2 ms·

I would like to see these backported into RHEL7. They backported the PCID code due to the Spectre / Meltdown vulns.

• amluto 9y ago
  Did RHEL backport full PCID or just the bare minimum for Meltdown?
  • LinuxBender 9y ago
    Full PCID AFAIK. - [x86] kvm: x86: fix RSM when PCID is non-zero (Paolo Bonzini) [1531662 1530711] - [x86] mm/kaiser: use invpcid to flush the two kaiser PCID AISD (Josh Poimboeuf) [1519800 1519801] {CVE-2017-5754} - [x86] mm/kaiser: use two PCID ASIDs optimize the TLB during enter/exit kernel (Josh Poimboeuf) [1519800 1519801] {CVE-2017-5754} - [x86] mm/kaiser: use PCID feature to make user and kernel switches faster (Josh Poimboeuf) [1519800 1519801] {CVE-2017-5754} This was a significant change and I did not see a formal write-up on it from Redhat. Such a write-up may exist by now.
    • bonzini 9y ago
      If you have specific questions on the implementation, I can try to answer them.
  • bonzini 9y ago
    Just the bare minimum. Only two PCIDs are used. There wasn't enough time unfortunately.
    • LinuxBender 9y ago
      Are there any plans to implement more of it?