From: Or Idgar <[email protected]>
This patch is a driver which expose the Virtual Machine Generation ID
via sysfs. The ID is a UUID value used to differentiate between virtual
machines.
The VM-Generation ID is a feature defined by Microsoft (paper:
http://go.microsoft.com/fwlink/?LinkId=260709) and supported by multiple
hypervisor vendors.
Signed-off-by: Or Idgar <[email protected]>
---
Changes in v3 from v1 (v2 lack of patch changelog):
- replaced GPL2 section with SPDX line.
- including linux/kobject.h for hypervisor_kobj.
- using acpi_os_map_memory instead acpi_os_map_iomem.
Documentation/ABI/testing/sysfs-hypervisor | 13 +++
drivers/misc/Kconfig | 6 ++
drivers/misc/Makefile | 1 +
drivers/misc/vmgenid.c | 140 +++++++++++++++++++++++++++++
4 files changed, 160 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-hypervisor
create mode 100644 drivers/misc/vmgenid.c
diff --git a/Documentation/ABI/testing/sysfs-hypervisor b/Documentation/ABI/testing/sysfs-hypervisor
new file mode 100644
index 000000000000..2f9a7b8eab70
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-hypervisor
@@ -0,0 +1,13 @@
+What: /sys/hypervisor/vm_gen_counter
+Date: February 2018
+Contact: Or Idgar <[email protected]>
+ Gal Hammer <[email protected]>
+Description: Expose the virtual machine generation ID. The directory
+ contains two files: "generation_id" and "raw". Both files
+ represent the same information.
+
+ "generation_id" file is a UUID string
+ representation.
+
+ "raw" file is a 128-bit integer
+ representation (binary).
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 03605f8fc0dc..5a74802bdfb4 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -500,6 +500,12 @@ config MISC_RTSX
tristate
default MISC_RTSX_PCI || MISC_RTSX_USB
+config VMGENID
+ tristate "Virtual Machine Generation ID driver"
+ help
+ This is a Virtual Machine Generation ID driver which provides
+ a virtual machine unique identifier.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index c3c8624f4d95..067aa666bb6a 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_ASPEED_LPC_SNOOP) += aspeed-lpc-snoop.o
obj-$(CONFIG_PCI_ENDPOINT_TEST) += pci_endpoint_test.o
obj-$(CONFIG_OCXL) += ocxl/
obj-$(CONFIG_MISC_RTSX) += cardreader/
+obj-$(CONFIG_VMGENID) += vmgenid.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_bugs.o
diff --git a/drivers/misc/vmgenid.c b/drivers/misc/vmgenid.c
new file mode 100644
index 000000000000..6b7ec9bd45e8
--- /dev/null
+++ b/drivers/misc/vmgenid.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Virtual Machine Generation ID driver
+ *
+ * Copyright (C) 2018 Red Hat, Inc. All rights reserved.
+ * Authors:
+ * Or Idgar <[email protected]>
+ * Gal Hammer <[email protected]>
+ *
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/acpi.h>
+#include <linux/uuid.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Or Idgar <[email protected]>");
+MODULE_AUTHOR("Gal Hammer <[email protected]>");
+MODULE_DESCRIPTION("Virtual Machine Generation ID");
+MODULE_VERSION("0.1");
+
+ACPI_MODULE_NAME("vmgenid");
+
+static u64 phy_addr;
+
+static ssize_t generation_id_show(struct device *_d,
+ struct device_attribute *attr, char *buf)
+{
+ uuid_t *uuidp;
+ ssize_t result;
+
+ uuidp = acpi_os_map_memory(phy_addr, sizeof(uuid_t));
+ if (!uuidp)
+ return -EFAULT;
+
+ result = sprintf(buf, "%pUl\n", uuidp);
+ acpi_os_unmap_memory(uuidp, sizeof(uuid_t));
+ return result;
+}
+static DEVICE_ATTR_RO(generation_id);
+
+static ssize_t raw_show(struct device *_d,
+ struct device_attribute *attr,
+ char *buf)
+{
+ uuid_t *uuidp;
+
+ uuidp = acpi_os_map_memory(phy_addr, sizeof(uuid_t));
+ if (!uuidp)
+ return -EFAULT;
+ memcpy(buf, uuidp, sizeof(uuid_t));
+ acpi_os_unmap_memory(uuidp, sizeof(uuid_t));
+ return sizeof(uuid_t);
+}
+static DEVICE_ATTR_RO(raw);
+
+static struct attribute *vmgenid_attrs[] = {
+ &dev_attr_generation_id.attr,
+ &dev_attr_raw.attr,
+ NULL,
+};
+static const struct attribute_group vmgenid_group = {
+ .name = "vm_gen_counter",
+ .attrs = vmgenid_attrs,
+};
+
+static int get_vmgenid(acpi_handle handle)
+{
+ int i;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ acpi_status status;
+ union acpi_object *pss;
+ union acpi_object *element;
+
+ status = acpi_evaluate_object(handle, "ADDR", NULL, &buffer);
+ if (ACPI_FAILURE(status)) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _ADDR"));
+ return -ENODEV;
+ }
+ pss = buffer.pointer;
+ if (!pss || pss->type != ACPI_TYPE_PACKAGE || pss->package.count != 2)
+ return -EFAULT;
+
+ phy_addr = 0;
+ for (i = 0; i < pss->package.count; i++) {
+ element = &(pss->package.elements[i]);
+ if (element->type != ACPI_TYPE_INTEGER)
+ return -EFAULT;
+ phy_addr |= element->integer.value << i*32;
+ }
+ return 0;
+}
+
+static int acpi_vmgenid_add(struct acpi_device *device)
+{
+ int retval;
+
+ if (!device)
+ return -EINVAL;
+ retval = get_vmgenid(device->handle);
+ if (retval < 0)
+ return retval;
+ return sysfs_create_group(hypervisor_kobj, &vmgenid_group);
+}
+
+static int acpi_vmgenid_remove(struct acpi_device *device)
+{
+ sysfs_remove_group(hypervisor_kobj, &vmgenid_group);
+ return 0;
+}
+
+static const struct acpi_device_id vmgenid_ids[] = {
+ {"QEMUVGID", 0},
+ {"", 0},
+};
+
+static struct acpi_driver acpi_vmgenid_driver = {
+ .name = "vm_gen_counter",
+ .ids = vmgenid_ids,
+ .owner = THIS_MODULE,
+ .ops = {
+ .add = acpi_vmgenid_add,
+ .remove = acpi_vmgenid_remove,
+ }
+};
+
+static int __init vmgenid_init(void)
+{
+ return acpi_bus_register_driver(&acpi_vmgenid_driver);
+}
+
+static void __exit vmgenid_exit(void)
+{
+ acpi_bus_unregister_driver(&acpi_vmgenid_driver);
+}
+
+module_init(vmgenid_init);
+module_exit(vmgenid_exit);
--
2.14.3
On 02/25/2018 07:55 AM, Or Idgar wrote:
> From: Or Idgar <[email protected]>
>
> This patch is a driver which expose the Virtual Machine Generation ID
> via sysfs. The ID is a UUID value used to differentiate between virtual
> machines.
>
> The VM-Generation ID is a feature defined by Microsoft (paper:
> http://go.microsoft.com/fwlink/?LinkId=260709) and supported by multiple
> hypervisor vendors.
>
> Signed-off-by: Or Idgar <[email protected]>
> ---
>
> Changes in v3 from v1 (v2 lack of patch changelog):
> - replaced GPL2 section with SPDX line.
> - including linux/kobject.h for hypervisor_kobj.
> - using acpi_os_map_memory instead acpi_os_map_iomem.
>
> Documentation/ABI/testing/sysfs-hypervisor | 13 +++
> drivers/misc/Kconfig | 6 ++
> drivers/misc/Makefile | 1 +
> drivers/misc/vmgenid.c | 140 +++++++++++++++++++++++++++++
> 4 files changed, 160 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-hypervisor
> create mode 100644 drivers/misc/vmgenid.c
$Subject says drivers/virt/. Please choose one.
> diff --git a/drivers/misc/vmgenid.c b/drivers/misc/vmgenid.c
> new file mode 100644
> index 000000000000..6b7ec9bd45e8
> --- /dev/null
> +++ b/drivers/misc/vmgenid.c
> @@ -0,0 +1,140 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Virtual Machine Generation ID driver
> + *
> + * Copyright (C) 2018 Red Hat, Inc. All rights reserved.
> + * Authors:
> + * Or Idgar <[email protected]>
> + * Gal Hammer <[email protected]>
> + *
> + */
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/kobject.h>
> +#include <linux/acpi.h>
> +#include <linux/uuid.h>
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Or Idgar <[email protected]>");
> +MODULE_AUTHOR("Gal Hammer <[email protected]>");
> +MODULE_DESCRIPTION("Virtual Machine Generation ID");
> +MODULE_VERSION("0.1");
> +
> +ACPI_MODULE_NAME("vmgenid");
> +
> +static u64 phy_addr;
Minor nit:
I would prefer phys_addr since we also have PHY devices that have a phy addr.
thanks,
--
~Randy