1 files changed, 56 insertions, 2 deletions

diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 9dc4d3e2db..ceab287bd3 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -39,12 +39,13 @@
 #include "trace.h"
 
 #define ACPI_PCIHP_ADDR 0xae00
-#define ACPI_PCIHP_SIZE 0x0014
+#define ACPI_PCIHP_SIZE 0x0018
 #define PCI_UP_BASE 0x0000
 #define PCI_DOWN_BASE 0x0004
 #define PCI_EJ_BASE 0x0008
 #define PCI_RMV_BASE 0x000c
 #define PCI_SEL_BASE 0x0010
+#define PCI_AIDX_BASE 0x0014
 
 typedef struct AcpiPciHpFind {
     int bsel;
@@ -251,9 +252,13 @@ void acpi_pcihp_reset(AcpiPciHpState *s, bool acpihp_root_off)
     acpi_pcihp_update(s);
 }
 
+#define ONBOARD_INDEX_MAX (16 * 1024 - 1)
+
 void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
                                    DeviceState *dev, Error **errp)
 {
+    PCIDevice *pdev = PCI_DEVICE(dev);
+
     /* Only hotplugged devices need the hotplug capability. */
     if (dev->hotplugged &&
         acpi_pcihp_get_bsel(pci_get_bus(PCI_DEVICE(dev))) < 0) {
@@ -261,6 +266,17 @@ void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
                    ACPI_PCIHP_PROP_BSEL "' set");
         return;
     }
+
+    /*
+     * capped by systemd (see: udev-builtin-net_id.c)
+     * as it's the only known user honor it to avoid users
+     * misconfigure QEMU and then wonder why acpi-index doesn't work
+     */
+    if (pdev->acpi_index > ONBOARD_INDEX_MAX) {
+        error_setg(errp, "acpi-index should be less or equal to %u",
+                   ONBOARD_INDEX_MAX);
+        return;
+    }
 }
 
 void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
@@ -347,7 +363,6 @@ static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
         trace_acpi_pci_down_read(val);
         break;
     case PCI_EJ_BASE:
-        /* No feature defined yet */
         trace_acpi_pci_features_read(val);
         break;
     case PCI_RMV_BASE:
@@ -357,6 +372,12 @@ static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
     case PCI_SEL_BASE:
         val = s->hotplug_select;
         trace_acpi_pci_sel_read(val);
+        break;
+    case PCI_AIDX_BASE:
+        val = s->acpi_index;
+        s->acpi_index = 0;
+        trace_acpi_pci_acpi_index_read(val);
+        break;
     default:
         break;
     }
@@ -367,8 +388,35 @@ static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
                       unsigned int size)
 {
+    int slot;
+    PCIBus *bus;
+    BusChild *kid, *next;
     AcpiPciHpState *s = opaque;
+
+    s->acpi_index = 0;
     switch (addr) {
+    case PCI_AIDX_BASE:
+        /*
+         * fetch acpi-index for specified slot so that follow up read from
+         * PCI_AIDX_BASE can return it to guest
+         */
+        slot = ctz32(data);
+
+        if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
+            break;
+        }
+
+        bus = acpi_pcihp_find_hotplug_bus(s, s->hotplug_select);
+        QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
+            Object *o = OBJECT(kid->child);
+            PCIDevice *dev = PCI_DEVICE(o);
+            if (PCI_SLOT(dev->devfn) == slot) {
+                s->acpi_index = object_property_get_uint(o, "acpi-index", NULL);
+                break;
+            }
+        }
+        trace_acpi_pci_acpi_index_write(s->hotplug_select, slot, s->acpi_index);
+        break;
     case PCI_EJ_BASE:
         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
             break;
@@ -413,6 +461,12 @@ void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
                                    OBJ_PROP_FLAG_READ);
 }
 
+bool vmstate_acpi_pcihp_use_acpi_index(void *opaque, int version_id)
+{
+     AcpiPciHpState *s = opaque;
+     return s->acpi_index;
+}
+
 const VMStateDescription vmstate_acpi_pcihp_pci_status = {
     .name = "acpi_pcihp_pci_status",
     .version_id = 1,