hw/pci: Trace IRQ routing on PCI topology

Trace how IRQ are rooted from EP to RC.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230211152239.88106-3-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Author: philmd

hw/pci/pci.c

@@ -279,9 +279,13 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change)
 {
     PCIBus *bus;
     for (;;) {
+        int dev_irq = irq_num;
         bus = pci_get_bus(pci_dev);
         assert(bus->map_irq);
         irq_num = bus->map_irq(pci_dev, irq_num);
+        trace_pci_route_irq(dev_irq, DEVICE(pci_dev)->canonical_path, irq_num,
+                            pci_bus_is_root(bus) ? "root-complex"
+                                    : DEVICE(bus->parent_dev)->canonical_path);
         if (bus->set_irq)
             break;
         pci_dev = bus->parent_dev;
@@ -1600,8 +1604,12 @@ PCIINTxRoute pci_device_route_intx_to_irq(PCIDevice *dev, int pin)
     PCIBus *bus;
 
     do {
+        int dev_irq = pin;
         bus = pci_get_bus(dev);
         pin = bus->map_irq(dev, pin);
+        trace_pci_route_irq(dev_irq, DEVICE(dev)->canonical_path, pin,
+                            pci_bus_is_root(bus) ? "root-complex"
+                                    : DEVICE(bus->parent_dev)->canonical_path);
         dev = bus->parent_dev;
     } while (dev);
 

hw/pci/trace-events

@@ -3,6 +3,7 @@
 # pci.c
 pci_update_mappings_del(const char *dev, uint32_t bus, uint32_t slot, uint32_t func, int bar, uint64_t addr, uint64_t size) "%s %02x:%02x.%x %d,0x%"PRIx64"+0x%"PRIx64
 pci_update_mappings_add(const char *dev, uint32_t bus, uint32_t slot, uint32_t func, int bar, uint64_t addr, uint64_t size) "%s %02x:%02x.%x %d,0x%"PRIx64"+0x%"PRIx64
+pci_route_irq(int dev_irq, const char *dev_path, int parent_irq, const char *parent_path) "IRQ %d @%s -> IRQ %d @%s"
 
 # pci_host.c
 pci_cfg_read(const char *dev, uint32_t bus, uint32_t slot, uint32_t func, unsigned offs, unsigned val) "%s %02x:%02x.%x @0x%x -> 0x%x"