CVE-2019-1125 is open today, or also known as "SWAPGS" loophole, it is a new variant of Spectre V1, affecting Windows and Linux and Intel collaboration (based on mixing information, AMD-- despite the current Linux kernel patch seems to apply only to Intel at least) x86_64 processors.
Microsoft has quietly patched Windows 10 for this vulnerability, and Linux kernel patch has landed Git . Linux distribution vendor kernel updates being related to the introduction of the existing kernel release. CPU need to update microcode.
Fortunately, SWAPGS to take advantage of loopholes in practice seems very difficult, but it is recommended to upgrade to patch the kernel.
Yes, it looks really affect performance .......