hw/acpi: Move acpi_set_pci_info to pcihp

HW part of ACPI PCI hotplug in QEMU depends on ACPI_PCIHP_PROP_BSEL
being set on a PCI bus that supports ACPI hotplug. It should work
regardless of the source of ACPI tables (QEMU generator/legacy SeaBIOS/Xen).
So move ACPI_PCIHP_PROP_BSEL initialization into HW ACPI implementation
part from QEMU's ACPI table generator.

To do PCI passthrough with Xen, the property ACPI_PCIHP_PROP_BSEL needs
to be set, but this was done only when ACPI tables are built which is
not needed for a Xen guest. The need for the property starts with commit
"pc: pcihp: avoid adding ACPI_PCIHP_PROP_BSEL twice"
(f0c9d64a68b776374ec4732424a3e27753ce37b6).

Adding find_i440fx into stubs so that mips-softmmu target can be built.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/hw/acpi/pcihp.c b/hw/acpi/pcihp.c
index 9db3c2eaf2..7da51c0569 100644
--- a/hw/acpi/pcihp.c
+++ b/hw/acpi/pcihp.c
@@ -75,6 +75,43 @@ static int acpi_pcihp_get_bsel(PCIBus *bus)
     }
 }
 
+/* Assign BSEL property to all buses.  In the future, this can be changed
+ * to only assign to buses that support hotplug.
+ */
+static void *acpi_set_bsel(PCIBus *bus, void *opaque)
+{
+    unsigned *bsel_alloc = opaque;
+    unsigned *bus_bsel;
+
+    if (qbus_is_hotpluggable(BUS(bus))) {
+        bus_bsel = g_malloc(sizeof *bus_bsel);
+
+        *bus_bsel = (*bsel_alloc)++;
+        object_property_add_uint32_ptr(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
+                                       bus_bsel, &error_abort);
+    }
+
+    return bsel_alloc;
+}
+
+static void acpi_set_pci_info(void)
+{
+    static bool bsel_is_set;
+    PCIBus *bus;
+    unsigned bsel_alloc = ACPI_PCIHP_BSEL_DEFAULT;
+
+    if (bsel_is_set) {
+        return;
+    }
+    bsel_is_set = true;
+
+    bus = find_i440fx(); /* TODO: Q35 support */
+    if (bus) {
+        /* Scan all PCI buses. Set property to enable acpi based hotplug. */
+        pci_for_each_bus_depth_first(bus, acpi_set_bsel, NULL, &bsel_alloc);
+    }
+}
+
 static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
 {
     AcpiPciHpFind *find = opaque;
@@ -177,6 +214,7 @@ static void acpi_pcihp_update(AcpiPciHpState *s)
 
 void acpi_pcihp_reset(AcpiPciHpState *s)
 {
+    acpi_set_pci_info();
     acpi_pcihp_update(s);
 }