1 files changed, 143 insertions, 0 deletions
diff --git a/hw/acpi/viot.c b/hw/acpi/viot.c
new file mode 100644
index 00000000..4e0bf690
--- /dev/null
+++ b/hw/acpi/viot.c
@@ -0,0 +1,143 @@
+/*
+ * ACPI Virtual I/O Translation table implementation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include "qemu/osdep.h"
+#include "hw/acpi/acpi.h"
+#include "hw/acpi/aml-build.h"
+#include "hw/acpi/viot.h"
+#include "hw/pci/pci.h"
+#include "hw/pci/pci_host.h"
+
+struct viot_pci_host_range {
+    int min_bus;
+    int max_bus;
+};
+
+static void build_pci_host_range(GArray *table_data, int min_bus, int max_bus,
+                                 uint16_t output_node)
+{
+    /* Type */
+    build_append_int_noprefix(table_data, 1 /* PCI range */, 1);
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 1);
+    /* Length */
+    build_append_int_noprefix(table_data, 24, 2);
+    /* Endpoint start */
+    build_append_int_noprefix(table_data, PCI_BUILD_BDF(min_bus, 0), 4);
+    /* PCI Segment start */
+    build_append_int_noprefix(table_data, 0, 2);
+    /* PCI Segment end */
+    build_append_int_noprefix(table_data, 0, 2);
+    /* PCI BDF start */
+    build_append_int_noprefix(table_data, PCI_BUILD_BDF(min_bus, 0), 2);
+    /* PCI BDF end */
+    build_append_int_noprefix(table_data, PCI_BUILD_BDF(max_bus, 0xff), 2);
+    /* Output node */
+    build_append_int_noprefix(table_data, output_node, 2);
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 6);
+}
+
+/* Build PCI range for a given PCI host bridge */
+static int enumerate_pci_host_bridges(Object *obj, void *opaque)
+{
+    GArray *pci_host_ranges = opaque;
+
+    if (object_dynamic_cast(obj, TYPE_PCI_HOST_BRIDGE)) {
+        PCIBus *bus = PCI_HOST_BRIDGE(obj)->bus;
+
+        if (bus && !pci_bus_bypass_iommu(bus)) {
+            int min_bus, max_bus;
+
+            pci_bus_range(bus, &min_bus, &max_bus);
+
+            const struct viot_pci_host_range pci_host_range = {
+                .min_bus = min_bus,
+                .max_bus = max_bus,
+            };
+            g_array_append_val(pci_host_ranges, pci_host_range);
+        }
+    }
+
+    return 0;
+}
+
+static gint pci_host_range_compare(gconstpointer a, gconstpointer b)
+{
+    struct viot_pci_host_range *range_a = (struct viot_pci_host_range *)a;
+    struct viot_pci_host_range *range_b = (struct viot_pci_host_range *)b;
+
+    if (range_a->min_bus < range_b->min_bus) {
+        return -1;
+    } else if (range_a->min_bus > range_b->min_bus) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+/*
+ * Generate a VIOT table with one PCI-based virtio-iommu that manages PCI
+ * endpoints.
+ *
+ * Defined in the ACPI Specification (Version TBD)
+ */
+void build_viot(MachineState *ms, GArray *table_data, BIOSLinker *linker,
+                uint16_t virtio_iommu_bdf, const char *oem_id,
+                const char *oem_table_id)
+{
+    /* The virtio-iommu node follows the 48-bytes header */
+    int viommu_off = 48;
+    AcpiTable table = { .sig = "VIOT", .rev = 0,
+                        .oem_id = oem_id, .oem_table_id = oem_table_id };
+    GArray *pci_host_ranges =  g_array_new(false, true,
+                                           sizeof(struct viot_pci_host_range));
+    struct viot_pci_host_range *pci_host_range;
+    int i;
+
+    /* Build the list of PCI ranges that this viommu manages */
+    object_child_foreach_recursive(OBJECT(ms), enumerate_pci_host_bridges,
+                                   pci_host_ranges);
+
+    /* Sort the pci host ranges by min_bus */
+    g_array_sort(pci_host_ranges, pci_host_range_compare);
+
+    /* ACPI table header */
+    acpi_table_begin(&table, table_data);
+    /* Node count */
+    build_append_int_noprefix(table_data, pci_host_ranges->len + 1, 2);
+    /* Node offset */
+    build_append_int_noprefix(table_data, viommu_off, 2);
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 8);
+
+    /* Virtio-iommu node */
+    /* Type */
+    build_append_int_noprefix(table_data, 3 /* virtio-pci IOMMU */, 1);
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 1);
+    /* Length */
+    build_append_int_noprefix(table_data, 16, 2);
+    /* PCI Segment */
+    build_append_int_noprefix(table_data, 0, 2);
+    /* PCI BDF number */
+    build_append_int_noprefix(table_data, virtio_iommu_bdf, 2);
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 8);
+
+    /* PCI ranges found above */
+    for (i = 0; i < pci_host_ranges->len; i++) {
+        pci_host_range = &g_array_index(pci_host_ranges,
+                                        struct viot_pci_host_range, i);
+
+        build_pci_host_range(table_data, pci_host_range->min_bus,
+                             pci_host_range->max_bus, viommu_off);
+    }
+
+    g_array_free(pci_host_ranges, true);
+
+    acpi_table_end(linker, &table);
+}
+