= 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,
- adding a new qemu capability flag,
- 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>
...
<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 \
...
-object
'{"qom-type":"acpi-generic-initiator","id":"gi1","pci-dev":"hostdev0","node":1}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi2","pci-dev":"hostdev0","node":2}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi3","pci-dev":"hostdev0","node":3}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi4","pci-dev":"hostdev0","node":4}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi5","pci-dev":"hostdev0","node":5}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi6","pci-dev":"hostdev0","node":6}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi7","pci-dev":"hostdev0","node":7}'
\
-object
'{"qom-type":"acpi-generic-initiator","id":"gi8","pci-dev":"hostdev0","node":8}'
```
= References =
[1] https://lore.kernel.org/all/20231225045603.7654-2-ank...@nvidia.com/
[2] https://www.nvidia.com/en-in/technologies/multi-instance-gpu/
ChangeLog v1 -> v2:
- split parser and driver changes in separate patches
- introduce a new qemu capability flag
- introduce test in qemuxmlconftest
Andrea Righi (6):
schema: Introduce acpi-generic-initiator definition
conf: Introduce acpi-generic-initiator device
qemu: Allow to define NUMA nodes without memory or CPUs assigned
qemu: capabilies: Introduce QEMU_CAPS_ACPI_GENERIC_INITIATOR
qemu: support acpi-generic-initiator
qemu: Add test case for acpi-generic-initiator
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_capabilities.c | 2 +
src/qemu/qemu_capabilities.h | 1 +
src/qemu/qemu_command.c | 48 +++++--
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 +
tests/qemucapabilitiesdata/caps_10.0.0_x86_64.xml | 1 +
tests/qemucapabilitiesdata/caps_9.0.0_x86_64.xml | 1 +
tests/qemucapabilitiesdata/caps_9.1.0_riscv64.xml | 1 +
tests/qemucapabilitiesdata/caps_9.1.0_x86_64.xml | 1 +
tests/qemucapabilitiesdata/caps_9.2.0_x86_64.xml | 1 +
.../acpi-generic-initiator.x86_64-latest.args | 55 ++++++++
.../acpi-generic-initiator.x86_64-latest.xml | 102 ++++++++++++++
tests/qemuxmlconfdata/acpi-generic-initiator.xml | 102 ++++++++++++++
tests/qemuxmlconftest.c | 1 +
29 files changed, 573 insertions(+), 8 deletions(-)
create mode 100644
tests/qemuxmlconfdata/acpi-generic-initiator.x86_64-latest.args
create mode 100644
tests/qemuxmlconfdata/acpi-generic-initiator.x86_64-latest.xml
create mode 100644 tests/qemuxmlconfdata/acpi-generic-initiator.xml
