Intel Working On New Hardware-Based Prevention For Spectre-BHI Attacks

While Retbleed was grabbing the headlines last week and attention of kernel developers, an Intel engineer sent out a new patch series adding Linux kernel support for "BHI_DIS" as a new hardware-based mitigation that appears to be coming with future Intel CPUs for better fending off Spectre-BHI (Branch History Injection) that was disclosed back in March. But initial indications are this new hardware-based prevention may be even more costly for performance and is not being enabled by default...