qemu

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/*
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 * ACPI Virtual I/O Translation table implementation
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 *
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 * SPDX-License-Identifier: GPL-2.0-or-later
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 */
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#include "qemu/osdep.h"
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#include "hw/acpi/acpi.h"
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#include "hw/acpi/aml-build.h"
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#include "hw/acpi/viot.h"
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#include "hw/pci/pci.h"
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#include "hw/pci/pci_host.h"
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struct viot_pci_host_range {
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    int min_bus;
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    int max_bus;
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};
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static void build_pci_host_range(GArray *table_data, int min_bus, int max_bus,
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                                 uint16_t output_node)
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{
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    /* Type */
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    build_append_int_noprefix(table_data, 1 /* PCI range */, 1);
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    /* Reserved */
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    build_append_int_noprefix(table_data, 0, 1);
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    /* Length */
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    build_append_int_noprefix(table_data, 24, 2);
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    /* Endpoint start */
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    build_append_int_noprefix(table_data, PCI_BUILD_BDF(min_bus, 0), 4);
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    /* PCI Segment start */
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    build_append_int_noprefix(table_data, 0, 2);
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    /* PCI Segment end */
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    build_append_int_noprefix(table_data, 0, 2);
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    /* PCI BDF start */
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    build_append_int_noprefix(table_data, PCI_BUILD_BDF(min_bus, 0), 2);
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    /* PCI BDF end */
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    build_append_int_noprefix(table_data, PCI_BUILD_BDF(max_bus, 0xff), 2);
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    /* Output node */
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    build_append_int_noprefix(table_data, output_node, 2);
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    /* Reserved */
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    build_append_int_noprefix(table_data, 0, 6);
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}
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/* Build PCI range for a given PCI host bridge */
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static int enumerate_pci_host_bridges(Object *obj, void *opaque)
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{
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    GArray *pci_host_ranges = opaque;
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    if (object_dynamic_cast(obj, TYPE_PCI_HOST_BRIDGE)) {
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        PCIBus *bus = PCI_HOST_BRIDGE(obj)->bus;
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        if (bus && !pci_bus_bypass_iommu(bus)) {
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            int min_bus, max_bus;
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            pci_bus_range(bus, &min_bus, &max_bus);
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            const struct viot_pci_host_range pci_host_range = {
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                .min_bus = min_bus,
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                .max_bus = max_bus,
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            };
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            g_array_append_val(pci_host_ranges, pci_host_range);
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        }
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    }
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    return 0;
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}
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static gint pci_host_range_compare(gconstpointer a, gconstpointer b)
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{
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    struct viot_pci_host_range *range_a = (struct viot_pci_host_range *)a;
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    struct viot_pci_host_range *range_b = (struct viot_pci_host_range *)b;
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    if (range_a->min_bus < range_b->min_bus) {
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        return -1;
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    } else if (range_a->min_bus > range_b->min_bus) {
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        return 1;
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    } else {
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        return 0;
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    }
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}
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/*
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 * Generate a VIOT table with one PCI-based virtio-iommu that manages PCI
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 * endpoints.
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 *
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 * Defined in the ACPI Specification (Version TBD)
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 */
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void build_viot(MachineState *ms, GArray *table_data, BIOSLinker *linker,
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                uint16_t virtio_iommu_bdf, const char *oem_id,
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                const char *oem_table_id)
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{
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    /* The virtio-iommu node follows the 48-bytes header */
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    int viommu_off = 48;
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    AcpiTable table = { .sig = "VIOT", .rev = 0,
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                        .oem_id = oem_id, .oem_table_id = oem_table_id };
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    GArray *pci_host_ranges =  g_array_new(false, true,
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                                           sizeof(struct viot_pci_host_range));
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    struct viot_pci_host_range *pci_host_range;
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    int i;
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    /* Build the list of PCI ranges that this viommu manages */
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    object_child_foreach_recursive(OBJECT(ms), enumerate_pci_host_bridges,
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                                   pci_host_ranges);
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    /* Sort the pci host ranges by min_bus */
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    g_array_sort(pci_host_ranges, pci_host_range_compare);
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    /* ACPI table header */
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    acpi_table_begin(&table, table_data);
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    /* Node count */
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    build_append_int_noprefix(table_data, pci_host_ranges->len + 1, 2);
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    /* Node offset */
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    build_append_int_noprefix(table_data, viommu_off, 2);
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    /* Reserved */
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    build_append_int_noprefix(table_data, 0, 8);
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    /* Virtio-iommu node */
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    /* Type */
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    build_append_int_noprefix(table_data, 3 /* virtio-pci IOMMU */, 1);
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    /* Reserved */
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    build_append_int_noprefix(table_data, 0, 1);
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    /* Length */
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    build_append_int_noprefix(table_data, 16, 2);
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    /* PCI Segment */
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    build_append_int_noprefix(table_data, 0, 2);
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    /* PCI BDF number */
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    build_append_int_noprefix(table_data, virtio_iommu_bdf, 2);
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    /* Reserved */
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    build_append_int_noprefix(table_data, 0, 8);
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    /* PCI ranges found above */
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    for (i = 0; i < pci_host_ranges->len; i++) {
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        pci_host_range = &g_array_index(pci_host_ranges,
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                                        struct viot_pci_host_range, i);
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        build_pci_host_range(table_data, pci_host_range->min_bus,
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                             pci_host_range->max_bus, viommu_off);
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    }
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    g_array_free(pci_host_ranges, true);
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    acpi_table_end(linker, &table);
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}
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