On 18/06/19 15:19, Saar Amar wrote: > I found a bug in sysenter emulation. Patch attached both in plaintext > and as patch file. Do you have a testcase for this? RF is cleared for all instructions here: if (ctxt->rep_prefix && (ctxt->d & String)) ctxt->eflags |= X86_EFLAGS_RF; else ctxt->eflags &= ~X86_EFLAGS_RF; just before em_sysenter is called. Paolo