Re: [PATCH v11 19/20] x86/mce: Improve error log of kernel space TDX #MC due to erratum

From: Xiaoyao Li
Date: Sun Jun 04 2023 - 22:13:41 EST


On 6/4/2023 10:27 PM, Kai Huang wrote:
== Problem ==

A partial write to a TDX private memory cacheline will silently "poison"
the line. Subsequent reads will consume the poison and generate a
machine check. According to the TDX hardware spec, neither of these
things should have happened.

The expectation is that write to TDX private memory with HKID 0 doesn't poison the cache line. However, a partial write with HKID 0 does poison the cache line. This is the erratum, right?

To add insult to injury, the Linux machine code will present these as a
literal "Hardware error" when they were, in fact, a software-triggered
issue.