Re: [Qemu-devel] [PATCH v6 7/7] tests: Add unit tests for the VM Generation ID feature

[Ben Warren]

> On Feb 15, 2017, at 5:13 AM, Igor Mammedov <address@hidden> wrote:
> 
> On Tue, 14 Feb 2017 22:15:49 -0800
> address@hidden <mailto:address@hidden> wrote:
> 
>> From: Ben Warren <address@hidden>
>> 
>> 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 <address@hidden>  and Igor Mammedov <address@hidden>
>> 
>> Signed-off-by: Ben Warren <address@hidden>
>> ---
>> 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;
>> +}

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