[RFC PATCH v4 18/30] Introduce paravirt interface QEMU_CFG_PCI_WINDOW

[Vasilis Liaskovitis]

Qemu calculates the 32-bit and 64-bit PCI starting offsets based on
initial memory and hotplug-able dimms. This info needs to be passed to Seabios
for PCI initialization.

Signed-off-by: Vasilis Liaskovitis 
---
 hw/fw_cfg.h  |    1 +
 hw/pc_piix.c |   10 ++++++++++
 hw/pc_q35.c  |    9 +++++++++
 3 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/hw/fw_cfg.h b/hw/fw_cfg.h
index 619a394..8b48493 100644
--- a/hw/fw_cfg.h
+++ b/hw/fw_cfg.h
@@ -27,6 +27,7 @@
 #define FW_CFG_SETUP_SIZE       0x17
 #define FW_CFG_SETUP_DATA       0x18
 #define FW_CFG_FILE_DIR         0x19
+#define FW_CFG_PCI_WINDOW       0x1a

#define FW_CFG_FILE_FIRST       0x20
 #define FW_CFG_FILE_SLOTS       0x10
diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 1a99852..b6633e8 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -48,6 +48,7 @@
 #  include <xen/hvm/hvm_info_table.h>
 #endif
 #include "piix_pci.h"
+#include "fw_cfg.h"

#define MAX_IDE_BUS 2

@@ -86,6 +87,7 @@ static void pc_init1(MemoryRegion *system_memory,
     MemoryRegion *pci_memory;
     MemoryRegion *rom_memory;
     void *fw_cfg = NULL;
+    uint64_t *pci_window_fw_cfg;
     I440FXState *i440fx_host;
     PIIX3State *piix3;

@@ -141,6 +143,14 @@ static void pc_init1(MemoryRegion *system_memory,

qdev_init_nofail(DEVICE(i440fx_host));
         bochs_meminfo_bios_init(fw_cfg);
+
+        pci_window_fw_cfg = g_malloc0(2 * 8);
+        pci_window_fw_cfg[0] = cpu_to_le64(i440fx_host->mch.below_4g_mem_size);
+        pci_window_fw_cfg[1] = cpu_to_le64(0x100000000ULL +
+                i440fx_host->mch.above_4g_mem_size);
+        fw_cfg_add_bytes(fw_cfg, FW_CFG_PCI_WINDOW,
+                            (uint8_t *)pci_window_fw_cfg, 2 * 8);
+
         i440fx_state = &i440fx_host->mch;
         pci_bus = i440fx_host->parent_obj.bus;
         /* Xen supports additional interrupt routes from the PCI devices to
diff --git a/hw/pc_q35.c b/hw/pc_q35.c
index 7ce0b53..e35814a 100644
--- a/hw/pc_q35.c
+++ b/hw/pc_q35.c
@@ -87,6 +87,7 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
     PCIDevice *ahci;
     qemu_irq *cmos_s3;
     void *fw_cfg = NULL;
+    uint64_t *pci_window_fw_cfg;

pc_cpus_init(cpu_model);

@@ -139,6 +140,14 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
     /* pci */
     qdev_init_nofail(DEVICE(q35_host));
     bochs_meminfo_bios_init(fw_cfg);
+
+    pci_window_fw_cfg = g_malloc0(2 * 8);
+    pci_window_fw_cfg[0] = cpu_to_le64(MCH_HOST_BRIDGE_PCIEXBAR_DEFAULT);
+    pci_window_fw_cfg[1] = cpu_to_le64(0x100000000ULL +
+            q35_host->mch.above_4g_mem_size);
+    fw_cfg_add_bytes(fw_cfg, FW_CFG_PCI_WINDOW,
+                        (uint8_t *)pci_window_fw_cfg, 2 * 8);
+
     host_bus = q35_host->host.pci.bus;
     /* create ISA bus */
     lpc = pci_create_simple_multifunction(host_bus, PCI_DEVFN(ICH9_LPC_DEV,