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By Zayden R., September 7, 2026
Intel's Dynamic PAMT is poised for inclusion in Linux 7.4, promising reduced memory overhead for systems using Trusted Domain Extensions (TDX). Engineers can expect improved memory efficiency on high-end servers.
Intel's Dynamic PAMT feature is on track to be integrated into Linux 7.4, offering significant memory overhead reductions for systems utilizing Trusted Domain Extensions (TDX). This development is of particular interest to engineers working with confidential virtual machines, as TDX inherently requires additional memory to maintain metadata for each physical page it uses. This overhead can reach up to 0.4% of system memory, a non-trivial amount for modern high-end servers boasting terabytes of RAM.
The Dynamic PAMT (DPAMT) feature, now queued in the x86/tdx branch of the tip/tip.git repository, addresses this issue by enabling part of the Physical Address Metadata Table (PAMT) to be allocated dynamically. This change is expected to be merged in the upcoming Linux 7.4 release, where DPAMT will be enabled by default on supported Intel TDX servers.
The enabling commit explains that DPAMT's memory savings are substantial enough to justify its default configuration whenever the TDX module reports support. The trade-off is a minor increase in kernel size by 2KB when TDX is configured in the build, a small price for the efficiency gains. With memory prices still a concern, the ability to free up RAM resources is a welcome improvement.
For engineers managing systems with TDX, this means less wasted memory and potentially better performance for workloads running on these confidential VMs. As the patches are now part of the development cycle, anticipation grows for their official release, bringing tangible benefits to those operating in environments where every bit of RAM counts.