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pci: implement bridge filtering

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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>
This commit is contained in:
Michael S. Tsirkin 2011-09-04 16:50:55 +03:00
parent 778d179939
commit 7df32ca08a
4 changed files with 91 additions and 76 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
hw/pci.c
View File

@ -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)

2
hw/pci.h
View File

@ -90,7 +90,6 @@ typedef struct PCIIORegion {
pcibus_t addr; /* current PCI mapping address. -1 means not mapped */
#define PCI_BAR_UNMAPPED (~(pcibus_t)0)
pcibus_t size;
pcibus_t filtered_size;
uint8_t type;
MemoryRegion *memory;
MemoryRegion *address_space;
@ -273,7 +272,6 @@ int pci_read_devaddr(Monitor *mon, const char *addr, int *domp, int *busp,
void do_pci_info_print(Monitor *mon, const QObject *data);
void do_pci_info(Monitor *mon, QObject **ret_data);
void pci_bridge_update_mappings(PCIBus *b);
void pci_device_deassert_intx(PCIDevice *dev);

92
hw/pci_bridge.c
View File

@ -135,6 +135,77 @@ pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type)
return limit;
}
static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
uint8_t type, const char *name,
MemoryRegion *space,
MemoryRegion *parent_space,
bool enabled)
{
pcibus_t base = pci_bridge_get_base(&bridge->dev, type);
pcibus_t limit = pci_bridge_get_limit(&bridge->dev, type);
/* TODO: this doesn't handle base = 0 limit = 2^64 - 1 correctly.
* Apparently no way to do this with existing memory APIs. */
pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
memory_region_init_alias(alias, name, space, base, size);
memory_region_add_subregion_overlap(parent_space, base, alias, 1);
}
static void pci_bridge_cleanup_alias(MemoryRegion *alias,
MemoryRegion *parent_space)
{
memory_region_del_subregion(parent_space, alias);
memory_region_destroy(alias);
}
static void pci_bridge_region_init(PCIBridge *br)
{
PCIBus *sec_bus = &br->sec_bus;
PCIBus *parent = br->dev.bus;
uint16_t cmd = pci_get_word(br->dev.config + PCI_COMMAND);
pci_bridge_init_alias(br, &br->alias_pref_mem,
PCI_BASE_ADDRESS_MEM_PREFETCH,
"pci_bridge_pref_mem",
sec_bus->address_space_mem,
parent->address_space_mem,
cmd & PCI_COMMAND_MEMORY);
pci_bridge_init_alias(br, &br->alias_mem,
PCI_BASE_ADDRESS_SPACE_MEMORY,
"pci_bridge_mem",
sec_bus->address_space_mem,
parent->address_space_mem,
cmd & PCI_COMMAND_MEMORY);
pci_bridge_init_alias(br, &br->alias_io,
PCI_BASE_ADDRESS_SPACE_IO,
"pci_bridge_io",
sec_bus->address_space_io,
parent->address_space_io,
cmd & PCI_COMMAND_IO);
/* TODO: optinal VGA and VGA palette snooping support. */
}
static void pci_bridge_region_cleanup(PCIBridge *br)
{
PCIBus *parent = br->dev.bus;
pci_bridge_cleanup_alias(&br->alias_io,
parent->address_space_io);
pci_bridge_cleanup_alias(&br->alias_mem,
parent->address_space_mem);
pci_bridge_cleanup_alias(&br->alias_pref_mem,
parent->address_space_mem);
}
static void pci_bridge_update_mappings(PCIBridge *br)
{
/* Make updates atomic to: handle the case of one VCPU updating the bridge
* while another accesses an unaffected region. */
memory_region_transaction_begin();
pci_bridge_region_cleanup(br);
pci_bridge_region_init(br);
memory_region_transaction_commit();
}
/* default write_config function for PCI-to-PCI bridge */
void pci_bridge_write_config(PCIDevice *d,
uint32_t address, uint32_t val, int len)
@ -145,13 +216,15 @@ void pci_bridge_write_config(PCIDevice *d,
pci_default_write_config(d, address, val, len);
if (/* io base/limit */
if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
/* io base/limit */
ranges_overlap(address, len, PCI_IO_BASE, 2) ||
/* memory base/limit, prefetchable base/limit and
io base/limit upper 16 */
ranges_overlap(address, len, PCI_MEMORY_BASE, 20)) {
pci_bridge_update_mappings(&s->sec_bus);
pci_bridge_update_mappings(s);
}
newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
@ -246,10 +319,11 @@ int pci_bridge_initfn(PCIDevice *dev)
br->bus_name);
sec_bus->parent_dev = dev;
sec_bus->map_irq = br->map_irq;
/* TODO: use memory API to perform memory filtering. */
sec_bus->address_space_mem = parent->address_space_mem;
sec_bus->address_space_io = parent->address_space_io;
sec_bus->address_space_mem = g_new(MemoryRegion, 1);
memory_region_init(sec_bus->address_space_mem, "pci_pridge_pci", INT64_MAX);
sec_bus->address_space_io = g_new(MemoryRegion, 1);
memory_region_init(sec_bus->address_space_io, "pci_bridge_io", 65536);
pci_bridge_region_init(br);
QLIST_INIT(&sec_bus->child);
QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
return 0;
@ -259,8 +333,14 @@ int pci_bridge_initfn(PCIDevice *dev)
int pci_bridge_exitfn(PCIDevice *pci_dev)
{
PCIBridge *s = DO_UPCAST(PCIBridge, dev, pci_dev);
PCIBus *sec_bus = &s->sec_bus;
assert(QLIST_EMPTY(&s->sec_bus.child));
QLIST_REMOVE(&s->sec_bus, sibling);
pci_bridge_region_cleanup(s);
memory_region_destroy(sec_bus->address_space_mem);
g_free(sec_bus->address_space_mem);
memory_region_destroy(sec_bus->address_space_io);
g_free(sec_bus->address_space_io);
/* qbus_free() is called automatically by qdev_free() */
return 0;
}

3
hw/pci_internals.h
View File

@ -41,6 +41,9 @@ struct PCIBridge {
/* private member */
PCIBus sec_bus;
MemoryRegion alias_pref_mem;
MemoryRegion alias_mem;
MemoryRegion alias_io;
pci_map_irq_fn map_irq;
const char *bus_name;
};