cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

xen-backend.c (3935B)

      1/*
      2 * Copyright (c) 2018  Citrix Systems Inc.
      3 *
      4 * This work is licensed under the terms of the GNU GPL, version 2 or later.
      5 * See the COPYING file in the top-level directory.
      6 */
      7
      8#include "qemu/osdep.h"
      9#include "qemu/error-report.h"
     10#include "qapi/error.h"
     11#include "hw/xen/xen-backend.h"
     12#include "hw/xen/xen-bus.h"
     13
     14typedef struct XenBackendImpl {
     15    const char *type;
     16    XenBackendDeviceCreate create;
     17    XenBackendDeviceDestroy destroy;
     18} XenBackendImpl;
     19
     20struct XenBackendInstance {
     21    QLIST_ENTRY(XenBackendInstance) entry;
     22    const XenBackendImpl *impl;
     23    XenBus *xenbus;
     24    char *name;
     25    XenDevice *xendev;
     26};
     27
     28static GHashTable *xen_backend_table_get(void)
     29{
     30    static GHashTable *table;
     31
     32    if (table == NULL) {
     33        table = g_hash_table_new(g_str_hash, g_str_equal);
     34    }
     35
     36    return table;
     37}
     38
     39static void xen_backend_table_add(XenBackendImpl *impl)
     40{
     41    g_hash_table_insert(xen_backend_table_get(), (void *)impl->type, impl);
     42}
     43
     44static const char **xen_backend_table_keys(unsigned int *count)
     45{
     46    return (const char **)g_hash_table_get_keys_as_array(
     47        xen_backend_table_get(), count);
     48}
     49
     50static const XenBackendImpl *xen_backend_table_lookup(const char *type)
     51{
     52    return g_hash_table_lookup(xen_backend_table_get(), type);
     53}
     54
     55void xen_backend_register(const XenBackendInfo *info)
     56{
     57    XenBackendImpl *impl = g_new0(XenBackendImpl, 1);
     58
     59    g_assert(info->type);
     60
     61    if (xen_backend_table_lookup(info->type)) {
     62        error_report("attempt to register duplicate Xen backend type '%s'",
     63                     info->type);
     64        abort();
     65    }
     66
     67    if (!info->create) {
     68        error_report("backend type '%s' has no creator", info->type);
     69        abort();
     70    }
     71
     72    impl->type = info->type;
     73    impl->create = info->create;
     74    impl->destroy = info->destroy;
     75
     76    xen_backend_table_add(impl);
     77}
     78
     79const char **xen_backend_get_types(unsigned int *count)
     80{
     81    return xen_backend_table_keys(count);
     82}
     83
     84static QLIST_HEAD(, XenBackendInstance) backend_list;
     85
     86static void xen_backend_list_add(XenBackendInstance *backend)
     87{
     88    QLIST_INSERT_HEAD(&backend_list, backend, entry);
     89}
     90
     91static XenBackendInstance *xen_backend_list_find(XenDevice *xendev)
     92{
     93    XenBackendInstance *backend;
     94
     95    QLIST_FOREACH(backend, &backend_list, entry) {
     96        if (backend->xendev == xendev) {
     97            return backend;
     98        }
     99    }
    100
    101    return NULL;
    102}
    103
    104static void xen_backend_list_remove(XenBackendInstance *backend)
    105{
    106    QLIST_REMOVE(backend, entry);
    107}
    108
    109void xen_backend_device_create(XenBus *xenbus, const char *type,
    110                               const char *name, QDict *opts, Error **errp)
    111{
    112    ERRP_GUARD();
    113    const XenBackendImpl *impl = xen_backend_table_lookup(type);
    114    XenBackendInstance *backend;
    115
    116    if (!impl) {
    117        return;
    118    }
    119
    120    backend = g_new0(XenBackendInstance, 1);
    121    backend->xenbus = xenbus;
    122    backend->name = g_strdup(name);
    123
    124    impl->create(backend, opts, errp);
    125    if (*errp) {
    126        g_free(backend->name);
    127        g_free(backend);
    128        return;
    129    }
    130
    131    backend->impl = impl;
    132    xen_backend_list_add(backend);
    133}
    134
    135XenBus *xen_backend_get_bus(XenBackendInstance *backend)
    136{
    137    return backend->xenbus;
    138}
    139
    140const char *xen_backend_get_name(XenBackendInstance *backend)
    141{
    142    return backend->name;
    143}
    144
    145void xen_backend_set_device(XenBackendInstance *backend,
    146                            XenDevice *xendev)
    147{
    148    g_assert(!backend->xendev);
    149    backend->xendev = xendev;
    150}
    151
    152XenDevice *xen_backend_get_device(XenBackendInstance *backend)
    153{
    154    return backend->xendev;
    155}
    156
    157
    158bool xen_backend_try_device_destroy(XenDevice *xendev, Error **errp)
    159{
    160    XenBackendInstance *backend = xen_backend_list_find(xendev);
    161    const XenBackendImpl *impl;
    162
    163    if (!backend) {
    164        return false;
    165    }
    166
    167    impl = backend->impl;
    168    impl->destroy(backend, errp);
    169
    170    xen_backend_list_remove(backend);
    171    g_free(backend->name);
    172    g_free(backend);
    173
    174    return true;
    175}