[Qemu-devel] [PATCH RFC 6/7] hw/acpi: extend acpi pci hotplug support for pci express

[Marcel Apfelbaum <marcel@redhat.com>]

Emit acpi code for pci hotplug on all PC machines:
 - if legacy pci hotpug is enabled (pcihp_bridge_en)
 - if there is at least one legacy pci bridge in current system
 - for PCI buses only (skip PCIe buses)

Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
---
 hw/i386/acpi-build.c | 49 ++++++++++++++++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 17 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 8ae3e53..cc51f9e 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -250,6 +250,11 @@ static void acpi_get_pci_info(PcPciInfo *info)
                                             NULL);
 }
 
+static void acpi_test_pci_bus(PCIBus *bus, void *opaque)
+{
+    *(bool *)opaque |= !pci_bus_is_express(bus);
+}
+
 #define ACPI_PORT_SMI_CMD           0x00b2 /* TODO: this is APM_CNT_IOPORT */
 
 static void acpi_align_size(GArray *blob, unsigned align)
@@ -422,7 +427,7 @@ static void *acpi_set_bsel(PCIBus *bus, void *opaque)
     unsigned *bsel_alloc = opaque;
     unsigned *bus_bsel;
 
-    if (qbus_is_hotpluggable(BUS(bus))) {
+    if (qbus_is_hotpluggable(BUS(bus)) && !pci_bus_is_express(bus)) {
         bus_bsel = g_malloc(sizeof *bus_bsel);
 
         *bus_bsel = (*bsel_alloc)++;
@@ -433,15 +438,12 @@ static void *acpi_set_bsel(PCIBus *bus, void *opaque)
     return bsel_alloc;
 }
 
-static void acpi_set_pci_info(void)
+static void acpi_set_pci_info(PCIBus *bus)
 {
-    PCIBus *bus = find_i440fx(); /* TODO: Q35 support */
     unsigned bsel_alloc = 0;
 
-    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);
-    }
+    /* 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 build_append_pcihp_notify_entry(Aml *method, int slot)
@@ -503,7 +505,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
          * In this case they aren't themselves hot-pluggable.
          * Hotplugged bridges *are* hot-pluggable.
          */
-        bridge_in_acpi = pc->is_bridge && pcihp_bridge_en &&
+        bridge_in_acpi = pc->is_bridge && !pc->is_express && pcihp_bridge_en &&
             !DEVICE(pdev)->hotplugged;
 
         hotplug_enabled_dev = bsel && dc->hotpluggable && !bridge_in_acpi;
@@ -1892,7 +1894,7 @@ static void build_piix4_isa_bridge(Aml *table)
     aml_append(table, scope);
 }
 
-static void build_piix4_pci_hotplug(Aml *table)
+static void build_acpi_pci_hotplug(Aml *table)
 {
     Aml *scope;
     Aml *field;
@@ -1995,6 +1997,7 @@ build_dsdt(GArray *table_data, GArray *linker,
     uint32_t nr_mem = machine->ram_slots;
     int root_bus_limit = 0xFF;
     PCIBus *root_bus = NULL;
+    bool has_pci_bus = false;
     int i;
 
     dsdt = init_aml_allocator();
@@ -2016,7 +2019,6 @@ build_dsdt(GArray *table_data, GArray *linker,
         build_piix4_pm(dsdt);
         build_piix4_isa_bridge(dsdt);
         build_isa_devices_aml(dsdt);
-        build_piix4_pci_hotplug(dsdt);
         build_piix4_pci0_int(dsdt);
     } else {
         sb_scope = aml_scope("_SB");
@@ -2040,6 +2042,11 @@ build_dsdt(GArray *table_data, GArray *linker,
     root_bus = PC_MACHINE(machine)->bus;
     assert(root_bus);
 
+    pci_for_each_bus(root_bus, acpi_test_pci_bus, &has_pci_bus);
+    if (pm->pcihp_bridge_en && has_pci_bus) {
+        build_acpi_pci_hotplug(dsdt);
+    }
+
     build_cpu_hotplug_aml(dsdt);
     build_memory_hotplug_aml(dsdt, nr_mem, pm->mem_hp_io_base,
                              pm->mem_hp_io_len);
@@ -2050,7 +2057,7 @@ build_dsdt(GArray *table_data, GArray *linker,
 
         aml_append(scope, aml_method("_L00", 0, AML_NOTSERIALIZED));
 
-        if (misc->is_piix4) {
+        if (pm->pcihp_bridge_en && has_pci_bus) {
             method = aml_method("_E01", 0, AML_NOTSERIALIZED);
             aml_append(method,
                 aml_acquire(aml_name("\\_SB.PCI0.BLCK"), 0xFFFF));
@@ -2188,7 +2195,7 @@ build_dsdt(GArray *table_data, GArray *linker,
     g_ptr_array_free(mem_ranges, true);
 
     /* reserve PCIHP resources */
-    if (pm->pcihp_io_len) {
+    if (pm->pcihp_bridge_en && has_pci_bus && pm->pcihp_io_len) {
         dev = aml_device("PHPR");
         aml_append(dev, aml_name_decl("_HID", aml_string("PNP0A06")));
         aml_append(dev,
@@ -2326,10 +2333,14 @@ build_dsdt(GArray *table_data, GArray *linker,
 
         {
             Aml *scope = aml_scope("PCI0");
+            bool scope_used = false;
 
-            /* Scan all PCI buses. Generate tables to support hotplug. */
-            build_append_pci_bus_devices(scope, root_bus,
-                                         pm->pcihp_bridge_en);
+            if (pm->pcihp_bridge_en && has_pci_bus) {
+                /* Scan all PCI buses. Generate tables to support hotplug. */
+                build_append_pci_bus_devices(scope, root_bus,
+                                             pm->pcihp_bridge_en);
+                scope_used = true;
+            }
 
             if (misc->tpm_version != TPM_VERSION_UNSPEC) {
                 dev = aml_device("ISA.TPM");
@@ -2346,8 +2357,12 @@ build_dsdt(GArray *table_data, GArray *linker,
                 /* aml_append(crs, aml_irq_no_flags(TPM_TIS_IRQ)); */
                 aml_append(dev, aml_name_decl("_CRS", crs));
                 aml_append(scope, dev);
+                scope_used = true;
+            }
+
+            if (scope_used) {
+                aml_append(sb_scope, scope);
             }
-            aml_append(sb_scope, scope);
         }
         aml_append(dsdt, sb_scope);
     }
@@ -2870,7 +2885,7 @@ void acpi_setup(void)
 
     build_state = g_malloc0(sizeof *build_state);
 
-    acpi_set_pci_info();
+    acpi_set_pci_info(pcms->bus);
 
     acpi_build_tables_init(&tables);
     acpi_build(&tables, MACHINE(pcms));
-- 
2.4.3