From 6775d15de18268718c2f971c2b2d255c76ff2240 Mon Sep 17 00:00:00 2001
From: Jon Doron <arilou@gmail.com>
Date: Fri, 24 Apr 2020 15:34:43 +0300
Subject: [PATCH] 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                |  7 ++++++
 hw/i386/acpi-build.c             | 43 ++++++++++++++++++++++++++++++++
 include/hw/hyperv/vmbus-bridge.h |  3 +++
 3 files changed, 53 insertions(+)

diff --git a/hw/hyperv/vmbus.c b/hw/hyperv/vmbus.c
index 802bbc8c96..2acb2185e8 100644
--- a/hw/hyperv/vmbus.c
+++ b/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;
 }
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 2e15f6848e..dcdfbd8906 100644
--- a/hw/i386/acpi-build.c
+++ b/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);
 }
 
diff --git a/include/hw/hyperv/vmbus-bridge.h b/include/hw/hyperv/vmbus-bridge.h
index 9cc8f780de..c0a06d832c 100644
--- a/include/hw/hyperv/vmbus-bridge.h
+++ b/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;