On Thu, May 03, 2018 at 08:08:39PM +0800, Luwei Kang wrote: > +static void pt_guest_enter(struct vcpu_vmx *vmx) > +{ > + if (pt_mode == PT_MODE_HOST || pt_mode == PT_MODE_HOST_GUEST) > + rdmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl); > + > + if (pt_mode == PT_MODE_HOST_GUEST && > + vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) { > + wrmsrl(MSR_IA32_RTIT_CTL, 0); > + pt_save_msr(&vmx->pt_desc.host, vmx->pt_desc.range_cnt); > + pt_load_msr(&vmx->pt_desc.guest, vmx->pt_desc.range_cnt); > + } > +} > + > +static void pt_guest_exit(struct vcpu_vmx *vmx) > +{ > + if (pt_mode == PT_MODE_HOST_GUEST && > + vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) { > + pt_save_msr(&vmx->pt_desc.guest, vmx->pt_desc.range_cnt); > + pt_load_msr(&vmx->pt_desc.host, vmx->pt_desc.range_cnt); > + } > + > + if (pt_mode == PT_MODE_HOST || pt_mode == PT_MODE_HOST_GUEST) > + wrmsrl(MSR_IA32_RTIT_CTL, vmx->pt_desc.host.ctl); > +} This means that a host PT event won't get the guest traces and won't get any notification as to what'd happened or why. At the minimum we need to send a PARTIAL AUX record at the pt_guest_enter(), when we turn the host tracing off. Regards, -- Alex