AMD HSMP interface for EPYC and Instinct MI300A
Host System Management Port is AMD's out-of-band management channel on EPYC server processors and the Instinct MI300A APU, used to query and tune power limits, boost behaviour, memory bandwidth, and platform telemetry. It is aimed at datacenter and HPC deployments running modern AMD server silicon, with continued additions for the latest EPYC generations.
recommendation
It should stay because this is the Linux side of a current, actively maintained AMD server feature. Fixes were still landing in early 2026 and new telemetry features were added in May 2025, AMD is still selling EPYC 9005-series CPUs and MI300A accelerators that depend on it, and Ubuntu users were requesting backports as recently as 2025. There is no replacement in the kernel.
repository signals
sources
- patch.msgid.link
A driver-specific HSMP fix was still being merged in March 2026, showing active upstream maintenance rather than removal.
- lore.kernel.org
HSMP gained new telemetry/sysfs functionality in May 2025, indicating feature growth and active development.
- kernel.org
Kernel documentation describes HSMP as the Linux interface for AMD EPYC server CPUs and MI300A, with separate ACPI/platform drivers under drivers/platform/x86/amd/hsmp.
- amd.com
AMD EPYC 9005 server CPUs were actively marketed and shipping in/after late 2024, so relevant HSMP-capable server hardware was still sold new in 2025.
- amd.com
AMD still markets MI300A as a server product; this is a current HSMP-supported platform rather than legacy-only hardware.
- bugs.launchpad.net
Ubuntu carried a 2025 request to support/backport AMD HSMP patches, which is evidence of downstream demand and ongoing deployments.
codex reasoning notes (technical)
Real driver, not an early-exit case. `exec_command` on local git history showed substantive HSMP-only commits through 2026-03-23 and exposed two upstream message URLs from commit trailers (patch.msgid.link and lore.kernel.org). `web.search_query` found kernel docs confirming scope (EPYC + MI300A) and AMD product pages showing the hardware family is still sold. Another web hit on Launchpad showed 2025 downstream backport demand. I also ran a lore-targeted web search for removal/deprecation talk and found no removal discussion in the limited search budget. Niche datacenter/server feature, but current and actively maintained, with no natural upstream replacement driver.