[Qemu-devel] [PATCH V6 06/11] pci.c: Add pci_check_bar_overlap

[Anthony PERARD]

From: Yuji Shimada <address@hidden>

This function helps Xen PCI Passthrough device to check for overlap.

Signed-off-by: Yuji Shimada <address@hidden>
Signed-off-by: Anthony PERARD <address@hidden>
---
 hw/pci.c |   47 +++++++++++++++++++++++++++++++++++++++++++++++
 hw/pci.h |    3 +++
 2 files changed, 50 insertions(+), 0 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index 5f4f80e..ebb5de9 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -1985,6 +1985,53 @@ MemoryRegion *pci_address_space_io(PCIDevice *dev)
     return dev->bus->address_space_io;
 }
 
+int pci_check_bar_overlap(PCIDevice *dev,
+                          pcibus_t addr, pcibus_t size, uint8_t type)
+{
+    PCIBus *bus = dev->bus;
+    PCIDevice *devices = NULL;
+    PCIIORegion *r;
+    int i, j;
+    int rc = 0;
+
+    /* check Overlapped to Base Address */
+    for (i = 0; i < ARRAY_SIZE(bus->devices); i++) {
+        devices = bus->devices[i];
+        if (!devices) {
+            continue;
+        }
+
+        /* skip itself */
+        if (devices->devfn == dev->devfn) {
+            continue;
+        }
+
+        for (j = 0; j < PCI_NUM_REGIONS; j++) {
+            r = &devices->io_regions[j];
+
+            /* skip different resource type, but don't skip when
+             * prefetch and non-prefetch memory are compared.
+             */
+            if (type != r->type) {
+                if (type & PCI_BASE_ADDRESS_SPACE_IO ||
+                    r->type & PCI_BASE_ADDRESS_SPACE_IO) {
+                    continue;
+                }
+            }
+
+            if ((addr < (r->addr + r->size)) && ((addr + size) > r->addr)) {
+                printf("Overlapped to device[%02x:%02x.%x][Region:%d]"
+                       "[Address:%"PRIx64"h][Size:%"PRIx64"h]\n",
+                       pci_bus_num(bus), PCI_SLOT(devices->devfn),
+                       PCI_FUNC(devices->devfn), j, r->addr, r->size);
+                rc = 1;
+            }
+        }
+    }
+
+    return rc;
+}
+
 static void pci_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
diff --git a/hw/pci.h b/hw/pci.h
index 33b0b18..f05fda5 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -566,4 +566,7 @@ extern const VMStateDescription vmstate_pci_device;
     .offset     = vmstate_offset_pointer(_state, _field, PCIDevice), \
 }
 
+int pci_check_bar_overlap(PCIDevice *dev,
+                          pcibus_t addr, pcibus_t size, uint8_t type);
+
 #endif
-- 
Anthony PERARD