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pci: fix pci_requester_id()

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This fix SID verification failure when IOMMU IR is enabled with PCI
bridges. Existing pci_requester_id() is more like getting BDF info
only. Renaming it to pci_get_bdf(). Meanwhile, we provide the correct
implementation to get requester ID. VT-d spec 5.1.1 is a good reference
to go, though it talks only about interrupt delivery, the rule works
exactly the same for non-interrupt cases.

Currently, there are three use cases for pci_requester_id():

- PCIX status bits: here we need BDF only, not requester ID. Replacing
  with pci_get_bdf().
- PCIe Error injection and MSI delivery: for both these cases, we are
  looking for requester IDs. Here we should use the new impl.

To avoid a PCI walk every time we send MSI message, one requester_id
cache field is added to PCIDevice to cache the result when initialize
PCI device.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Peter Xu 2016-05-17 19:26:10 +08:00 • committed by Michael S. Tsirkin
parent 49237b856a
commit 4a94b3aa6d
3 changed files with 101 additions and 3 deletions
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76
hw/pci/pci.c
View file

@ -836,6 +836,81 @@ static void do_pci_unregister_device(PCIDevice *pci_dev)
address_space_destroy(&pci_dev->bus_master_as);
}
/* Extract PCIReqIDCache into BDF format */
static uint16_t pci_req_id_cache_extract(PCIReqIDCache *cache)
{
uint8_t bus_n;
uint16_t result;
switch (cache->type) {
case PCI_REQ_ID_BDF:
result = pci_get_bdf(cache->dev);
break;
case PCI_REQ_ID_SECONDARY_BUS:
bus_n = pci_bus_num(cache->dev->bus);
result = PCI_BUILD_BDF(bus_n, 0);
break;
default:
error_printf("Invalid PCI requester ID cache type: %d\n",
cache->type);
exit(1);
break;
}
return result;
}
/* Parse bridges up to the root complex and return requester ID
* cache for specific device. For full PCIe topology, the cache
* result would be exactly the same as getting BDF of the device.
* However, several tricks are required when system mixed up with
* legacy PCI devices and PCIe-to-PCI bridges.
*
* Here we cache the proxy device (and type) not requester ID since
* bus number might change from time to time.
*/
static PCIReqIDCache pci_req_id_cache_get(PCIDevice *dev)
{
PCIDevice *parent;
PCIReqIDCache cache = {
.dev = dev,
.type = PCI_REQ_ID_BDF,
};
while (!pci_bus_is_root(dev->bus)) {
/* We are under PCI/PCIe bridges */
parent = dev->bus->parent_dev;
if (pci_is_express(parent)) {
if (pcie_cap_get_type(parent) == PCI_EXP_TYPE_PCI_BRIDGE) {
/* When we pass through PCIe-to-PCI/PCIX bridges, we
* override the requester ID using secondary bus
* number of parent bridge with zeroed devfn
* (pcie-to-pci bridge spec chap 2.3). */
cache.type = PCI_REQ_ID_SECONDARY_BUS;
cache.dev = dev;
}
} else {
/* Legacy PCI, override requester ID with the bridge's
* BDF upstream. When the root complex connects to
* legacy PCI devices (including buses), it can only
* obtain requester ID info from directly attached
* devices. If devices are attached under bridges, only
* the requester ID of the bridge that is directly
* attached to the root complex can be recognized. */
cache.type = PCI_REQ_ID_BDF;
cache.dev = parent;
}
dev = parent;
}
return cache;
}
uint16_t pci_requester_id(PCIDevice *dev)
{
return pci_req_id_cache_extract(&dev->requester_id_cache);
}
/* -1 for devfn means auto assign */
static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
const char *name, int devfn,
@ -885,6 +960,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
}
pci_dev->devfn = devfn;
pci_dev->requester_id_cache = pci_req_id_cache_get(pci_dev);
dma_as = pci_device_iommu_address_space(pci_dev);
memory_region_init_alias(&pci_dev->bus_master_enable_region,