Linux 4.18 Gets AMD Patches For Speculative Store Bypass / Spectre V4
The in-development Linux 4.18 kernel will receive the patches for making use of the SPEC_CTRL / VIRT_SPEC MSRs to be provided by future AMD CPUs / firmware updates. The AMD SSBD work done by Konrad Rzeszutek Wilk of Oracle was previously covered here. The AMD SSBD whitepaper can be read here.
The AMD speculative store bypass patches are the only Spectre/Meltdown patches in the x86 space currently queued up for Linux 4.18 via the x86/pti pull request. Granted, we could still see more Spectre/Meltdown improvements land for Linux 4.18 given that this work generally gets accepted outside of the merge window since it's a security issue.
Outside of the x86 space for Spectre there is also Spectre V4 SSBD for ARM64 and finally 32-bit ARM Spectre V1/V2 patches coming with Linux 4.18.