[PATCH v1 5/5] i386: Hyper-V VMBus ACPI DSDT entry

[Jon Doron <arilou@gmail.com>]

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, so this patch adds two semi-arbitrarily
chosen ones (7 and 13).  This results, in particular, in parallel port
conflicting with vmbus.

TODO: discover and use spare IRQs to avoid conflicts.

Signed-off-by: Evgeny Yakovlev <eyakovlev@virtuozzo.com>
Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Jon Doron <arilou@gmail.com>
---
 hw/i386/acpi-build.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 2a7e55bae7..6d7fdbbe9b 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -43,6 +43,7 @@
 #include "hw/acpi/tpm.h"
 #include "hw/acpi/vmgenid.h"
 #include "hw/boards.h"
+#include "hw/vmbus/vmbus.h"
 #include "sysemu/tpm_backend.h"
 #include "hw/rtc/mc146818rtc_regs.h"
 #include "migration/vmstate.h"
@@ -1270,6 +1271,43 @@ static Aml *build_com_device_aml(uint8_t uid)
     return dev;
 }
 
+static Aml *build_vmbus_device_aml(void)
+{
+    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_store(aml_name("STA"), aml_local(0)));
+    aml_append(method, aml_return(aml_local(0)));
+    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(7));
+    aml_append(crs, aml_irq_no_flags(13));
+    aml_append(dev, aml_name_decl("_CRS", crs));
+
+    return dev;
+}
+
 static void build_isa_devices_aml(Aml *table)
 {
     ISADevice *fdc = pc_find_fdc0();
@@ -1296,6 +1334,10 @@ static void build_isa_devices_aml(Aml *table)
         build_acpi_ipmi_devices(scope, BUS(obj), "\\_SB.PCI0.ISA");
     }
 
+    if (vmbus_exists()) {
+        aml_append(scope, build_vmbus_device_aml());
+    }
+
     aml_append(table, scope);
 }
 
-- 
2.24.1