> 2. page may have had an integrity violation or a hardware error > (we can't tell which), and PageHWPoison(page) is true Right. I think the point of avoiding MOVDIR64B to such page is we cannot tell whether it is a hardware error or not. If it is a hardware error, touching it using MOVDIR64B may cause additional #MC which will panic kernel since now the #MC happens in the kernel context.
