pci: fix pci_requester_id()

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>

1 files changed, 24 insertions, 2 deletions

diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 4420f47..9ed1624 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -15,6 +15,7 @@
 #define PCI_DEVFN(slot, func)   ((((slot) & 0x1f) << 3) | ((func) & 0x07))
 #define PCI_SLOT(devfn)         (((devfn) >> 3) & 0x1f)
 #define PCI_FUNC(devfn)         ((devfn) & 0x07)
+#define PCI_BUILD_BDF(bus, devfn)     ((bus << 8) | (devfn))
 #define PCI_SLOT_MAX            32
 #define PCI_FUNC_MAX            8
 
@@ -230,6 +231,20 @@ typedef void (*MSIVectorPollNotifier)(PCIDevice *dev,
                                       unsigned int vector_start,
                                       unsigned int vector_end);
 
+enum PCIReqIDType {
+    PCI_REQ_ID_INVALID = 0,
+    PCI_REQ_ID_BDF,
+    PCI_REQ_ID_SECONDARY_BUS,
+    PCI_REQ_ID_MAX,
+};
+typedef enum PCIReqIDType PCIReqIDType;
+
+struct PCIReqIDCache {
+    PCIDevice *dev;
+    PCIReqIDType type;
+};
+typedef struct PCIReqIDCache PCIReqIDCache;
+
 struct PCIDevice {
     DeviceState qdev;
 
@@ -252,6 +267,11 @@ struct PCIDevice {
     /* the following fields are read only */
     PCIBus *bus;
     int32_t devfn;
+    /* Cached device to fetch requester ID from, to avoid the PCI
+     * tree walking every time we invoke PCI request (e.g.,
+     * MSI). For conventional PCI root complex, this field is
+     * meaningless. */
+    PCIReqIDCache requester_id_cache;
     char name[64];
     PCIIORegion io_regions[PCI_NUM_REGIONS];
     AddressSpace bus_master_as;
@@ -692,11 +712,13 @@ static inline uint32_t pci_config_size(const PCIDevice *d)
     return pci_is_express(d) ? PCIE_CONFIG_SPACE_SIZE : PCI_CONFIG_SPACE_SIZE;
 }
 
-static inline uint16_t pci_requester_id(PCIDevice *dev)
+static inline uint16_t pci_get_bdf(PCIDevice *dev)
 {
-    return (pci_bus_num(dev->bus) << 8) | dev->devfn;
+    return PCI_BUILD_BDF(pci_bus_num(dev->bus), dev->devfn);
 }
 
+uint16_t pci_requester_id(PCIDevice *dev);
+
 /* DMA access functions */
 static inline AddressSpace *pci_get_address_space(PCIDevice *dev)
 {