
+        ram_above_1t = g_malloc(sizeof(*ram_above_1t));
+        memory_region_init_alias(ram_above_1t, "ram-above-1t", ram,
+                                 below_4g_mem_size + above_4g_mem_size,
+                                 above_1t_mem_size);
+        memory_region_add_subregion(system_memory, PCI_HOLE64_END,
+                                    ram_above_1t);
+    }
 
 
     /* Initialize PC system firmware */
diff --git a/hw/pc.h b/hw/pc.h
index 74d3369..0c5e14e 100644
--- a/hw/pc.h
+++ b/hw/pc.h
@@ -12,6 +12,11 @@
 
 /* PC-style peripherals (also used by other machines).  */
 
+#define PCI_HOLE_START   0x0000e0000000ULL
+#define PCI_HOLE_END     0x000100000000ULL
+#define PCI_HOLE64_START 0x008000000000ULL
+#define PCI_HOLE64_END   0x010000000000ULL
+
 /* serial.c */
 
 SerialState *serial_init(int base, qemu_irq irq, int baudbase,
@@ -112,6 +117,7 @@ void pc_memory_init(MemoryRegion *system_memory,
                     const char *initrd_filename,
                     ram_addr_t below_4g_mem_size,
                     ram_addr_t above_4g_mem_size,
+                    ram_addr_t above_1t_mem_size,
                     MemoryRegion *rom_memory,
                     MemoryRegion **ram_memory);
 qemu_irq *pc_allocate_cpu_irq(void);
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 5e11d15..3c40d90 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -131,7 +131,7 @@ static void pc_init1(MemoryRegion *system_memory,
                      int kvmclock_enabled)
 {
     int i;
-    ram_addr_t below_4g_mem_size, above_4g_mem_size;
+    ram_addr_t below_4g_mem_size, above_4g_mem_size, above_1t_mem_size;
     PCIBus *pci_bus;
     ISABus *isa_bus;
     PCII440FXState *i440fx_state;
@@ -156,13 +156,10 @@ static void pc_init1(MemoryRegion *system_memory,
         kvmclock_create();
     }
 
-    if (ram_size >= 0xe0000000 ) {
-        above_4g_mem_size = ram_size - 0xe0000000;
-        below_4g_mem_size = 0xe0000000;
-    } else {
-        above_4g_mem_size = 0;
-        below_4g_mem_size = ram_size;
-    }
+    below_4g_mem_size = MIN(ram_size, PCI_HOLE_START);
+    above_4g_mem_size = MIN(ram_size - below_4g_mem_size,
+                            PCI_HOLE64_START - PCI_HOLE_END);
+    above_1t_mem_size = ram_size - below_4g_mem_size - above_4g_mem_size;
 
     if (pci_enabled) {
         pci_memory = g_new(MemoryRegion, 1);
@@ -177,7 +174,7 @@ static void pc_init1(MemoryRegion *system_memory,
     if (!xen_enabled()) {
         pc_memory_init(system_memory,
                        kernel_filename, kernel_cmdline, initrd_filename,
-                       below_4g_mem_size, above_4g_mem_size,
+                       below_4g_mem_size, above_4g_mem_size, above_1t_mem_size,
                        pci_enabled ? rom_memory : system_memory, &ram_memory);
     }
 
@@ -194,11 +191,12 @@ static void pc_init1(MemoryRegion *system_memory,
         pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, &isa_bus, gsi,
                               system_memory, system_io, ram_size,
                               below_4g_mem_size,
-                              0x100000000ULL - below_4g_mem_size,
-                              0x100000000ULL + above_4g_mem_size,
+                              PCI_HOLE_END - below_4g_mem_size,
+                              PCI_HOLE_END + above_4g_mem_size,
                               (sizeof(target_phys_addr_t) == 4
                                ? 0
-                               : ((uint64_t)1 << 62)),
+                               : (PCI_HOLE64_END - PCI_HOLE_END -
+                                  above_4g_mem_size)),
                               pci_memory, ram_memory);
     } else {
         pci_bus = NULL;
-- 
1.7.1