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_ranges {
  14     GArray *blob;
  15     size_t count;
  16     uint16_t output_node;
  17 };
  18
  19 /* Build PCI range for a given PCI host bridge */
  20 static int build_pci_range_node(Object *obj, void *opaque)
  21 {
  22     struct viot_pci_ranges *pci_ranges = opaque;
  23     GArray *blob = pci_ranges->blob;
  24
  25     if (object_dynamic_cast(obj, TYPE_PCI_HOST_BRIDGE)) {
  26         PCIBus *bus = PCI_HOST_BRIDGE(obj)->bus;
  27
  28         if (bus && !pci_bus_bypass_iommu(bus)) {
  29             int min_bus, max_bus;
  30
  31             pci_bus_range(bus, &min_bus, &max_bus);
  32
  33             /* Type */
  34             build_append_int_noprefix(blob, 1 /* PCI range */, 1);
  35             /* Reserved */
  36             build_append_int_noprefix(blob, 0, 1);
  37             /* Length */
  38             build_append_int_noprefix(blob, 24, 2);
  39             /* Endpoint start */
  40             build_append_int_noprefix(blob, PCI_BUILD_BDF(min_bus, 0), 4);
  41             /* PCI Segment start */
  42             build_append_int_noprefix(blob, 0, 2);
  43             /* PCI Segment end */
  44             build_append_int_noprefix(blob, 0, 2);
  45             /* PCI BDF start */
  46             build_append_int_noprefix(blob, PCI_BUILD_BDF(min_bus, 0), 2);
  47             /* PCI BDF end */
  48             build_append_int_noprefix(blob, PCI_BUILD_BDF(max_bus, 0xff), 2);
  49             /* Output node */
  50             build_append_int_noprefix(blob, pci_ranges->output_node, 2);
  51             /* Reserved */
  52             build_append_int_noprefix(blob, 0, 6);
  53
  54             pci_ranges->count++;
  55         }
  56     }
  57
  58     return 0;
  59 }
  60
  61 /*
  62  * Generate a VIOT table with one PCI-based virtio-iommu that manages PCI
  63  * endpoints.
  64  *
  65  * Defined in the ACPI Specification (Version TBD)
  66  */
  67 void build_viot(MachineState *ms, GArray *table_data, BIOSLinker *linker,
  68                 uint16_t virtio_iommu_bdf, const char *oem_id,
  69                 const char *oem_table_id)
  70 {
  71     /* The virtio-iommu node follows the 48-bytes header */
  72     int viommu_off = 48;
  73     AcpiTable table = { .sig = "VIOT", .rev = 0,
  74                         .oem_id = oem_id, .oem_table_id = oem_table_id };
  75     struct viot_pci_ranges pci_ranges = {
  76         .output_node = viommu_off,
  77         .blob = g_array_new(false, true /* clear */, 1),
  78     };
  79
  80     /* Build the list of PCI ranges that this viommu manages */
  81     object_child_foreach_recursive(OBJECT(ms), build_pci_range_node,
  82                                    &pci_ranges);
  83
  84     /* ACPI table header */
  85     acpi_table_begin(&table, table_data);
  86     /* Node count */
  87     build_append_int_noprefix(table_data, pci_ranges.count + 1, 2);
  88     /* Node offset */
  89     build_append_int_noprefix(table_data, viommu_off, 2);
  90     /* Reserved */
  91     build_append_int_noprefix(table_data, 0, 8);
  92
  93     /* Virtio-iommu node */
  94     /* Type */
  95     build_append_int_noprefix(table_data, 3 /* virtio-pci IOMMU */, 1);
  96     /* Reserved */
  97     build_append_int_noprefix(table_data, 0, 1);
  98     /* Length */
  99     build_append_int_noprefix(table_data, 16, 2);
 100     /* PCI Segment */
 101     build_append_int_noprefix(table_data, 0, 2);
 102     /* PCI BDF number */
 103     build_append_int_noprefix(table_data, virtio_iommu_bdf, 2);
 104     /* Reserved */
 105     build_append_int_noprefix(table_data, 0, 8);
 106
 107     /* PCI ranges found above */
 108     g_array_append_vals(table_data, pci_ranges.blob->data,
 109                         pci_ranges.blob->len);
 110     g_array_free(pci_ranges.blob, true);
 111
 112     acpi_table_end(linker, &table);
 113 }
 114