PCID is now a critical performance/security feature on x86

Re:PCID is now a critical performance/security feature on x86 by dannyw on Monday January 08, 2018 @04:20PM (#16100705)

Can PCID (like HyperThreading, full L3 cache, or extra PCI-e slots in the latest i7s and i9s) be enabled with an update that blows those (e)fuses.

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Re:PCID is now a critical performance/security feature on x86 by monocasa on Monday January 08, 2018 @06:02PM (#16101708)

I don't think it's a feature that's binned off. Intel used to bin off virtualization support (which PCID is technically part off), but they added PCID after they stopped binning on virtualization support.

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Re:PCID is now a critical performance/security feature on x86 by loeg on Monday January 08, 2018 @07:26PM (#16102341)

PCID is supported by low end consumer CPUs since 2010 or so. I don't believe it exists in a disabled form on any hardware. (Maybe I'm mistaken.)

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Re:PCID is now a critical performance/security feature on x86 by pgeorgi on Monday January 08, 2018 @04:50PM (#16100985)

efuses typically have a final efuse to be blown in manufacturing to prevent any further modification of the entire block. Otherwise there's way too high a risk of some broken code accidentally changing the configuration.

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