[v6,7/7] tests: Add unit tests for the VM Generation ID feature

Commit Message

[e-mail] Feb. 15, 2017, 6:15 a.m. UTC

From: Ben Warren <[e-mail]>

The following tests are implemented:
* test that a GUID passed in by command line is propagated to the guest.
* test that changing the GUID at runtime via the monitor is reflected in
  the guest.
* test that the "auto" argument to the GUID generates a different, and
  correct GUID as seen by the guest.

  This patch is loosely based on a previous patch from:
  Gal Hammer <[e-mail]>  and Igor Mammedov <[e-mail]>

Signed-off-by: Ben Warren <[e-mail]>
---
 tests/Makefile.include |   2 +
 tests/vmgenid-test.c   | 195 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 197 insertions(+)
 create mode 100644 tests/vmgenid-test.c

Comments

Igor Mammedov Feb. 15, 2017, 1:13 p.m. UTC | #1

On Tue, 14 Feb 2017 22:15:49 -0800
[e-mail] wrote:

> From: Ben Warren <[e-mail]>
> 
> The following tests are implemented:
> * test that a GUID passed in by command line is propagated to the guest.
> * test that changing the GUID at runtime via the monitor is reflected in
>   the guest.
> * test that the "auto" argument to the GUID generates a different, and
>   correct GUID as seen by the guest.
> 
>   This patch is loosely based on a previous patch from:
>   Gal Hammer <[e-mail]>  and Igor Mammedov <[e-mail]>
> 
> Signed-off-by: Ben Warren <[e-mail]>
> ---
>  tests/Makefile.include |   2 +
>  tests/vmgenid-test.c   | 195 +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 197 insertions(+)
>  create mode 100644 tests/vmgenid-test.c
> 
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index 634394a..ca4b3f7 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -241,6 +241,7 @@ check-qtest-i386-y += tests/usb-hcd-xhci-test$(EXESUF)
>  gcov-files-i386-y += hw/usb/hcd-xhci.c
>  check-qtest-i386-y += tests/pc-cpu-test$(EXESUF)
>  check-qtest-i386-y += tests/q35-test$(EXESUF)
> +check-qtest-i386-y += tests/vmgenid-test$(EXESUF)
>  gcov-files-i386-y += hw/pci-host/q35.c
>  check-qtest-i386-$(CONFIG_VHOST_NET_TEST_i386) += tests/vhost-user-test$(EXESUF)
>  ifeq ($(CONFIG_VHOST_NET_TEST_i386),)
> @@ -726,6 +727,7 @@ tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem
>  tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o contrib/libvhost-user/libvhost-user.o $(test-util-obj-y)
>  tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
>  tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
> +tests/vmgenid-test$(EXESUF): tests/vmgenid-test.o
>  
>  tests/migration/stress$(EXESUF): tests/migration/stress.o
>  	$(call quiet-command, $(LINKPROG) -static -O3 $(PTHREAD_LIB) -o $@ $< ,"LINK","$(TARGET_DIR)$@")
> diff --git a/tests/vmgenid-test.c b/tests/vmgenid-test.c
> new file mode 100644
> index 0000000..721ba05
> --- /dev/null
> +++ b/tests/vmgenid-test.c
> @@ -0,0 +1,195 @@
> +/*
> + * QTest testcase for VM Generation ID
> + *
> + * Copyright (c) 2016 Red Hat, Inc.
> + * Copyright (c) 2017 Skyport Systems
> + *
> + * 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 <glib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include "qemu/osdep.h"
> +#include "qemu/bitmap.h"
> +#include "qemu/uuid.h"
> +#include "hw/acpi/acpi-defs.h"
> +#include "acpi-utils.h"
> +#include "libqtest.h"
> +
> +#define VGID_GUID "324e6eaf-d1d1-4bf6-bf41-b9bb6c91fb87"
> +#define VMGENID_GUID_OFFSET      40   /* allow space for
> +                                       * OVMF SDT Header Probe Supressor
> +                                       */
> +
> +static uint32_t vgia;
> +
> +typedef struct {
> +    AcpiTableHeader header;
> +    gchar name_op;
> +    gchar vgia[4];
> +    gchar val_op;
> +    uint32_t vgia_val;
> +} QEMU_PACKED VgidTable;
> +
> +static uint32_t find_vgia(void)
> +{
[...]

===
> +    /* First, find the RSDP */
> +    for (off = 0xf0000; off < 0x100000; off += 0x10) {
> +        uint8_t sig[] = "RSD PTR ";
> +
> +        for (i = 0; i < sizeof sig - 1; ++i) {
> +            sig[i] = readb(off + i);
> +        }
> +
> +        if (!memcmp(sig, "RSD PTR ", sizeof sig)) {
> +            break;
> +        }
> +    }
> +    g_assert_cmphex(off, <, 0x100000);
> +
> +    /* Parse the RSDP header so we can find the RSDT */
> +    ACPI_READ_FIELD(rsdp_table.signature, off);
> +    ACPI_ASSERT_CMP64(rsdp_table.signature, "RSD PTR ");
> +
> +    ACPI_READ_FIELD(rsdp_table.checksum, off);
> +    ACPI_READ_ARRAY(rsdp_table.oem_id, off);
> +    ACPI_READ_FIELD(rsdp_table.revision, off);
> +    ACPI_READ_FIELD(rsdp_table.rsdt_physical_address, off);
> +
> +    rsdt = rsdp_table.rsdt_physical_address;
> +    /* read the header */
> +    ACPI_READ_TABLE_HEADER(&rsdt_table, rsdt);
> +    ACPI_ASSERT_CMP(rsdt_table.signature, "RSDT");
> +
> +    /* compute the table entries in rsdt */
> +    tables_nr = (rsdt_table.length - sizeof(AcpiRsdtDescriptorRev1)) /
> +                sizeof(uint32_t);
> +    g_assert_cmpint(tables_nr, >, 0);
> +
> +    /* get the addresses of the tables pointed by rsdt */
> +    tables = g_new0(uint32_t, tables_nr);
> +    ACPI_READ_ARRAY_PTR(tables, tables_nr, rsdt);
===
above is duplicated code from bios-tables-test.c
please extract it into separate functions and use them in both tests.

> +    for (i = 0; i < tables_nr; i++) {
> +        ACPI_READ_TABLE_HEADER(&ssdt_table, tables[i]);
> +        if (!strncmp((char *)ssdt_table.oem_table_id, "VMGENID", 7)) {
> +            /* the first entry in the table should be VGIA
> +             * That's all we need
> +             */
> +            ACPI_READ_FIELD(vgid_table.name_op, tables[i]);
> +            g_assert(vgid_table.name_op == 0x08);  /* name */
> +            ACPI_READ_ARRAY(vgid_table.vgia, tables[i]);
> +            g_assert(memcmp(vgid_table.vgia, "VGIA", 4) == 0);
> +            ACPI_READ_FIELD(vgid_table.val_op, tables[i]);
> +            g_assert(vgid_table.val_op == 0x0C);  /* dword */
> +            ACPI_READ_FIELD(vgid_table.vgia_val, tables[i]);
> +            /* The GUID is written at a fixed offset into the fw_cfg file
> +             * in order to implement the "OVMF SDT Header probe suppressor"
> +             * see docs/specs/vmgenid.txt for more details
> +             */
> +            return vgid_table.vgia_val + VMGENID_GUID_OFFSET;
> +        }
> +    }
> +    return 0;
> +}
> +
> +static void vmgenid_read_guid(QemuUUID *guid)
> +{
> +    int i;
> +
> +    if (vgia == 0) {
> +        vgia = find_vgia();
> +    }
> +    g_assert(vgia);
> +
> +    /* Read the GUID directly from guest memory */
> +    for (i = 0; i < 16; i++) {
> +        guid->data[i] = readb(vgia + i);
> +    }
> +    /* The GUID is in little-endian format in the guest, while QEMU
> +     * uses big-endian.  Swap after reading.
> +     */
> +    qemu_uuid_bswap(guid);
> +}
> +
> +static void vmgenid_test(void)
> +{
> +    QemuUUID expected, measured;
> +    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
> +    vmgenid_read_guid(&measured);
> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) == 0);
> +}
> +
> +static void vmgenid_set_guid_test(void)
> +{
> +    QDict *response;
> +    gchar *cmd;
> +    QemuUUID expected, measured;
> +    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
> +    /* Change the GUID slightly */
> +    expected.data[0] += 1;
> +
> +    cmd = g_strdup_printf("{ 'execute': 'qom-set', 'arguments': { "
> +                   "'path': '/machine/peripheral/testvgid', "
> +                   "'property': 'guid', 'value': '%s' } }",
> +                   qemu_uuid_unparse_strdup(&expected));
> +    response = qmp(cmd);
> +    g_assert(qdict_haskey(response, "return"));
> +    QDECREF(response);
> +
> +    vmgenid_read_guid(&measured);
> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) == 0);
> +}
> +
> +static void vmgenid_set_guid_auto_test(void)
> +{
> +    QDict *response;
> +    QemuUUID expected, measured;
> +
> +    /* Read the initial value */
> +    vmgenid_read_guid(&expected);
> +
> +    /* Setting to 'auto' generates a random GUID */
> +    response = qmp("{ 'execute': 'qom-set', 'arguments': { "
> +                   "'path': '/machine/peripheral/testvgid', "
> +                   "'property': 'guid', 'value': 'auto' } }");
> +
> +    g_assert(qdict_haskey(response, "return"));
> +    QDECREF(response);
> +
> +    vmgenid_read_guid(&measured);
> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) != 0);
> +}
> +
> +int main(int argc, char **argv)
> +{
> +    int ret;
> +    gchar *cmd;
> +
> +    g_test_init(&argc, &argv, NULL);
> +
> +    cmd = g_strdup_printf("-machine accel=tcg -device vmgenid,id=testvgid,"
> +                          "guid=%s", VGID_GUID);
> +    qtest_start(cmd);
> +    qtest_add_func("/vmgenid/vmgenid", vmgenid_test);
> +    qtest_add_func("/vmgenid/vmgenid/set-guid", vmgenid_set_guid_test);
this is probably no necessary as you've dropped dynamic set in v6,
so if this test passes it's a bug in vmgenid and you should forbid
setting property after device is realized.
See how qdev_prop_set_after_realize() is used.

> +    qtest_add_func("/vmgenid/vmgenid/set-guid-auto",
> +                   vmgenid_set_guid_auto_test);
this should be replaced with this first test but with 'auto' value

maybe add query-vm-generation-id test

> +    ret = g_test_run();
> +
> +    qtest_end();
> +
> +    return ret;
> +}

[e-mail] Feb. 16, 2017, 6:15 a.m. UTC | #2

> On Feb 15, 2017, at 5:13 AM, Igor Mammedov <[e-mail]> wrote:
> 
> On Tue, 14 Feb 2017 22:15:49 -0800
> [e-mail] <mailto:[e-mail]> wrote:
> 
>> From: Ben Warren <[e-mail]>
>> 
>> The following tests are implemented:
>> * test that a GUID passed in by command line is propagated to the guest.
>> * test that changing the GUID at runtime via the monitor is reflected in
>>  the guest.
>> * test that the "auto" argument to the GUID generates a different, and
>>  correct GUID as seen by the guest.
>> 
>>  This patch is loosely based on a previous patch from:
>>  Gal Hammer <[e-mail]>  and Igor Mammedov <[e-mail]>
>> 
>> Signed-off-by: Ben Warren <[e-mail]>
>> ---
>> tests/Makefile.include |   2 +
>> tests/vmgenid-test.c   | 195 +++++++++++++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 197 insertions(+)
>> create mode 100644 tests/vmgenid-test.c
>> 
>> diff --git a/tests/Makefile.include b/tests/Makefile.include
>> index 634394a..ca4b3f7 100644
>> --- a/tests/Makefile.include
>> +++ b/tests/Makefile.include
>> @@ -241,6 +241,7 @@ check-qtest-i386-y += tests/usb-hcd-xhci-test$(EXESUF)
>> gcov-files-i386-y += hw/usb/hcd-xhci.c
>> check-qtest-i386-y += tests/pc-cpu-test$(EXESUF)
>> check-qtest-i386-y += tests/q35-test$(EXESUF)
>> +check-qtest-i386-y += tests/vmgenid-test$(EXESUF)
>> gcov-files-i386-y += hw/pci-host/q35.c
>> check-qtest-i386-$(CONFIG_VHOST_NET_TEST_i386) += tests/vhost-user-test$(EXESUF)
>> ifeq ($(CONFIG_VHOST_NET_TEST_i386),)
>> @@ -726,6 +727,7 @@ tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem
>> tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o contrib/libvhost-user/libvhost-user.o $(test-util-obj-y)
>> tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
>> tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
>> +tests/vmgenid-test$(EXESUF): tests/vmgenid-test.o
>> 
>> tests/migration/stress$(EXESUF): tests/migration/stress.o
>> 	$(call quiet-command, $(LINKPROG) -static -O3 $(PTHREAD_LIB) -o $@ $< ,"LINK","$(TARGET_DIR)$@")
>> diff --git a/tests/vmgenid-test.c b/tests/vmgenid-test.c
>> new file mode 100644
>> index 0000000..721ba05
>> --- /dev/null
>> +++ b/tests/vmgenid-test.c
>> @@ -0,0 +1,195 @@
>> +/*
>> + * QTest testcase for VM Generation ID
>> + *
>> + * Copyright (c) 2016 Red Hat, Inc.
>> + * Copyright (c) 2017 Skyport Systems
>> + *
>> + * 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 <glib.h>
>> +#include <string.h>
>> +#include <unistd.h>
>> +#include "qemu/osdep.h"
>> +#include "qemu/bitmap.h"
>> +#include "qemu/uuid.h"
>> +#include "hw/acpi/acpi-defs.h"
>> +#include "acpi-utils.h"
>> +#include "libqtest.h"
>> +
>> +#define VGID_GUID "324e6eaf-d1d1-4bf6-bf41-b9bb6c91fb87"
>> +#define VMGENID_GUID_OFFSET      40   /* allow space for
>> +                                       * OVMF SDT Header Probe Supressor
>> +                                       */
>> +
>> +static uint32_t vgia;
>> +
>> +typedef struct {
>> +    AcpiTableHeader header;
>> +    gchar name_op;
>> +    gchar vgia[4];
>> +    gchar val_op;
>> +    uint32_t vgia_val;
>> +} QEMU_PACKED VgidTable;
>> +
>> +static uint32_t find_vgia(void)
>> +{
> [...]
> 
> ===
>> +    /* First, find the RSDP */
>> +    for (off = 0xf0000; off < 0x100000; off += 0x10) {
>> +        uint8_t sig[] = "RSD PTR ";
>> +
>> +        for (i = 0; i < sizeof sig - 1; ++i) {
>> +            sig[i] = readb(off + i);
>> +        }
>> +
>> +        if (!memcmp(sig, "RSD PTR ", sizeof sig)) {
>> +            break;
>> +        }
>> +    }
>> +    g_assert_cmphex(off, <, 0x100000);
>> +
>> +    /* Parse the RSDP header so we can find the RSDT */
>> +    ACPI_READ_FIELD(rsdp_table.signature, off);
>> +    ACPI_ASSERT_CMP64(rsdp_table.signature, "RSD PTR ");
>> +
>> +    ACPI_READ_FIELD(rsdp_table.checksum, off);
>> +    ACPI_READ_ARRAY(rsdp_table.oem_id, off);
>> +    ACPI_READ_FIELD(rsdp_table.revision, off);
>> +    ACPI_READ_FIELD(rsdp_table.rsdt_physical_address, off);
>> +
>> +    rsdt = rsdp_table.rsdt_physical_address;
>> +    /* read the header */
>> +    ACPI_READ_TABLE_HEADER(&rsdt_table, rsdt);
>> +    ACPI_ASSERT_CMP(rsdt_table.signature, "RSDT");
>> +
>> +    /* compute the table entries in rsdt */
>> +    tables_nr = (rsdt_table.length - sizeof(AcpiRsdtDescriptorRev1)) /
>> +                sizeof(uint32_t);
>> +    g_assert_cmpint(tables_nr, >, 0);
>> +
>> +    /* get the addresses of the tables pointed by rsdt */
>> +    tables = g_new0(uint32_t, tables_nr);
>> +    ACPI_READ_ARRAY_PTR(tables, tables_nr, rsdt);
> ===
> above is duplicated code from bios-tables-test.c
> please extract it into separate functions and use them in both tests.
> 
Done in v7
>> +    for (i = 0; i < tables_nr; i++) {
>> +        ACPI_READ_TABLE_HEADER(&ssdt_table, tables[i]);
>> +        if (!strncmp((char *)ssdt_table.oem_table_id, "VMGENID", 7)) {
>> +            /* the first entry in the table should be VGIA
>> +             * That's all we need
>> +             */
>> +            ACPI_READ_FIELD(vgid_table.name_op, tables[i]);
>> +            g_assert(vgid_table.name_op == 0x08);  /* name */
>> +            ACPI_READ_ARRAY(vgid_table.vgia, tables[i]);
>> +            g_assert(memcmp(vgid_table.vgia, "VGIA", 4) == 0);
>> +            ACPI_READ_FIELD(vgid_table.val_op, tables[i]);
>> +            g_assert(vgid_table.val_op == 0x0C);  /* dword */
>> +            ACPI_READ_FIELD(vgid_table.vgia_val, tables[i]);
>> +            /* The GUID is written at a fixed offset into the fw_cfg file
>> +             * in order to implement the "OVMF SDT Header probe suppressor"
>> +             * see docs/specs/vmgenid.txt for more details
>> +             */
>> +            return vgid_table.vgia_val + VMGENID_GUID_OFFSET;
>> +        }
>> +    }
>> +    return 0;
>> +}
>> +
>> +static void vmgenid_read_guid(QemuUUID *guid)
>> +{
>> +    int i;
>> +
>> +    if (vgia == 0) {
>> +        vgia = find_vgia();
>> +    }
>> +    g_assert(vgia);
>> +
>> +    /* Read the GUID directly from guest memory */
>> +    for (i = 0; i < 16; i++) {
>> +        guid->data[i] = readb(vgia + i);
>> +    }
>> +    /* The GUID is in little-endian format in the guest, while QEMU
>> +     * uses big-endian.  Swap after reading.
>> +     */
>> +    qemu_uuid_bswap(guid);
>> +}
>> +
>> +static void vmgenid_test(void)
>> +{
>> +    QemuUUID expected, measured;
>> +    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
>> +    vmgenid_read_guid(&measured);
>> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) == 0);
>> +}
>> +
>> +static void vmgenid_set_guid_test(void)
>> +{
>> +    QDict *response;
>> +    gchar *cmd;
>> +    QemuUUID expected, measured;
>> +    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
>> +    /* Change the GUID slightly */
>> +    expected.data[0] += 1;
>> +
>> +    cmd = g_strdup_printf("{ 'execute': 'qom-set', 'arguments': { "
>> +                   "'path': '/machine/peripheral/testvgid', "
>> +                   "'property': 'guid', 'value': '%s' } }",
>> +                   qemu_uuid_unparse_strdup(&expected));
>> +    response = qmp(cmd);
>> +    g_assert(qdict_haskey(response, "return"));
>> +    QDECREF(response);
>> +
>> +    vmgenid_read_guid(&measured);
>> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) == 0);
>> +}
>> +
>> +static void vmgenid_set_guid_auto_test(void)
>> +{
>> +    QDict *response;
>> +    QemuUUID expected, measured;
>> +
>> +    /* Read the initial value */
>> +    vmgenid_read_guid(&expected);
>> +
>> +    /* Setting to 'auto' generates a random GUID */
>> +    response = qmp("{ 'execute': 'qom-set', 'arguments': { "
>> +                   "'path': '/machine/peripheral/testvgid', "
>> +                   "'property': 'guid', 'value': 'auto' } }");
>> +
>> +    g_assert(qdict_haskey(response, "return"));
>> +    QDECREF(response);
>> +
>> +    vmgenid_read_guid(&measured);
>> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) != 0);
>> +}
>> +
>> +int main(int argc, char **argv)
>> +{
>> +    int ret;
>> +    gchar *cmd;
>> +
>> +    g_test_init(&argc, &argv, NULL);
>> +
>> +    cmd = g_strdup_printf("-machine accel=tcg -device vmgenid,id=testvgid,"
>> +                          "guid=%s", VGID_GUID);
>> +    qtest_start(cmd);
>> +    qtest_add_func("/vmgenid/vmgenid", vmgenid_test);
>> +    qtest_add_func("/vmgenid/vmgenid/set-guid", vmgenid_set_guid_test);
> this is probably no necessary as you've dropped dynamic set in v6,
> so if this test passes it's a bug in vmgenid and you should forbid
> setting property after device is realized.
> See how qdev_prop_set_after_realize() is used.
> 
Removed
>> +    qtest_add_func("/vmgenid/vmgenid/set-guid-auto",
>> +                   vmgenid_set_guid_auto_test);
> this should be replaced with this first test but with 'auto' value
> 
> maybe add query-vm-generation-id test
I added code to read from the monitor and compare to the value read from memory.  I hope that’s OK.
> 
>> +    ret = g_test_run();
>> +
>> +    qtest_end();
>> +
>> +    return ret;
>> +}

Patch

diff --git a/tests/Makefile.include b/tests/Makefile.include
index 634394a..ca4b3f7 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -241,6 +241,7 @@  check-qtest-i386-y += tests/usb-hcd-xhci-test$(EXESUF)
 gcov-files-i386-y += hw/usb/hcd-xhci.c
 check-qtest-i386-y += tests/pc-cpu-test$(EXESUF)
 check-qtest-i386-y += tests/q35-test$(EXESUF)
+check-qtest-i386-y += tests/vmgenid-test$(EXESUF)
 gcov-files-i386-y += hw/pci-host/q35.c
 check-qtest-i386-$(CONFIG_VHOST_NET_TEST_i386) += tests/vhost-user-test$(EXESUF)
 ifeq ($(CONFIG_VHOST_NET_TEST_i386),)
@@ -726,6 +727,7 @@  tests/ivshmem-test$(EXESUF): tests/ivshmem-test.o contrib/ivshmem-server/ivshmem
 tests/vhost-user-bridge$(EXESUF): tests/vhost-user-bridge.o contrib/libvhost-user/libvhost-user.o $(test-util-obj-y)
 tests/test-uuid$(EXESUF): tests/test-uuid.o $(test-util-obj-y)
 tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
+tests/vmgenid-test$(EXESUF): tests/vmgenid-test.o
 
 tests/migration/stress$(EXESUF): tests/migration/stress.o
 	$(call quiet-command, $(LINKPROG) -static -O3 $(PTHREAD_LIB) -o $@ $< ,"LINK","$(TARGET_DIR)$@")
diff --git a/tests/vmgenid-test.c b/tests/vmgenid-test.c
new file mode 100644
index 0000000..721ba05
--- /dev/null
+++ b/tests/vmgenid-test.c
@@ -0,0 +1,195 @@ 
+/*
+ * QTest testcase for VM Generation ID
+ *
+ * Copyright (c) 2016 Red Hat, Inc.
+ * Copyright (c) 2017 Skyport Systems
+ *
+ * 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 <glib.h>
+#include <string.h>
+#include <unistd.h>
+#include "qemu/osdep.h"
+#include "qemu/bitmap.h"
+#include "qemu/uuid.h"
+#include "hw/acpi/acpi-defs.h"
+#include "acpi-utils.h"
+#include "libqtest.h"
+
+#define VGID_GUID "324e6eaf-d1d1-4bf6-bf41-b9bb6c91fb87"
+#define VMGENID_GUID_OFFSET      40   /* allow space for
+                                       * OVMF SDT Header Probe Supressor
+                                       */
+
+static uint32_t vgia;
+
+typedef struct {
+    AcpiTableHeader header;
+    gchar name_op;
+    gchar vgia[4];
+    gchar val_op;
+    uint32_t vgia_val;
+} QEMU_PACKED VgidTable;
+
+static uint32_t find_vgia(void)
+{
+    uint32_t off;
+    AcpiRsdpDescriptor rsdp_table;
+    uint32_t rsdt;
+    AcpiRsdtDescriptorRev1 rsdt_table;
+    int tables_nr;
+    uint32_t *tables;
+    AcpiTableHeader ssdt_table;
+    VgidTable vgid_table;
+    int i;
+
+    /* First, find the RSDP */
+    for (off = 0xf0000; off < 0x100000; off += 0x10) {
+        uint8_t sig[] = "RSD PTR ";
+
+        for (i = 0; i < sizeof sig - 1; ++i) {
+            sig[i] = readb(off + i);
+        }
+
+        if (!memcmp(sig, "RSD PTR ", sizeof sig)) {
+            break;
+        }
+    }
+    g_assert_cmphex(off, <, 0x100000);
+
+    /* Parse the RSDP header so we can find the RSDT */
+    ACPI_READ_FIELD(rsdp_table.signature, off);
+    ACPI_ASSERT_CMP64(rsdp_table.signature, "RSD PTR ");
+
+    ACPI_READ_FIELD(rsdp_table.checksum, off);
+    ACPI_READ_ARRAY(rsdp_table.oem_id, off);
+    ACPI_READ_FIELD(rsdp_table.revision, off);
+    ACPI_READ_FIELD(rsdp_table.rsdt_physical_address, off);
+
+    rsdt = rsdp_table.rsdt_physical_address;
+    /* read the header */
+    ACPI_READ_TABLE_HEADER(&rsdt_table, rsdt);
+    ACPI_ASSERT_CMP(rsdt_table.signature, "RSDT");
+
+    /* compute the table entries in rsdt */
+    tables_nr = (rsdt_table.length - sizeof(AcpiRsdtDescriptorRev1)) /
+                sizeof(uint32_t);
+    g_assert_cmpint(tables_nr, >, 0);
+
+    /* get the addresses of the tables pointed by rsdt */
+    tables = g_new0(uint32_t, tables_nr);
+    ACPI_READ_ARRAY_PTR(tables, tables_nr, rsdt);
+
+    for (i = 0; i < tables_nr; i++) {
+        ACPI_READ_TABLE_HEADER(&ssdt_table, tables[i]);
+        if (!strncmp((char *)ssdt_table.oem_table_id, "VMGENID", 7)) {
+            /* the first entry in the table should be VGIA
+             * That's all we need
+             */
+            ACPI_READ_FIELD(vgid_table.name_op, tables[i]);
+            g_assert(vgid_table.name_op == 0x08);  /* name */
+            ACPI_READ_ARRAY(vgid_table.vgia, tables[i]);
+            g_assert(memcmp(vgid_table.vgia, "VGIA", 4) == 0);
+            ACPI_READ_FIELD(vgid_table.val_op, tables[i]);
+            g_assert(vgid_table.val_op == 0x0C);  /* dword */
+            ACPI_READ_FIELD(vgid_table.vgia_val, tables[i]);
+            /* The GUID is written at a fixed offset into the fw_cfg file
+             * in order to implement the "OVMF SDT Header probe suppressor"
+             * see docs/specs/vmgenid.txt for more details
+             */
+            return vgid_table.vgia_val + VMGENID_GUID_OFFSET;
+        }
+    }
+    return 0;
+}
+
+static void vmgenid_read_guid(QemuUUID *guid)
+{
+    int i;
+
+    if (vgia == 0) {
+        vgia = find_vgia();
+    }
+    g_assert(vgia);
+
+    /* Read the GUID directly from guest memory */
+    for (i = 0; i < 16; i++) {
+        guid->data[i] = readb(vgia + i);
+    }
+    /* The GUID is in little-endian format in the guest, while QEMU
+     * uses big-endian.  Swap after reading.
+     */
+    qemu_uuid_bswap(guid);
+}
+
+static void vmgenid_test(void)
+{
+    QemuUUID expected, measured;
+    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
+    vmgenid_read_guid(&measured);
+    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) == 0);
+}
+
+static void vmgenid_set_guid_test(void)
+{
+    QDict *response;
+    gchar *cmd;
+    QemuUUID expected, measured;
+    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
+    /* Change the GUID slightly */
+    expected.data[0] += 1;
+
+    cmd = g_strdup_printf("{ 'execute': 'qom-set', 'arguments': { "
+                   "'path': '/machine/peripheral/testvgid', "
+                   "'property': 'guid', 'value': '%s' } }",
+                   qemu_uuid_unparse_strdup(&expected));
+    response = qmp(cmd);
+    g_assert(qdict_haskey(response, "return"));
+    QDECREF(response);
+
+    vmgenid_read_guid(&measured);
+    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) == 0);
+}
+
+static void vmgenid_set_guid_auto_test(void)
+{
+    QDict *response;
+    QemuUUID expected, measured;
+
+    /* Read the initial value */
+    vmgenid_read_guid(&expected);
+
+    /* Setting to 'auto' generates a random GUID */
+    response = qmp("{ 'execute': 'qom-set', 'arguments': { "
+                   "'path': '/machine/peripheral/testvgid', "
+                   "'property': 'guid', 'value': 'auto' } }");
+
+    g_assert(qdict_haskey(response, "return"));
+    QDECREF(response);
+
+    vmgenid_read_guid(&measured);
+    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data)) != 0);
+}
+
+int main(int argc, char **argv)
+{
+    int ret;
+    gchar *cmd;
+
+    g_test_init(&argc, &argv, NULL);
+
+    cmd = g_strdup_printf("-machine accel=tcg -device vmgenid,id=testvgid,"
+                          "guid=%s", VGID_GUID);
+    qtest_start(cmd);
+    qtest_add_func("/vmgenid/vmgenid", vmgenid_test);
+    qtest_add_func("/vmgenid/vmgenid/set-guid", vmgenid_set_guid_test);
+    qtest_add_func("/vmgenid/vmgenid/set-guid-auto",
+                   vmgenid_set_guid_auto_test);
+    ret = g_test_run();
+
+    qtest_end();
+
+    return ret;
+}