hw/acpi/viot.c

   1 /*
   2  * ACPI Virtual I/O Translation table implementation
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-or-later
   5  */
   6 #include "qemu/osdep.h"
   7 #include "hw/acpi/acpi.h"
   8 #include "hw/acpi/aml-build.h"
   9 #include "hw/acpi/viot.h"
  10 #include "hw/pci/pci.h"
  11 #include "hw/pci/pci_host.h"
  12
  13 struct viot_pci_host_range {
  14     int min_bus;
  15     int max_bus;
  16 };
  17
  18 static void build_pci_host_range(GArray *table_data, int min_bus, int max_bus,
  19                                  uint16_t output_node)
  20 {
  21     /* Type */
  22     build_append_int_noprefix(table_data, 1 /* PCI range */, 1);
  23     /* Reserved */
  24     build_append_int_noprefix(table_data, 0, 1);
  25     /* Length */
  26     build_append_int_noprefix(table_data, 24, 2);
  27     /* Endpoint start */
  28     build_append_int_noprefix(table_data, PCI_BUILD_BDF(min_bus, 0), 4);
  29     /* PCI Segment start */
  30     build_append_int_noprefix(table_data, 0, 2);
  31     /* PCI Segment end */
  32     build_append_int_noprefix(table_data, 0, 2);
  33     /* PCI BDF start */
  34     build_append_int_noprefix(table_data, PCI_BUILD_BDF(min_bus, 0), 2);
  35     /* PCI BDF end */
  36     build_append_int_noprefix(table_data, PCI_BUILD_BDF(max_bus, 0xff), 2);
  37     /* Output node */
  38     build_append_int_noprefix(table_data, output_node, 2);
  39     /* Reserved */
  40     build_append_int_noprefix(table_data, 0, 6);
  41 }
  42
  43 /* Build PCI range for a given PCI host bridge */
  44 static int enumerate_pci_host_bridges(Object *obj, void *opaque)
  45 {
  46     GArray *pci_host_ranges = opaque;
  47
  48     if (object_dynamic_cast(obj, TYPE_PCI_HOST_BRIDGE)) {
  49         PCIBus *bus = PCI_HOST_BRIDGE(obj)->bus;
  50
  51         if (bus && !pci_bus_bypass_iommu(bus)) {
  52             int min_bus, max_bus;
  53
  54             pci_bus_range(bus, &min_bus, &max_bus);
  55
  56             const struct viot_pci_host_range pci_host_range = {
  57                 .min_bus = min_bus,
  58                 .max_bus = max_bus,
  59             };
  60             g_array_append_val(pci_host_ranges, pci_host_range);
  61         }
  62     }
  63
  64     return 0;
  65 }
  66
  67 static gint pci_host_range_compare(gconstpointer a, gconstpointer b)
  68 {
  69     struct viot_pci_host_range *range_a = (struct viot_pci_host_range *)a;
  70     struct viot_pci_host_range *range_b = (struct viot_pci_host_range *)b;
  71
  72     if (range_a->min_bus < range_b->min_bus) {
  73         return -1;
  74     } else if (range_a->min_bus > range_b->min_bus) {
  75         return 1;
  76     } else {
  77         return 0;
  78     }
  79 }
  80
  81 /*
  82  * Generate a VIOT table with one PCI-based virtio-iommu that manages PCI
  83  * endpoints.
  84  *
  85  * Defined in the ACPI Specification (Version TBD)
  86  */
  87 void build_viot(MachineState *ms, GArray *table_data, BIOSLinker *linker,
  88                 uint16_t virtio_iommu_bdf, const char *oem_id,
  89                 const char *oem_table_id)
  90 {
  91     /* The virtio-iommu node follows the 48-bytes header */
  92     int viommu_off = 48;
  93     AcpiTable table = { .sig = "VIOT", .rev = 0,
  94                         .oem_id = oem_id, .oem_table_id = oem_table_id };
  95     GArray *pci_host_ranges =  g_array_new(false, true,
  96                                            sizeof(struct viot_pci_host_range));
  97     struct viot_pci_host_range *pci_host_range;
  98     int i;
  99
 100     /* Build the list of PCI ranges that this viommu manages */
 101     object_child_foreach_recursive(OBJECT(ms), enumerate_pci_host_bridges,
 102                                    pci_host_ranges);
 103
 104     /* Sort the pci host ranges by min_bus */
 105     g_array_sort(pci_host_ranges, pci_host_range_compare);
 106
 107     /* ACPI table header */
 108     acpi_table_begin(&table, table_data);
 109     /* Node count */
 110     build_append_int_noprefix(table_data, pci_host_ranges->len + 1, 2);
 111     /* Node offset */
 112     build_append_int_noprefix(table_data, viommu_off, 2);
 113     /* Reserved */
 114     build_append_int_noprefix(table_data, 0, 8);
 115
 116     /* Virtio-iommu node */
 117     /* Type */
 118     build_append_int_noprefix(table_data, 3 /* virtio-pci IOMMU */, 1);
 119     /* Reserved */
 120     build_append_int_noprefix(table_data, 0, 1);
 121     /* Length */
 122     build_append_int_noprefix(table_data, 16, 2);
 123     /* PCI Segment */
 124     build_append_int_noprefix(table_data, 0, 2);
 125     /* PCI BDF number */
 126     build_append_int_noprefix(table_data, virtio_iommu_bdf, 2);
 127     /* Reserved */
 128     build_append_int_noprefix(table_data, 0, 8);
 129
 130     /* PCI ranges found above */
 131     for (i = 0; i < pci_host_ranges->len; i++) {
 132         pci_host_range = &g_array_index(pci_host_ranges,
 133                                         struct viot_pci_host_range, i);
 134
 135         build_pci_host_range(table_data, pci_host_range->min_bus,
 136                              pci_host_range->max_bus, viommu_off);
 137     }
 138
 139     g_array_free(pci_host_ranges, true);
 140
 141     acpi_table_end(linker, &table);
 142 }
 143