qemu

FORK: QEMU emulator
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viot.c (4592B)

      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