2 commits

Author	SHA1	Message	Date
Ankit Agrawal	0a5b5acdf2	hw/acpi: Implement the SRAT GI affinity structure ... ACPI spec provides a scheme to associate "Generic Initiators" [1] (e.g. heterogeneous processors and accelerators, GPUs, and I/O devices with integrated compute or DMA engines GPUs) with Proximity Domains. This is achieved using Generic Initiator Affinity Structure in SRAT. During bootup, Linux kernel parse the ACPI SRAT to determine the PXM ids and create a NUMA node for each unique PXM ID encountered. Qemu currently do not implement these structures while building SRAT. Add GI structures while building VM ACPI SRAT. The association between device and node are stored using acpi-generic-initiator object. Lookup presence of all such objects and use them to build these structures. The structure needs a PCI device handle [2] that consists of the device BDF. The vfio-pci device corresponding to the acpi-generic-initiator object is located to determine the BDF. [1] ACPI Spec 6.3, Section 5.2.16.6 [2] ACPI Spec 6.3, Table 5.80 Cc: Jonathan Cameron <qemu-devel@nongnu.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Cedric Le Goater <clg@redhat.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Ankit Agrawal <ankita@nvidia.com> Message-Id: <20240308145525.10886-3-ankita@nvidia.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>	2024-03-12 17:56:55 -04:00
Ankit Agrawal	b64b7ed8bb	qom: new object to associate device to NUMA node ... 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 (GI) 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 \ Link: https://www.nvidia.com/en-in/technologies/multi-instance-gpu [1] Cc: Jonathan Cameron <qemu-devel@nongnu.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Markus Armbruster <armbru@redhat.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Ankit Agrawal <ankita@nvidia.com> Message-Id: <20240308145525.10886-2-ankita@nvidia.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>	2024-03-12 17:56:55 -04:00