tests: Add unit tests for the VM Generation ID feature

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>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 203 insertions, 0 deletions

diff --git a/tests/vmgenid-test.c b/tests/vmgenid-test.c
new file mode 100644
index 0000000..e7ba38c
--- /dev/null
+++ b/tests/vmgenid-test.c
@@ -0,0 +1,203 @@
+/*
+ * 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 rsdp_offset;
+    uint32_t guid_offset = 0;
+    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++) {
+        rsdp_offset = acpi_find_rsdp_address();
+        if (rsdp_offset < RSDP_ADDR_INVALID) {
+            break;
+        }
+        g_usleep(RSDP_SLEEP_US);
+    }
+    g_assert_cmphex(rsdp_offset, <, RSDP_ADDR_INVALID);
+
+    acpi_parse_rsdp_table(rsdp_offset, &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
+             */
+            guid_offset = vgid_table.vgia_val + VMGENID_GUID_OFFSET;
+            break;
+        }
+    }
+    g_free(tables);
+    return guid_offset;
+}
+
+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;
+}