AMD says its processors are not vulnerable to the Meltdown bug, but are affected by both variants of the Spectre flaw. AMD says it will make optional microcode updates available to customers and partners for AMD processors starting this week. AMD also said it’s working with the Linux community on implementing a coding technique invented by Google named “return trampoline”” (Retpoline) AMD says an OS-level patch is enough to mitigate this flaw. Microsoft has paused the rollout of Spectre #1 patch for the time being.”
Source: https://www.bleepingcomputer.com/news/hardware/amd-will-release-cpu-microcode-updates-for-spectre-flaw-this-week/