qemu/hw/acpi/viot.c
Jean-Philippe Brucker 1f85d74ac5 hw/acpi: Add VIOT table
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>
2021-11-01 18:49:10 -04:00

115 lines
3.6 KiB
C

/*
* 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_ranges {
GArray *blob;
size_t count;
uint16_t output_node;
};
/* Build PCI range for a given PCI host bridge */
static int build_pci_range_node(Object *obj, void *opaque)
{
struct viot_pci_ranges *pci_ranges = opaque;
GArray *blob = pci_ranges->blob;
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);
/* Type */
build_append_int_noprefix(blob, 1 /* PCI range */, 1);
/* Reserved */
build_append_int_noprefix(blob, 0, 1);
/* Length */
build_append_int_noprefix(blob, 24, 2);
/* Endpoint start */
build_append_int_noprefix(blob, PCI_BUILD_BDF(min_bus, 0), 4);
/* PCI Segment start */
build_append_int_noprefix(blob, 0, 2);
/* PCI Segment end */
build_append_int_noprefix(blob, 0, 2);
/* PCI BDF start */
build_append_int_noprefix(blob, PCI_BUILD_BDF(min_bus, 0), 2);
/* PCI BDF end */
build_append_int_noprefix(blob, PCI_BUILD_BDF(max_bus, 0xff), 2);
/* Output node */
build_append_int_noprefix(blob, pci_ranges->output_node, 2);
/* Reserved */
build_append_int_noprefix(blob, 0, 6);
pci_ranges->count++;
}
}
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 };
struct viot_pci_ranges pci_ranges = {
.output_node = viommu_off,
.blob = g_array_new(false, true /* clear */, 1),
};
/* Build the list of PCI ranges that this viommu manages */
object_child_foreach_recursive(OBJECT(ms), build_pci_range_node,
&pci_ranges);
/* ACPI table header */
acpi_table_begin(&table, table_data);
/* Node count */
build_append_int_noprefix(table_data, pci_ranges.count + 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 */
g_array_append_vals(table_data, pci_ranges.blob->data,
pci_ranges.blob->len);
g_array_free(pci_ranges.blob, true);
acpi_table_end(linker, &table);
}