Add a function that generates a Virtual I/O Translation table (VIOT), describing the topology of paravirtual IOMMUs. The table is created if a virtio-iommu device is present. It contains a virtio-iommu node and PCI Range nodes for endpoints managed by the IOMMU. By default, a single node describes all PCI devices. When passing the "default_bus_bypass_iommu" machine option and "bypass_iommu" PXB option, only buses that do not bypass the IOMMU are described by PCI Range nodes. Reviewed-by: Eric Auger <eric.auger@redhat.com> Tested-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Message-Id: <20211026182024.2642038-2-jean-philippe@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
		
			
				
	
	
		
			115 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			115 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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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_ranges {
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    GArray *blob;
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    size_t count;
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    uint16_t output_node;
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};
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/* Build PCI range for a given PCI host bridge */
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static int build_pci_range_node(Object *obj, void *opaque)
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{
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    struct viot_pci_ranges *pci_ranges = opaque;
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    GArray *blob = pci_ranges->blob;
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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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            /* Type */
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            build_append_int_noprefix(blob, 1 /* PCI range */, 1);
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            /* Reserved */
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            build_append_int_noprefix(blob, 0, 1);
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            /* Length */
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            build_append_int_noprefix(blob, 24, 2);
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            /* Endpoint start */
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            build_append_int_noprefix(blob, PCI_BUILD_BDF(min_bus, 0), 4);
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            /* PCI Segment start */
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            build_append_int_noprefix(blob, 0, 2);
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            /* PCI Segment end */
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            build_append_int_noprefix(blob, 0, 2);
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            /* PCI BDF start */
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            build_append_int_noprefix(blob, PCI_BUILD_BDF(min_bus, 0), 2);
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            /* PCI BDF end */
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            build_append_int_noprefix(blob, PCI_BUILD_BDF(max_bus, 0xff), 2);
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            /* Output node */
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            build_append_int_noprefix(blob, pci_ranges->output_node, 2);
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            /* Reserved */
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            build_append_int_noprefix(blob, 0, 6);
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            pci_ranges->count++;
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        }
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    }
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    return 0;
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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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    struct viot_pci_ranges pci_ranges = {
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        .output_node = viommu_off,
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        .blob = g_array_new(false, true /* clear */, 1),
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    };
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    /* Build the list of PCI ranges that this viommu manages */
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    object_child_foreach_recursive(OBJECT(ms), build_pci_range_node,
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                                   &pci_ranges);
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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_ranges.count + 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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    g_array_append_vals(table_data, pci_ranges.blob->data,
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                        pci_ranges.blob->len);
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    g_array_free(pci_ranges.blob, true);
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    acpi_table_end(linker, &table);
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}
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