<ank...@nvidia.com> writes:
> From: Ankit Agrawal <ank...@nvidia.com>
>
> NVIDIA GPU's support MIG (Mult-Instance GPUs) feature [1], which allows
> partitioning of the GPU device resources (including device memory) into
> several (upto 8) isolated instances. Each of the partitioned memory needs
> a dedicated NUMA node to operate. The partitions are not fixed and they
> can be created/deleted at runtime.
>
> Unfortunately Linux OS does not provide a means to dynamically create/destroy
> NUMA nodes and such feature implementation is not expected to be trivial. The
> nodes that OS discovers at the boot time while parsing SRAT remains fixed. So
> we utilize the Generic Initiator Affinity structures that allows association
> between nodes and devices. Multiple GI structures per BDF is possible,
> allowing creation of multiple nodes by exposing unique PXM in each of these
> structures.
>
> Implement the mechanism to build the GI affinity structures as Qemu currently
> does not. Introduce a new acpi-generic-initiator object to allow host admin
> link a device with an associated NUMA node. Qemu maintains this association
> and use this object to build the requisite GI Affinity Structure.
>
> When multiple numa nodes are associated with a device, it is required to
> create those many number of acpi-generic-initiator objects, each representing
> a unique device:node association.
>
> Following is one of a decoded GI affinity structure in VM ACPI SRAT.
> [0C8h 0200 1] Subtable Type : 05 [Generic Initiator Affinity]
> [0C9h 0201 1] Length : 20
>
> [0CAh 0202 1] Reserved1 : 00
> [0CBh 0203 1] Device Handle Type : 01
> [0CCh 0204 4] Proximity Domain : 00000007
> [0D0h 0208 16] Device Handle : 00 00 20 00 00 00 00 00 00 00
> 00
> 00 00 00 00 00
> [0E0h 0224 4] Flags (decoded below) : 00000001
> Enabled : 1
> [0E4h 0228 4] Reserved2 : 00000000
>
> [0E8h 0232 1] Subtable Type : 05 [Generic Initiator Affinity]
> [0E9h 0233 1] Length : 20
>
> An admin can provide a range of acpi-generic-initiator objects, each
> associating a device (by providing the id through pci-dev argument)
> to the desired numa node (using the node argument). Currently, only PCI
> device is supported.
>
> For the grace hopper system, create a range of 8 nodes and associate that
> with the device using the acpi-generic-initiator object. While a configuration
> of less than 8 nodes per device is allowed, such configuration will prevent
> utilization of the feature to the fullest. The following sample creates 8
> nodes per PCI device for a VM with 2 PCI devices and link them to the
> respecitve PCI device using acpi-generic-initiator objects:
>
> -numa node,nodeid=2 -numa node,nodeid=3 -numa node,nodeid=4 \
> -numa node,nodeid=5 -numa node,nodeid=6 -numa node,nodeid=7 \
> -numa node,nodeid=8 -numa node,nodeid=9 \
> -device
> vfio-pci-nohotplug,host=0009:01:00.0,bus=pcie.0,addr=04.0,rombar=0,id=dev0 \
> -object acpi-generic-initiator,id=gi0,pci-dev=dev0,node=2 \
> -object acpi-generic-initiator,id=gi1,pci-dev=dev0,node=3 \
> -object acpi-generic-initiator,id=gi2,pci-dev=dev0,node=4 \
> -object acpi-generic-initiator,id=gi3,pci-dev=dev0,node=5 \
> -object acpi-generic-initiator,id=gi4,pci-dev=dev0,node=6 \
> -object acpi-generic-initiator,id=gi5,pci-dev=dev0,node=7 \
> -object acpi-generic-initiator,id=gi6,pci-dev=dev0,node=8 \
> -object acpi-generic-initiator,id=gi7,pci-dev=dev0,node=9 \
>
> -numa node,nodeid=10 -numa node,nodeid=11 -numa node,nodeid=12 \
> -numa node,nodeid=13 -numa node,nodeid=14 -numa node,nodeid=15 \
> -numa node,nodeid=16 -numa node,nodeid=17 \
> -device
> vfio-pci-nohotplug,host=0009:01:01.0,bus=pcie.0,addr=05.0,rombar=0,id=dev1 \
> -object acpi-generic-initiator,id=gi8,pci-dev=dev1,node=10 \
> -object acpi-generic-initiator,id=gi9,pci-dev=dev1,node=11 \
> -object acpi-generic-initiator,id=gi10,pci-dev=dev1,node=12 \
> -object acpi-generic-initiator,id=gi11,pci-dev=dev1,node=13 \
> -object acpi-generic-initiator,id=gi12,pci-dev=dev1,node=14 \
> -object acpi-generic-initiator,id=gi13,pci-dev=dev1,node=15 \
> -object acpi-generic-initiator,id=gi14,pci-dev=dev1,node=16 \
> -object acpi-generic-initiator,id=gi15,pci-dev=dev1,node=17 \
>
> The performance benefits can be realized by providing the NUMA node distances
> appropriately (through libvirt tags or Qemu params). The admin can get the
> distance among nodes in hardware using `numactl -H`.
>
> [1] https://www.nvidia.com/en-in/technologies/multi-instance-gpu
>
> Signed-off-by: Ankit Agrawal <ank...@nvidia.com>
> ---
> hw/acpi/acpi-generic-initiator.c | 70 ++++++++++++++++++++++++
> hw/acpi/meson.build | 1 +
> include/hw/acpi/acpi-generic-initiator.h | 32 +++++++++++
> qapi/qom.json | 17 ++++++
> 4 files changed, 120 insertions(+)
> create mode 100644 hw/acpi/acpi-generic-initiator.c
> create mode 100644 include/hw/acpi/acpi-generic-initiator.h
>
> diff --git a/hw/acpi/acpi-generic-initiator.c
> b/hw/acpi/acpi-generic-initiator.c
> new file mode 100644
> index 0000000000..1ade2f723f
> --- /dev/null
> +++ b/hw/acpi/acpi-generic-initiator.c
> @@ -0,0 +1,70 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/acpi/acpi-generic-initiator.h"
> +#include "hw/pci/pci_device.h"
> +#include "qapi/error.h"
> +#include "qapi/qapi-builtin-visit.h"
> +#include "qapi/visitor.h"
> +#include "qemu/error-report.h"
> +
> +OBJECT_DEFINE_TYPE_WITH_INTERFACES(AcpiGenericInitiator,
> acpi_generic_initiator,
> + ACPI_GENERIC_INITIATOR, OBJECT,
> + { TYPE_USER_CREATABLE },
> + { NULL })
> +
> +OBJECT_DECLARE_SIMPLE_TYPE(AcpiGenericInitiator, ACPI_GENERIC_INITIATOR)
> +
> +static void acpi_generic_initiator_init(Object *obj)
> +{
> + AcpiGenericInitiator *gi = ACPI_GENERIC_INITIATOR(obj);
> +
> + gi->node = MAX_NODES;
> + gi->pci_dev = NULL;
> +}
> +
> +static void acpi_generic_initiator_finalize(Object *obj)
> +{
> + AcpiGenericInitiator *gi = ACPI_GENERIC_INITIATOR(obj);
> +
> + g_free(gi->pci_dev);
> +}
> +
> +static void acpi_generic_initiator_set_pci_device(Object *obj, const char
> *val,
> + Error **errp)
> +{
> + AcpiGenericInitiator *gi = ACPI_GENERIC_INITIATOR(obj);
> +
> + gi->pci_dev = g_strdup(val);
> +}
> +
> +static void acpi_generic_initiator_set_node(Object *obj, Visitor *v,
> + const char *name, void *opaque,
> + Error **errp)
> +{
> + AcpiGenericInitiator *gi = ACPI_GENERIC_INITIATOR(obj);
> + uint32_t value;
> +
> + if (!visit_type_uint32(v, name, &value, errp)) {
> + return;
> + }
> +
> + if (value >= MAX_NODES) {
> + error_printf("%s: Invalid NUMA node specified\n",
> + TYPE_ACPI_GENERIC_INITIATOR);
> + exit(1);
> + }
> +
> + gi->node = value;
> +}
> +
> +static void acpi_generic_initiator_class_init(ObjectClass *oc, void *data)
> +{
> + object_class_property_add_str(oc, "pci-dev", NULL,
> + acpi_generic_initiator_set_pci_device);
> + object_class_property_add(oc, "node", "int", NULL,
> + acpi_generic_initiator_set_node, NULL, NULL);
> +}
> diff --git a/hw/acpi/meson.build b/hw/acpi/meson.build
> index fc1b952379..2268589519 100644
> --- a/hw/acpi/meson.build
> +++ b/hw/acpi/meson.build
> @@ -1,5 +1,6 @@
> acpi_ss = ss.source_set()
> acpi_ss.add(files(
> + 'acpi-generic-initiator.c',
> 'acpi_interface.c',
> 'aml-build.c',
> 'bios-linker-loader.c',
> diff --git a/include/hw/acpi/acpi-generic-initiator.h
> b/include/hw/acpi/acpi-generic-initiator.h
> new file mode 100644
> index 0000000000..2f183b029a
> --- /dev/null
> +++ b/include/hw/acpi/acpi-generic-initiator.h
> @@ -0,0 +1,32 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES. All rights reserved
> + */
> +
> +#ifndef ACPI_GENERIC_INITIATOR_H
> +#define ACPI_GENERIC_INITIATOR_H
> +
> +#include "hw/mem/pc-dimm.h"
> +#include "hw/acpi/bios-linker-loader.h"
> +#include "hw/acpi/aml-build.h"
> +#include "sysemu/numa.h"
> +#include "qemu/uuid.h"
> +#include "qom/object.h"
> +#include "qom/object_interfaces.h"
> +
> +#define TYPE_ACPI_GENERIC_INITIATOR "acpi-generic-initiator"
> +
> +typedef struct AcpiGenericInitiator {
> + /* private */
> + Object parent;
> +
> + /* public */
> + char *pci_dev;
> + uint16_t node;
> +} AcpiGenericInitiator;
> +
> +typedef struct AcpiGenericInitiatorClass {
> + ObjectClass parent_class;
> +} AcpiGenericInitiatorClass;
> +
> +#endif
> diff --git a/qapi/qom.json b/qapi/qom.json
> index c53ef978ff..7efa0e14f6 100644
> --- a/qapi/qom.json
> +++ b/qapi/qom.json
> @@ -794,6 +794,21 @@
> { 'struct': 'VfioUserServerProperties',
> 'data': { 'socket': 'SocketAddress', 'device': 'str' } }
>
> +##
> +# @AcpiGenericInitiatorProperties:
> +#
> +# Properties for acpi-generic-initiator objects.
> +#
> +# @pci-dev: PCI device ID to be associated with the node
> +#
> +# @node: numa node associated with the PCI device
NUMA
> +#
> +# Since: 9.0
> +##
> +{ 'struct': 'AcpiGenericInitiatorProperties',
> + 'data': { 'pci-dev': 'str',
> + 'node': 'uint32' } }
> +
> ##
> # @RngProperties:
> #
> @@ -911,6 +926,7 @@
> ##
> { 'enum': 'ObjectType',
> 'data': [
> + 'acpi-generic-initiator',
> 'authz-list',
> 'authz-listfile',
> 'authz-pam',
> @@ -981,6 +997,7 @@
> 'id': 'str' },
> 'discriminator': 'qom-type',
> 'data': {
> + 'acpi-generic-initiator': 'AcpiGenericInitiatorProperties',
> 'authz-list': 'AuthZListProperties',
> 'authz-listfile': 'AuthZListFileProperties',
> 'authz-pam': 'AuthZPAMProperties',
Jonathan, you pointed out interface design issues in your review of v2.
Are you fully satisfied with the interface in v3?
