qemu/hw/acpi/viot.c
Mark Cave-Ayland e5f73c8397 hw/acpi/viot: build array of PCI host bridges before generating VIOT ACPI table
Perform the generation of the VIOT ACPI table in 2 separate passes: the first pass
enumerates all of the PCI host bridges and adds the min_bus and max_bus information
to an array.

Once this is done the VIOT table header is generated using the size of the array
to calculate the node count, which means it is no longer necessary to use a
sub-array to hold the PCI host bridge range information along with viommu_off.

Finally the PCI host bridge array is iterated again to add the required entries
to the final VIOT ACPI table.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Ani Sinha <ani@anisinha.ca>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220525173232.31429-4-mark.cave-ayland@ilande.co.uk>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-06-09 19:32:49 -04:00

126 lines
4 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_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;
}
/*
* 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);
/* 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);
}