In order to have more PCI host bridges to re-use the
generic pci_host_data_le_ops MemoryRegionOps, add the
'config-reg-check-high-bit' property (%true by default).

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/pci/pci_host.h |  1 +
 hw/pci/pci_host.c         | 10 +++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/include/hw/pci/pci_host.h b/include/hw/pci/pci_host.h
index 954dd446fa4..c04a567ec57 100644
--- a/include/hw/pci/pci_host.h
+++ b/include/hw/pci/pci_host.h
@@ -43,6 +43,7 @@ struct PCIHostState {
     MemoryRegion data_mem;
     MemoryRegion mmcfg;
     uint32_t config_reg;
+    bool config_reg_check_high_bit;
     bool mig_enabled;
     PCIBus *bus;
     bool bypass_iommu;
diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
index b5c624e12e8..06003188e1d 100644
--- a/hw/pci/pci_host.c
+++ b/hw/pci/pci_host.c
@@ -184,8 +184,10 @@ static void pci_host_data_write(void *opaque, hwaddr addr,
 {
     PCIHostState *s = opaque;
 
-    if (s->config_reg & (1u << 31))
-        pci_data_write(s->bus, s->config_reg | (addr & 3), val, len);
+    if (s->config_reg_check_high_bit && !(s->config_reg & (1U << 31))) {
+        return;
+    }
+    pci_data_write(s->bus, s->config_reg | (addr & 3), val, len);
 }
 
 static uint64_t pci_host_data_read(void *opaque,
@@ -193,7 +195,7 @@ static uint64_t pci_host_data_read(void *opaque,
 {
     PCIHostState *s = opaque;
 
-    if (!(s->config_reg & (1U << 31))) {
+    if (s->config_reg_check_high_bit && !(s->config_reg & (1U << 31))) {
         return 0xffffffff;
     }
     return pci_data_read(s->bus, s->config_reg | (addr & 3), len);
@@ -237,6 +239,8 @@ const VMStateDescription vmstate_pcihost = {
 static const Property pci_host_properties_common[] = {
     DEFINE_PROP_BOOL("x-config-reg-migration-enabled", PCIHostState,
                      mig_enabled, true),
+    DEFINE_PROP_BOOL("config-reg-check-high-bit", PCIHostState,
+                     config_reg_check_high_bit, true),
     DEFINE_PROP_BOOL(PCI_HOST_BYPASS_IOMMU, PCIHostState, bypass_iommu, false),
 };
 
-- 
2.51.0