[Qemu-devel] [PATCH RFC V1 06/11] pci.c: Add pci_check_bar_overlap

[Anthony PERARD <anthony.perard@citrix.com>]

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

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
---
 hw/pci.c |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 hw/pci.h |    3 +++
 2 files changed, 49 insertions(+), 0 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index af74003..56e94d1 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -2196,3 +2196,49 @@ MemoryRegion *pci_address_space(PCIDevice *dev)
 {
     return dev->bus->address_space_mem;
 }
+
+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++) {
+        if (!(devices = bus->devices[i])) {
+            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;
+}
diff --git a/hw/pci.h b/hw/pci.h
index c04b169..97996b5 100644
--- a/hw/pci.h
+++ b/hw/pci.h
@@ -490,4 +490,7 @@ static inline uint32_t pci_config_size(const PCIDevice *d)
     return pci_is_express(d) ? PCIE_CONFIG_SPACE_SIZE : PCI_CONFIG_SPACE_SIZE;
 }
 
+int pci_check_bar_overlap(PCIDevice *dev,
+                          pcibus_t addr, pcibus_t size, uint8_t type);
+
 #endif
-- 
Anthony PERARD