LXR qemu/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
  13struct viot_pci_host_range {
  14    int min_bus;
  15    int max_bus;
  16};
  17
  18static 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 */
  44static 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
  67static 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 */
  87void 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
 144