= Overview =
This patch set introduces support for acpi-generic-initiator devices,
supported by QEMU [1].
The acpi-generic-initiator object is required to support Multi-Instance GPU
(MIG) configurations on NVIDIA GPUs [2]. MIG enables partitioning of GPU
resources into multiple isolated instances, each requiring a dedicated NUMA
node definition.
= Implementation =
This patch set implements the libvirt counterpart to the QEMU feature,
enabling users to configure acpi-generic-initiator objects within libvirt
domain XML.
This includes:
- adding XML syntax to define acpi-generic-initiator objects,
- resolving the acpi-generic-initiator definitions into the proper QEMU
command-line arguments,
- ensuring compatibility with existing NUMA configuration.
= Example =
- Domain XML:
```
...
<cpu mode='host-passthrough' check='none'>
<numa>
<cell id='0' cpus='0-15' memory='8388608' unit='KiB'/>
<cell id='1' memory='0' unit='KiB'/>
<cell id='2' memory='0' unit='KiB'/>
<cell id='3' memory='0' unit='KiB'/>
<cell id='4' memory='0' unit='KiB'/>
<cell id='5' memory='0' unit='KiB'/>
<cell id='6' memory='0' unit='KiB'/>
<cell id='7' memory='0' unit='KiB'/>
<cell id='8' memory='0' unit='KiB'/>
</numa>
</cpu>
...
<devices>
...
<hostdev mode='subsystem' type='pci' managed='no'>
<source>
<address domain='0x0009' bus='0x01' slot='0x00' function='0x0'/>
</source>
<address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
</hostdev>
<acpi-generic-initiator>
<alias name="gi1" />
<pci-dev>hostdev0</pci-dev>
<numa-node>1</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi2" />
<pci-dev>hostdev0</pci-dev>
<numa-node>2</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi3" />
<pci-dev>hostdev0</pci-dev>
<numa-node>3</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi4" />
<pci-dev>hostdev0</pci-dev>
<numa-node>4</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi5" />
<pci-dev>hostdev0</pci-dev>
<numa-node>5</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi6" />
<pci-dev>hostdev0</pci-dev>
<numa-node>6</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi7" />
<pci-dev>hostdev0</pci-dev>
<numa-node>7</numa-node>
</acpi-generic-initiator>
<acpi-generic-initiator>
<alias name="gi8" />
<pci-dev>hostdev0</pci-dev>
<numa-node>8</numa-node>
</acpi-generic-initiator>
</devices>
```
- Generated QEMU command line options:
```
... /usr/bin/qemu-system-aarch64 \
...
-object '{"qom-type":"memory-backend-ram","id":"ram-node0","size":8589934592}' \
-numa node,nodeid=0,cpus=0-15,memdev=ram-node0 \
-numa node,nodeid=1 \
-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 \
...
-device '{"driver":"vfio-pci","host":"0009:01:00.0","id":"hostdev0","bus":"pci.3","addr":"0x0"}'
...
-object acpi-generic-initiator,id=gi1,pci-dev=hostdev0,node=1 \
-object acpi-generic-initiator,id=gi2,pci-dev=hostdev0,node=2 \
-object acpi-generic-initiator,id=gi3,pci-dev=hostdev0,node=3 \
-object acpi-generic-initiator,id=gi4,pci-dev=hostdev0,node=4 \
-object acpi-generic-initiator,id=gi5,pci-dev=hostdev0,node=5 \
-object acpi-generic-initiator,id=gi6,pci-dev=hostdev0,node=6 \
-object acpi-generic-initiator,id=gi7,pci-dev=hostdev0,node=7 \
-object acpi-generic-initiator,id=gi8,pci-dev=hostdev0,node=8
```
= References =
[1] https://lore.kernel.org/all/20231225045603.7654-2-ankita@xxxxxxxxxx/
[2] https://www.nvidia.com/en-in/technologies/multi-instance-gpu/
Andrea Righi (2):
qemu: Allow to define NUMA nodes without memory or CPUs assigned
qemu: Introduce acpi-generic-initiator device
src/ch/ch_domain.c | 1 +
src/conf/domain_conf.c | 153 ++++++++++++++++++++++++++++++++++++++
src/conf/domain_conf.h | 14 ++++
src/conf/domain_postparse.c | 1 +
src/conf/domain_validate.c | 40 ++++++++++
src/conf/numa_conf.c | 3 +
src/conf/schemas/domaincommon.rng | 19 +++++
src/conf/virconftypes.h | 2 +
src/libxl/libxl_driver.c | 6 ++
src/lxc/lxc_driver.c | 6 ++
src/qemu/qemu_command.c | 40 ++++++++--
src/qemu/qemu_domain.c | 2 +
src/qemu/qemu_domain_address.c | 4 +
src/qemu/qemu_driver.c | 3 +
src/qemu/qemu_hotplug.c | 5 ++
src/qemu/qemu_postparse.c | 1 +
src/qemu/qemu_validate.c | 1 +
src/test/test_driver.c | 4 +
18 files changed, 297 insertions(+), 8 deletions(-)
