[Qemu-devel] [PATCH V16 3/4] i386: add a Virtual Machine Generation ID device

[Gal Hammer]

Based on Microsoft's specifications (paper can be downloaded from
http://go.microsoft.com/fwlink/?LinkId=260709), add a device
description to the SSDT ACPI table and its implementation.

The GUID is set using a global "vmgenid.uuid" parameter.

Signed-off-by: Gal Hammer <address@hidden>
---
 default-configs/i386-softmmu.mak   |   1 +
 default-configs/x86_64-softmmu.mak |   1 +
 hw/i386/acpi-build.c               |  32 +++++++++
 hw/misc/Makefile.objs              |   1 +
 hw/misc/vmgenid.c                  | 140 +++++++++++++++++++++++++++++++++++++
 include/hw/i386/pc.h               |   3 +
 6 files changed, 178 insertions(+)
 create mode 100644 hw/misc/vmgenid.c

diff --git a/default-configs/i386-softmmu.mak b/default-configs/i386-softmmu.mak
index 91d602c..3c2fda8 100644
--- a/default-configs/i386-softmmu.mak
+++ b/default-configs/i386-softmmu.mak
@@ -48,3 +48,4 @@ CONFIG_MEM_HOTPLUG=y
 CONFIG_XIO3130=y
 CONFIG_IOH3420=y
 CONFIG_I82801B11=y
+CONFIG_VMGENID=y
diff --git a/default-configs/x86_64-softmmu.mak 
b/default-configs/x86_64-softmmu.mak
index 62575eb..36e654d 100644
--- a/default-configs/x86_64-softmmu.mak
+++ b/default-configs/x86_64-softmmu.mak
@@ -49,3 +49,4 @@ CONFIG_MEM_HOTPLUG=y
 CONFIG_XIO3130=y
 CONFIG_IOH3420=y
 CONFIG_I82801B11=y
+CONFIG_VMGENID=y
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index b71e942..784e23d 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -112,6 +112,7 @@ typedef struct AcpiMiscInfo {
     unsigned dsdt_size;
     uint16_t pvpanic_port;
     uint16_t applesmc_io_base;
+    uint64_t vm_generation_addr;
 } AcpiMiscInfo;
 
 typedef struct AcpiBuildPciBusHotplugState {
@@ -238,6 +239,7 @@ static void acpi_get_misc_info(AcpiMiscInfo *info)
     info->tpm_version = tpm_get_version();
     info->pvpanic_port = pvpanic_port();
     info->applesmc_io_base = applesmc_port();
+    info->vm_generation_addr = vm_generation_addr();
 }
 
 /*
@@ -1128,6 +1130,36 @@ build_ssdt(GArray *table_data, GArray *linker,
     }
 
     sb_scope = aml_scope("\\_SB");
+
+    if (misc->vm_generation_addr) {
+        dev = aml_device("VMGI");
+        aml_append(dev, aml_name_decl("_HID", aml_string("QEMU0002")));
+        aml_append(dev,
+            aml_name_decl("_CID", aml_string("VM_Gen_Counter")));
+        aml_append(dev,
+            aml_name_decl("_DDN", aml_string("VM_Gen_Counter")));
+
+        method = aml_method("ADDR", 0);
+        pkg = aml_package(2);
+        aml_append(pkg, aml_int(misc->vm_generation_addr & 0xffffffff));
+        aml_append(pkg, aml_int(misc->vm_generation_addr >> 32));
+        aml_append(method, aml_store(pkg, aml_local(0)));
+        aml_append(method, aml_return(aml_local(0)));
+        aml_append(dev, method);
+
+        aml_append(sb_scope, dev);
+        aml_append(ssdt, sb_scope);
+
+        scope = aml_scope("\\_GPE");
+
+        method = aml_method("_E00", 0);
+        aml_append(method,
+            aml_notify(aml_name("\\_SB.VMGI"), aml_int(0x80)));
+
+        aml_append(scope, method);
+        aml_append(ssdt, scope);
+    }
+
     {
         /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
         dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 4aa76ff..3db11de 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -40,3 +40,4 @@ obj-$(CONFIG_STM32F2XX_SYSCFG) += stm32f2xx_syscfg.o
 
 obj-$(CONFIG_PVPANIC) += pvpanic.o
 obj-$(CONFIG_EDU) += edu.o
+obj-$(CONFIG_VMGENID) += vmgenid.o
diff --git a/hw/misc/vmgenid.c b/hw/misc/vmgenid.c
new file mode 100644
index 0000000..4484952
--- /dev/null
+++ b/hw/misc/vmgenid.c
@@ -0,0 +1,140 @@
+/*
+ *  Virtual Machine Generation ID Device
+ *
+ *  Copyright (C) 2015 Red Hat Inc.
+ *
+ *  Authors: Gal Hammer <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "hw/i386/pc.h"
+#include "hw/acpi/acpi_dev_interface.h"
+
+#define VMGENID_DEVICE "vmgenid"
+
+/* Use the memory address which follows HPET for no special reason. */
+#define VMGENID_DEFAULT_ADDRESS 0xfedf0000
+
+#define PROPERTY_ADDR "addr"
+#define PROPERTY_UUID "uuid"
+
+#define VMGENID(obj) OBJECT_CHECK(VmGenIdState, (obj), VMGENID_DEVICE)
+
+typedef struct VmGenIdState {
+    DeviceState parent_obj;
+    MemoryRegion iomem;
+    uint64_t addr;
+    uint8_t guid[16];
+    bool guid_set;
+} VmGenIdState;
+
+uint64_t vm_generation_addr(void)
+{
+    Object *obj = object_resolve_path_type("", VMGENID_DEVICE, NULL);
+    VmGenIdState *s = VMGENID(obj);
+
+    if (!obj) {
+        return 0;
+    }
+    return s->addr;
+}
+
+static void update_guest(VmGenIdState *s, bool notify)
+{
+    void *ptr = memory_region_get_ram_ptr(&s->iomem);
+    Object *acpi_obj;
+
+    memcpy(ptr, &s->guid, sizeof(s->guid));
+    memory_region_set_dirty(&s->iomem, 0, sizeof(s->guid));
+
+    if (notify) {
+        acpi_obj = object_resolve_path_type("", TYPE_ACPI_DEVICE_IF, NULL);
+        if (acpi_obj) {
+           AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(acpi_obj);
+           AcpiDeviceIf *adev = ACPI_DEVICE_IF(acpi_obj);
+
+           adevc->vm_generation_id_changed(adev);
+        }
+     }
+}
+
+static void vmgenid_set_uuid(Object *obj, const char *value, Error **errp)
+{
+    VmGenIdState *s = VMGENID(obj);
+    bool first_set = !s->guid_set;
+
+    if (qemu_uuid_parse(value, s->guid) < 0) {
+        error_setg(errp, "Fail to parse UUID string.");
+        return;
+    }
+    s->guid_set = true;
+
+    /* Skip the acpi notification when setting the vm generation id for the
+     * first time. This is done because in a q35 machine the gpe register is
+     * allocated after the device is initialized.
+     */
+    update_guest(s, !first_set);
+}
+
+static void vmgenid_realize(DeviceState *qdev, Error **errp)
+{
+    VmGenIdState *s = VMGENID(qdev);
+
+    if (!s->guid_set) {
+        error_setg(errp, "Missing virtual machine generation ID.");
+        return;
+    }
+
+    if (s->addr % 8 != 0) {
+        error_setg(errp, "Address must be 8-byte aligned.");
+        return;
+    }
+
+    vmstate_register_ram(&s->iomem, DEVICE(s));
+    memory_region_add_subregion(get_system_memory(), s->addr, &s->iomem);
+}
+
+static void vmgenid_init(Object *obj)
+{
+    VmGenIdState *s = VMGENID(obj);
+
+    object_property_add_str(obj, PROPERTY_UUID, NULL, vmgenid_set_uuid, NULL);
+
+    memory_region_init_ram(&s->iomem, OBJECT(s), "vm-generation-id", 0x1000,
+        &error_abort);
+}
+
+static Property vmgenid_properties[] = {
+    DEFINE_PROP_UINT64(PROPERTY_ADDR, VmGenIdState, addr,
+                       VMGENID_DEFAULT_ADDRESS),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vmgenid_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = vmgenid_realize;
+    dc->props = vmgenid_properties;
+    dc->hotpluggable = false;
+
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+}
+
+static const TypeInfo vmgenid_device_info = {
+    .name          = VMGENID_DEVICE,
+    .parent        = TYPE_DEVICE,
+    .instance_size = sizeof(VmGenIdState),
+    .instance_init = vmgenid_init,
+    .class_init    = vmgenid_class_init,
+};
+
+static void vmgenid_register_types(void)
+{
+    type_register_static(&vmgenid_device_info);
+}
+
+type_init(vmgenid_register_types)
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 86c5651..9492e32 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -281,6 +281,9 @@ void pc_system_firmware_init(MemoryRegion *rom_memory,
 /* pvpanic.c */
 uint16_t pvpanic_port(void);
 
+/* vmgenid.c */
+uint64_t vm_generation_addr(void);
+
 /* e820 types */
 #define E820_RAM        1
 #define E820_RESERVED   2
-- 
2.1.0