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

["Marc-André Lureau" <marcandre.lureau@gmail.com>]

Hi

On Mon, May 29, 2017 at 7:18 PM Ben Warren via Qemu-devel <
qemu-devel@nongnu.org> wrote:

> From: Ben Warren <ben@skyportsystems.com>
>
> The following tests are implemented:
> * test that a GUID passed in by command line is propagated to the guest.
>   Read the GUID from guest memory
> * test that the "auto" argument to the GUID generates a valid GUID, as
>   seen by the guest.
> * test that a GUID passed in can be queried from the monitor
>
>   This patch is loosely based on a previous patch from:
>   Gal Hammer <ghammer@redhat.com>  and Igor Mammedov <imammedo@redhat.com>
>
> Signed-off-by: Ben Warren <ben@skyportsystems.com>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
> ---
>
> Unchanged from v8, simply rebased to current top-of-tree
>
>  tests/Makefile.include |   2 +
>  tests/vmgenid-test.c   | 200
> +++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 202 insertions(+)
>  create mode 100644 tests/vmgenid-test.c
>
> diff --git a/tests/Makefile.include b/tests/Makefile.include
> index 75893838e5..79bf960336 100644
> --- a/tests/Makefile.include
> +++ b/tests/Makefile.include
> @@ -250,6 +250,7 @@ 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 ($(CONFIG_VHOST_NET_TEST_i386),)
> @@ -758,6 +759,7 @@ tests/test-uuid$(EXESUF): tests/test-uuid.o
> $(test-util-obj-y)
>  tests/test-arm-mptimer$(EXESUF): tests/test-arm-mptimer.o
>  tests/test-qapi-util$(EXESUF): tests/test-qapi-util.o $(test-util-obj-y)
>  tests/numa-test$(EXESUF): tests/numa-test.o
> +tests/vmgenid-test$(EXESUF): tests/vmgenid-test.o tests/acpi-utils.o
>
>  tests/migration/stress$(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 0000000000..123beaea13
> --- /dev/null
> +++ b/tests/vmgenid-test.c
> @@ -0,0 +1,200 @@
> +/*
> + * 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
> +                                  */
> +#define RSDP_ADDR_INVALID 0x100000 /* RSDP must be below this address */
> +#define RSDP_SLEEP_US     100000   /* Sleep for 100ms between tries */
> +#define RSDP_TRIES_MAX    100      /* Max total time is 10 seconds */
> +
> +typedef struct {
> +    AcpiTableHeader header;
> +    gchar name_op;
> +    gchar vgia[4];
> +    gchar val_op;
> +    uint32_t vgia_val;
> +} QEMU_PACKED VgidTable;
> +
> +static uint32_t acpi_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;
> +
> +    /* Tables may take a short time to be set up by the guest */
> +    for (i = 0; i < RSDP_TRIES_MAX; i++) {
> +        off = acpi_find_rsdp_address();
> +        if (off < RSDP_ADDR_INVALID) {
> +            break;
> +        }
> +        g_usleep(RSDP_SLEEP_US);
> +    }
> +    g_assert_cmphex(off, <, RSDP_ADDR_INVALID);
> +
> +    acpi_parse_rsdp_table(off, &rsdp_table);
> +
> +    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;
> +        }
>

It leaks tables

Other than that:
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

+    }
> +    return 0;
> +}
> +
> +static void read_guid_from_memory(QemuUUID *guid)
> +{
> +    uint32_t vmgenid_addr;
> +    int i;
> +
> +    vmgenid_addr = acpi_find_vgia();
> +    g_assert(vmgenid_addr);
> +
> +    /* Read the GUID directly from guest memory */
> +    for (i = 0; i < 16; i++) {
> +        guid->data[i] = readb(vmgenid_addr + 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 read_guid_from_monitor(QemuUUID *guid)
> +{
> +    QDict *rsp, *rsp_ret;
> +    const char *guid_str;
> +
> +    rsp = qmp("{ 'execute': 'query-vm-generation-id' }");
> +    if (qdict_haskey(rsp, "return")) {
> +        rsp_ret = qdict_get_qdict(rsp, "return");
> +        g_assert(qdict_haskey(rsp_ret, "guid"));
> +        guid_str = qdict_get_str(rsp_ret, "guid");
> +        g_assert(qemu_uuid_parse(guid_str, guid) == 0);
> +    }
> +    QDECREF(rsp);
> +}
> +
> +static void vmgenid_set_guid_test(void)
> +{
> +    QemuUUID expected, measured;
> +    gchar *cmd;
> +
> +    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
> +
> +    cmd = g_strdup_printf("-machine accel=tcg -device
> vmgenid,id=testvgid,"
> +                          "guid=%s", VGID_GUID);
> +    qtest_start(cmd);
> +
> +    /* Read the GUID from accessing guest memory */
> +    read_guid_from_memory(&measured);
> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data))
> == 0);
> +
> +    qtest_quit(global_qtest);
> +    g_free(cmd);
> +}
> +
> +static void vmgenid_set_guid_auto_test(void)
> +{
> +    const char *cmd;
> +    QemuUUID measured;
> +
> +    cmd = "-machine accel=tcg -device vmgenid,id=testvgid," "guid=auto";
> +    qtest_start(cmd);
> +
> +    read_guid_from_memory(&measured);
> +
> +    /* Just check that the GUID is non-null */
> +    g_assert(!qemu_uuid_is_null(&measured));
> +
> +    qtest_quit(global_qtest);
> +}
> +
> +static void vmgenid_query_monitor_test(void)
> +{
> +    QemuUUID expected, measured;
> +    gchar *cmd;
> +
> +    g_assert(qemu_uuid_parse(VGID_GUID, &expected) == 0);
> +
> +    cmd = g_strdup_printf("-machine accel=tcg -device
> vmgenid,id=testvgid,"
> +                          "guid=%s", VGID_GUID);
> +    qtest_start(cmd);
> +
> +    /* Read the GUID via the monitor */
> +    read_guid_from_monitor(&measured);
> +    g_assert(memcmp(measured.data, expected.data, sizeof(measured.data))
> == 0);
> +
> +    qtest_quit(global_qtest);
> +    g_free(cmd);
> +}
> +
> +int main(int argc, char **argv)
> +{
> +    int ret;
> +
> +    g_test_init(&argc, &argv, NULL);
> +
> +    qtest_add_func("/vmgenid/vmgenid/set-guid",
> +                   vmgenid_set_guid_test);
> +    qtest_add_func("/vmgenid/vmgenid/set-guid-auto",
> +                   vmgenid_set_guid_auto_test);
> +    qtest_add_func("/vmgenid/vmgenid/query-monitor",
> +                   vmgenid_query_monitor_test);
> +    ret = g_test_run();
> +
> +    return ret;
> +}
> --
> 2.11.0 (Apple Git-81)
>
>
> --
Marc-André Lureau