On 30/05/2017 17:58, Roman Penyaev wrote: > Indeed, what is left is eventually take it from SS.RPL. J. Ahah! :) But I only suggested that in specific cases. > But jokes aside, with your last patch you seems fixed a race problem > when "CS.RPL is not equal to the CPL in the few instructions between > setting CR0.PE and reloading CS". Yes, exactly. The symptom was a crash (triple fault) when you kept interrupting with "info cpus" a guest that repeatedly went to protected mode and back to real mode. > We will have CPL in var->dpl, and it seems ok. All we need is not > to lose it on the way kernel->userspace->kernel. You're right. So what do you think of the other suggestion (svm.c doesn't clear attributes for unusable registers, QEMU only clears P for unusable registers)? Thanks, Paolo
