LXR qemu/hw/pci-host/xen_igd

   1/*
   2 * QEMU Intel IGD Passthrough Host Bridge Emulation
   3 *
   4 * Copyright (c) 2006 Fabrice Bellard
   5 *
   6 * SPDX-License-Identifier: MIT
   7 *
   8 * Permission is hereby granted, free of charge, to any person obtaining a copy
   9 * of this software and associated documentation files (the "Software"), to deal
  10 * in the Software without restriction, including without limitation the rights
  11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 * copies of the Software, and to permit persons to whom the Software is
  13 * furnished to do so, subject to the following conditions:
  14 *
  15 * The above copyright notice and this permission notice shall be included in
  16 * all copies or substantial portions of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24 * THE SOFTWARE.
  25 */
  26
  27#include "qemu/osdep.h"
  28#include "hw/pci/pci.h"
  29#include "hw/pci/pci_host.h"
  30#include "hw/pci-host/i440fx.h"
  31#include "qapi/error.h"
  32
  33typedef struct {
  34    uint8_t offset;
  35    uint8_t len;
  36} IGDHostInfo;
  37
  38/* Here we just expose minimal host bridge offset subset. */
  39static const IGDHostInfo igd_host_bridge_infos[] = {
  40    {PCI_REVISION_ID,         2},
  41    {PCI_SUBSYSTEM_VENDOR_ID, 2},
  42    {PCI_SUBSYSTEM_ID,        2},
  43    {0x50,                    2}, /* SNB: processor graphics control register */
  44    {0x52,                    2}, /* processor graphics control register */
  45    {0xa4,                    4}, /* SNB: graphics base of stolen memory */
  46    {0xa8,                    4}, /* SNB: base of GTT stolen memory */
  47};
  48
  49static void host_pci_config_read(int pos, int len, uint32_t *val, Error **errp)
  50{
  51    int rc, config_fd;
  52    /* Access real host bridge. */
  53    char *path = g_strdup_printf("/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
  54                                 0, 0, 0, 0, "config");
  55
  56    config_fd = open(path, O_RDWR);
  57    if (config_fd < 0) {
  58        error_setg_errno(errp, errno, "Failed to open: %s", path);
  59        goto out;
  60    }
  61
  62    if (lseek(config_fd, pos, SEEK_SET) != pos) {
  63        error_setg_errno(errp, errno, "Failed to seek: %s", path);
  64        goto out_close_fd;
  65    }
  66
  67    do {
  68        rc = read(config_fd, (uint8_t *)val, len);
  69    } while (rc < 0 && (errno == EINTR || errno == EAGAIN));
  70    if (rc != len) {
  71        error_setg_errno(errp, errno, "Failed to read: %s", path);
  72    }
  73
  74 out_close_fd:
  75    close(config_fd);
  76 out:
  77    g_free(path);
  78}
  79
  80static void igd_pt_i440fx_realize(PCIDevice *pci_dev, Error **errp)
  81{
  82    ERRP_GUARD();
  83    uint32_t val = 0;
  84    size_t i;
  85    int pos, len;
  86
  87    for (i = 0; i < ARRAY_SIZE(igd_host_bridge_infos); i++) {
  88        pos = igd_host_bridge_infos[i].offset;
  89        len = igd_host_bridge_infos[i].len;
  90        host_pci_config_read(pos, len, &val, errp);
  91        if (*errp) {
  92            return;
  93        }
  94        pci_default_write_config(pci_dev, pos, val, len);
  95    }
  96}
  97
  98static void igd_passthrough_i440fx_class_init(ObjectClass *klass, void *data)
  99{
 100    DeviceClass *dc = DEVICE_CLASS(klass);
 101    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 102
 103    k->realize = igd_pt_i440fx_realize;
 104    dc->desc = "IGD Passthrough Host bridge";
 105}
 106
 107static const TypeInfo igd_passthrough_i440fx_info = {
 108    .name          = TYPE_IGD_PASSTHROUGH_I440FX_PCI_DEVICE,
 109    .parent        = TYPE_I440FX_PCI_DEVICE,
 110    .instance_size = sizeof(PCII440FXState),
 111    .class_init    = igd_passthrough_i440fx_class_init,
 112};
 113
 114static void igd_pt_i440fx_register_types(void)
 115{
 116    type_register_static(&igd_passthrough_i440fx_info);
 117}
 118
 119type_init(igd_pt_i440fx_register_types)
 120