i386: Hyper-V VMBus ACPI DSDT entry

Guest OS uses ACPI to discover VMBus presence.  Add a corresponding
entry to DSDT in case VMBus has been enabled.

Experimentally Windows guests were found to require this entry to
include two IRQ resources. They seem to never be used but they still
have to be there.

Make IRQ numbers user-configurable via corresponding properties; use 7
and 13 by default.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
Message-Id: <20200424123444.3481728-6-arilou@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/hyperv/vmbus.c

@@ -2641,6 +2641,12 @@ static const VMStateDescription vmstate_vmbus_bridge = {
     },
 };
 
+static Property vmbus_bridge_props[] = {
+    DEFINE_PROP_UINT8("irq0", VMBusBridge, irq0, 7),
+    DEFINE_PROP_UINT8("irq1", VMBusBridge, irq1, 13),
+    DEFINE_PROP_END_OF_LIST()
+};
+
 static void vmbus_bridge_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
@@ -2651,6 +2657,7 @@ static void vmbus_bridge_class_init(ObjectClass *klass, void *data)
     sk->explicit_ofw_unit_address = vmbus_bridge_ofw_unit_address;
     set_bit(DEVICE_CATEGORY_BRIDGE, k->categories);
     k->vmsd = &vmstate_vmbus_bridge;
+    device_class_set_props(k, vmbus_bridge_props);
     /* override SysBusDevice's default */
     k->user_creatable = true;
 }

hw/i386/acpi-build.c

@@ -50,6 +50,7 @@
 #include "hw/mem/nvdimm.h"
 #include "sysemu/numa.h"
 #include "sysemu/reset.h"
+#include "hw/hyperv/vmbus-bridge.h"
 
 /* Supported chipsets: */
 #include "hw/southbridge/piix.h"
@@ -1270,9 +1271,47 @@ static Aml *build_com_device_aml(uint8_t uid)
     return dev;
 }
 
+static Aml *build_vmbus_device_aml(VMBusBridge *vmbus_bridge)
+{
+    Aml *dev;
+    Aml *method;
+    Aml *crs;
+
+    dev = aml_device("VMBS");
+    aml_append(dev, aml_name_decl("STA", aml_int(0xF)));
+    aml_append(dev, aml_name_decl("_HID", aml_string("VMBus")));
+    aml_append(dev, aml_name_decl("_UID", aml_int(0x0)));
+    aml_append(dev, aml_name_decl("_DDN", aml_string("VMBUS")));
+
+    method = aml_method("_DIS", 0, AML_NOTSERIALIZED);
+    aml_append(method, aml_store(aml_and(aml_name("STA"), aml_int(0xD), NULL),
+                                     aml_name("STA")));
+    aml_append(dev, method);
+
+    method = aml_method("_PS0", 0, AML_NOTSERIALIZED);
+    aml_append(method, aml_store(aml_or(aml_name("STA"), aml_int(0xF), NULL),
+                                     aml_name("STA")));
+    aml_append(dev, method);
+
+    method = aml_method("_STA", 0, AML_NOTSERIALIZED);
+    aml_append(method, aml_return(aml_name("STA")));
+    aml_append(dev, method);
+
+    aml_append(dev, aml_name_decl("_PS3", aml_int(0x0)));
+
+    crs = aml_resource_template();
+    aml_append(crs, aml_irq_no_flags(vmbus_bridge->irq0));
+    /* FIXME: newer HyperV gets by with only one IRQ */
+    aml_append(crs, aml_irq_no_flags(vmbus_bridge->irq1));
+    aml_append(dev, aml_name_decl("_CRS", crs));
+
+    return dev;
+}
+
 static void build_isa_devices_aml(Aml *table)
 {
     ISADevice *fdc = pc_find_fdc0();
+    VMBusBridge *vmbus_bridge = vmbus_bridge_find();
     bool ambiguous;
 
     Aml *scope = aml_scope("_SB.PCI0.ISA");
@@ -1297,6 +1336,10 @@ static void build_isa_devices_aml(Aml *table)
         isa_build_aml(ISA_BUS(obj), scope);
     }
 
+    if (vmbus_bridge) {
+        aml_append(scope, build_vmbus_device_aml(vmbus_bridge));
+    }
+
     aml_append(table, scope);
 }
 

include/hw/hyperv/vmbus-bridge.h

@@ -19,6 +19,9 @@ typedef struct VMBus VMBus;
 typedef struct VMBusBridge {
     SysBusDevice parent_obj;
 
+    uint8_t irq0;
+    uint8_t irq1;
+
     VMBus *bus;
 } VMBusBridge;