Special register read is called "variant 3a" because it allows you to break the privilege level separation like Meltdown and, back in November, Meltdown was cal

Special register read is called "variant 3a" because it allows you to break the privilege level separation like Meltdown and, back in November, Meltdown was called "variant 3". Variant 1 was conditional-branch Spectre (speculative out of bounds accesses) while variant 2 was indirect-branch Spectre (the one that could be used to read host memory from a virtual machine).