pci: implement bridge filtering

Support bridge filtering on top of the memory
API as suggested by Avi Kivity:

Create a memory region for the bridge's address space.  This region is
not directly added to system_memory or its descendants.  Devices under
the bridge see this region as its pci_address_space().  The region is
as large as the entire address space - it does not take into account
any windows.

For each of the three windows (pref, non-pref, vga), create an alias
with the appropriate start and size.  Map the alias into the bridge's
parent's pci_address_space(), as subregions.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 68 deletions

diff --git a/hw/pci.c b/hw/pci.c
index 07659632c5..5c4f071d28 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -878,7 +878,6 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
     r = &pci_dev->io_regions[region_num];
     r->addr = PCI_BAR_UNMAPPED;
     r->size = size;
-    r->filtered_size = size;
     r->type = type;
     r->memory = NULL;
 
@@ -909,41 +908,6 @@ pcibus_t pci_get_bar_addr(PCIDevice *pci_dev, int region_num)
     return pci_dev->io_regions[region_num].addr;
 }
 
-static void pci_bridge_filter(PCIDevice *d, pcibus_t *addr, pcibus_t *size,
-                              uint8_t type)
-{
-    pcibus_t base = *addr;
-    pcibus_t limit = *addr + *size - 1;
-    PCIDevice *br;
-
-    for (br = d->bus->parent_dev; br; br = br->bus->parent_dev) {
-        uint16_t cmd = pci_get_word(d->config + PCI_COMMAND);
-
-        if (type & PCI_BASE_ADDRESS_SPACE_IO) {
-            if (!(cmd & PCI_COMMAND_IO)) {
-                goto no_map;
-            }
-        } else {
-            if (!(cmd & PCI_COMMAND_MEMORY)) {
-                goto no_map;
-            }
-        }
-
-        base = MAX(base, pci_bridge_get_base(br, type));
-        limit = MIN(limit, pci_bridge_get_limit(br, type));
-    }
-
-    if (base > limit) {
-        goto no_map;
-    }
-    *addr = base;
-    *size = limit - base + 1;
-    return;
-no_map:
-    *addr = PCI_BAR_UNMAPPED;
-    *size = 0;
-}
-
 static pcibus_t pci_bar_address(PCIDevice *d,
 				int reg, uint8_t type, pcibus_t size)
 {
@@ -1013,7 +977,7 @@ static void pci_update_mappings(PCIDevice *d)
 {
     PCIIORegion *r;
     int i;
-    pcibus_t new_addr, filtered_size;
+    pcibus_t new_addr;
 
     for(i = 0; i < PCI_NUM_REGIONS; i++) {
         r = &d->io_regions[i];
@@ -1024,14 +988,8 @@ static void pci_update_mappings(PCIDevice *d)
 
         new_addr = pci_bar_address(d, i, r->type, r->size);
 
-        /* bridge filtering */
-        filtered_size = r->size;
-        if (new_addr != PCI_BAR_UNMAPPED) {
-            pci_bridge_filter(d, &new_addr, &filtered_size, r->type);
-        }
-
         /* This bar isn't changed */
-        if (new_addr == r->addr && filtered_size == r->filtered_size)
+        if (new_addr == r->addr)
             continue;
 
         /* now do the real mapping */
@@ -1039,15 +997,7 @@ static void pci_update_mappings(PCIDevice *d)
             memory_region_del_subregion(r->address_space, r->memory);
         }
         r->addr = new_addr;
-        r->filtered_size = filtered_size;
         if (r->addr != PCI_BAR_UNMAPPED) {
-            /*
-             * TODO: currently almost all the map funcions assumes
-             * filtered_size == size and addr & ~(size - 1) == addr.
-             * However with bridge filtering, they aren't always true.
-             * Teach them such cases, such that filtered_size < size and
-             * addr & (size - 1) != 0.
-             */
             if (r->type & PCI_BASE_ADDRESS_SPACE_IO) {
                 memory_region_add_subregion_overlap(r->address_space,
                                                     r->addr,
@@ -1564,22 +1514,6 @@ PCIDevice *pci_nic_init_nofail(NICInfo *nd, const char *default_model,
     return res;
 }
 
-static void pci_bridge_update_mappings_fn(PCIBus *b, PCIDevice *d)
-{
-    pci_update_mappings(d);
-}
-
-void pci_bridge_update_mappings(PCIBus *b)
-{
-    PCIBus *child;
-
-    pci_for_each_device_under_bus(b, pci_bridge_update_mappings_fn);
-
-    QLIST_FOREACH(child, &b->child, sibling) {
-        pci_bridge_update_mappings(child);
-    }
-}
-
 /* Whether a given bus number is in range of the secondary
  * bus of the given bridge device. */
 static bool pci_secondary_bus_in_range(PCIDevice *dev, int bus_num)