cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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virtio-9p.c (8628B)


      1/*
      2 * libqos driver framework
      3 *
      4 * Copyright (c) 2018 Emanuele Giuseppe Esposito <e.emanuelegiuseppe@gmail.com>
      5 *
      6 * This library is free software; you can redistribute it and/or
      7 * modify it under the terms of the GNU Lesser General Public
      8 * License version 2.1 as published by the Free Software Foundation.
      9 *
     10 * This library is distributed in the hope that it will be useful,
     11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13 * Lesser General Public License for more details.
     14 *
     15 * You should have received a copy of the GNU Lesser General Public
     16 * License along with this library; if not, see <http://www.gnu.org/licenses/>
     17 */
     18
     19/*
     20 * Not so fast! You might want to read the 9p developer docs first:
     21 * https://wiki.qemu.org/Documentation/9p
     22 */
     23
     24#include "qemu/osdep.h"
     25#include "libqtest.h"
     26#include "qemu/module.h"
     27#include "standard-headers/linux/virtio_ids.h"
     28#include "virtio-9p.h"
     29#include "qgraph.h"
     30
     31static QGuestAllocator *alloc;
     32static char *local_test_path;
     33
     34/* Concatenates the passed 2 pathes. Returned result must be freed. */
     35static char *concat_path(const char* a, const char* b)
     36{
     37    return g_build_filename(a, b, NULL);
     38}
     39
     40static void init_local_test_path(void)
     41{
     42    char *pwd = g_get_current_dir();
     43    char *template = concat_path(pwd, "qtest-9p-local-XXXXXX");
     44    local_test_path = mkdtemp(template);
     45    if (!local_test_path) {
     46        g_test_message("mkdtemp('%s') failed: %s", template, strerror(errno));
     47    }
     48    g_assert(local_test_path);
     49    g_free(pwd);
     50}
     51
     52void virtio_9p_create_local_test_dir(void)
     53{
     54    struct stat st;
     55    int res;
     56
     57    init_local_test_path();
     58
     59    g_assert(local_test_path != NULL);
     60    res = mkdir(local_test_path, 0777);
     61    if (res < 0) {
     62        g_test_message("mkdir('%s') failed: %s", local_test_path,
     63                       strerror(errno));
     64    }
     65
     66    /* ensure test directory exists now ... */
     67    g_assert(stat(local_test_path, &st) == 0);
     68    /* ... and is actually a directory */
     69    g_assert((st.st_mode & S_IFMT) == S_IFDIR);
     70}
     71
     72void virtio_9p_remove_local_test_dir(void)
     73{
     74    g_assert(local_test_path != NULL);
     75    char *cmd = g_strdup_printf("rm -fr '%s'\n", local_test_path);
     76    int res = system(cmd);
     77    if (res < 0) {
     78        /* ignore error, dummy check to prevent compiler error */
     79    }
     80    g_free(cmd);
     81}
     82
     83char *virtio_9p_test_path(const char *path)
     84{
     85    g_assert(local_test_path);
     86    return concat_path(local_test_path, path);
     87}
     88
     89static void virtio_9p_cleanup(QVirtio9P *interface)
     90{
     91    qvirtqueue_cleanup(interface->vdev->bus, interface->vq, alloc);
     92}
     93
     94static void virtio_9p_setup(QVirtio9P *interface)
     95{
     96    uint64_t features;
     97
     98    features = qvirtio_get_features(interface->vdev);
     99    features &= ~(QVIRTIO_F_BAD_FEATURE | (1ull << VIRTIO_RING_F_EVENT_IDX));
    100    qvirtio_set_features(interface->vdev, features);
    101
    102    interface->vq = qvirtqueue_setup(interface->vdev, alloc, 0);
    103    qvirtio_set_driver_ok(interface->vdev);
    104}
    105
    106/* virtio-9p-device */
    107static void virtio_9p_device_destructor(QOSGraphObject *obj)
    108{
    109    QVirtio9PDevice *v_9p = (QVirtio9PDevice *) obj;
    110    QVirtio9P *v9p = &v_9p->v9p;
    111
    112    virtio_9p_cleanup(v9p);
    113}
    114
    115static void virtio_9p_device_start_hw(QOSGraphObject *obj)
    116{
    117    QVirtio9PDevice *v_9p = (QVirtio9PDevice *) obj;
    118    QVirtio9P *v9p = &v_9p->v9p;
    119
    120    virtio_9p_setup(v9p);
    121}
    122
    123static void *virtio_9p_get_driver(QVirtio9P *v_9p,
    124                                         const char *interface)
    125{
    126    if (!g_strcmp0(interface, "virtio-9p")) {
    127        return v_9p;
    128    }
    129    if (!g_strcmp0(interface, "virtio")) {
    130        return v_9p->vdev;
    131    }
    132
    133    fprintf(stderr, "%s not present in virtio-9p-device\n", interface);
    134    g_assert_not_reached();
    135}
    136
    137static void *virtio_9p_device_get_driver(void *object, const char *interface)
    138{
    139    QVirtio9PDevice *v_9p = object;
    140    return virtio_9p_get_driver(&v_9p->v9p, interface);
    141}
    142
    143static void *virtio_9p_device_create(void *virtio_dev,
    144                                     QGuestAllocator *t_alloc,
    145                                     void *addr)
    146{
    147    QVirtio9PDevice *virtio_device = g_new0(QVirtio9PDevice, 1);
    148    QVirtio9P *interface = &virtio_device->v9p;
    149
    150    interface->vdev = virtio_dev;
    151    alloc = t_alloc;
    152
    153    virtio_device->obj.destructor = virtio_9p_device_destructor;
    154    virtio_device->obj.get_driver = virtio_9p_device_get_driver;
    155    virtio_device->obj.start_hw = virtio_9p_device_start_hw;
    156
    157    return &virtio_device->obj;
    158}
    159
    160/* virtio-9p-pci */
    161static void virtio_9p_pci_destructor(QOSGraphObject *obj)
    162{
    163    QVirtio9PPCI *v9_pci = (QVirtio9PPCI *) obj;
    164    QVirtio9P *interface = &v9_pci->v9p;
    165    QOSGraphObject *pci_vobj =  &v9_pci->pci_vdev.obj;
    166
    167    virtio_9p_cleanup(interface);
    168    qvirtio_pci_destructor(pci_vobj);
    169}
    170
    171static void virtio_9p_pci_start_hw(QOSGraphObject *obj)
    172{
    173    QVirtio9PPCI *v9_pci = (QVirtio9PPCI *) obj;
    174    QVirtio9P *interface = &v9_pci->v9p;
    175    QOSGraphObject *pci_vobj =  &v9_pci->pci_vdev.obj;
    176
    177    qvirtio_pci_start_hw(pci_vobj);
    178    virtio_9p_setup(interface);
    179}
    180
    181static void *virtio_9p_pci_get_driver(void *object, const char *interface)
    182{
    183    QVirtio9PPCI *v_9p = object;
    184    if (!g_strcmp0(interface, "pci-device")) {
    185        return v_9p->pci_vdev.pdev;
    186    }
    187    return virtio_9p_get_driver(&v_9p->v9p, interface);
    188}
    189
    190static void *virtio_9p_pci_create(void *pci_bus, QGuestAllocator *t_alloc,
    191                                  void *addr)
    192{
    193    QVirtio9PPCI *v9_pci = g_new0(QVirtio9PPCI, 1);
    194    QVirtio9P *interface = &v9_pci->v9p;
    195    QOSGraphObject *obj = &v9_pci->pci_vdev.obj;
    196
    197    virtio_pci_init(&v9_pci->pci_vdev, pci_bus, addr);
    198    interface->vdev = &v9_pci->pci_vdev.vdev;
    199    alloc = t_alloc;
    200
    201    g_assert_cmphex(interface->vdev->device_type, ==, VIRTIO_ID_9P);
    202
    203    obj->destructor = virtio_9p_pci_destructor;
    204    obj->start_hw = virtio_9p_pci_start_hw;
    205    obj->get_driver = virtio_9p_pci_get_driver;
    206
    207    return obj;
    208}
    209
    210/**
    211 * Performs regular expression based search and replace on @a haystack.
    212 *
    213 * @param haystack - input string to be parsed, result of replacement is
    214 *                   stored back to @a haystack
    215 * @param pattern - the regular expression pattern for scanning @a haystack
    216 * @param replace_fmt - matches of supplied @a pattern are replaced by this,
    217 *                      if necessary glib printf format can be used to add
    218 *                      variable arguments of this function to this
    219 *                      replacement string
    220 */
    221static void regex_replace(GString *haystack, const char *pattern,
    222                          const char *replace_fmt, ...)
    223{
    224    GRegex *regex;
    225    char *replace, *s;
    226    va_list argp;
    227
    228    va_start(argp, replace_fmt);
    229    replace = g_strdup_vprintf(replace_fmt, argp);
    230    va_end(argp);
    231
    232    regex = g_regex_new(pattern, 0, 0, NULL);
    233    s = g_regex_replace(regex, haystack->str, -1, 0, replace, 0, NULL);
    234    g_string_assign(haystack, s);
    235    g_free(s);
    236    g_regex_unref(regex);
    237    g_free(replace);
    238}
    239
    240void virtio_9p_assign_local_driver(GString *cmd_line, const char *args)
    241{
    242    g_assert_nonnull(local_test_path);
    243
    244    /* replace 'synth' driver by 'local' driver */
    245    regex_replace(cmd_line, "-fsdev synth,", "-fsdev local,");
    246
    247    /* append 'path=...' to '-fsdev ...' group */
    248    regex_replace(cmd_line, "(-fsdev \\w[^ ]*)", "\\1,path='%s'",
    249                  local_test_path);
    250
    251    if (!args) {
    252        return;
    253    }
    254
    255    /* append passed args to '-fsdev ...' group */
    256    regex_replace(cmd_line, "(-fsdev \\w[^ ]*)", "\\1,%s", args);
    257}
    258
    259static void virtio_9p_register_nodes(void)
    260{
    261    const char *str_simple = "fsdev=fsdev0,mount_tag=" MOUNT_TAG;
    262    const char *str_addr = "fsdev=fsdev0,addr=04.0,mount_tag=" MOUNT_TAG;
    263
    264    QPCIAddress addr = {
    265        .devfn = QPCI_DEVFN(4, 0),
    266    };
    267
    268    QOSGraphEdgeOptions opts = {
    269        .before_cmd_line = "-fsdev synth,id=fsdev0",
    270    };
    271
    272    /* virtio-9p-device */
    273    opts.extra_device_opts = str_simple,
    274    qos_node_create_driver("virtio-9p-device", virtio_9p_device_create);
    275    qos_node_consumes("virtio-9p-device", "virtio-bus", &opts);
    276    qos_node_produces("virtio-9p-device", "virtio");
    277    qos_node_produces("virtio-9p-device", "virtio-9p");
    278
    279    /* virtio-9p-pci */
    280    opts.extra_device_opts = str_addr;
    281    add_qpci_address(&opts, &addr);
    282    qos_node_create_driver("virtio-9p-pci", virtio_9p_pci_create);
    283    qos_node_consumes("virtio-9p-pci", "pci-bus", &opts);
    284    qos_node_produces("virtio-9p-pci", "pci-device");
    285    qos_node_produces("virtio-9p-pci", "virtio");
    286    qos_node_produces("virtio-9p-pci", "virtio-9p");
    287
    288}
    289
    290libqos_init(virtio_9p_register_nodes);