xen_igd_pt.c (3939B)
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 33 typedef struct { 34 uint8_t offset; 35 uint8_t len; 36 } IGDHostInfo; 37 38 /* Here we just expose minimal host bridge offset subset. */ 39 static 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 49 static 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 80 static 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 98 static 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 } 106 107 static 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 }; 113 114 static void igd_pt_i440fx_register_types(void) 115 { 116 type_register_static(&igd_passthrough_i440fx_info); 117 } 118 119 type_init(igd_pt_i440fx_register_types)