# Mode-Based Execute Control Architecture reference: Feex Mode-Based Execute Control na Intel EPT capability wey dey allow hypervisor separate guest user-mode and supervisor-mode instruction execution permissions. Na virtualization control, no be normal application instruction. ## Wetin you need know Mode-Based Execute Control na Intel EPT capability wey dey allow hypervisor separate guest user-mode and supervisor-mode instruction execution permissions. Na virtualization control, no be normal application instruction. ## How e dey work When di right VM-execution control dey enabled, EPT permission rules dey separate guest execution modes. Dis one dey allow hypervisor apply policies wey treat user and kernel execution differently for di second translation stage. Di hypervisor must detect and configure di controls properly. ## Where e dey useful Virtualization-based protection design fit use separated execute permissions as one building block. Guest OS and host policy still dey determine wetin dem protect and how dem handle faults; di feature alone no dey turn on security product. ## How to check support and enablement Check di VMX capability controls inside SDM and di hypervisor supported capability/status interface. Check EPT and platform configuration separately. Normal application CPUID feature list no fit fully describe hypervisor policy wey dey active. Virtualized deployment get plenty level dem: physical capability, firmware permission, active host hypervisor, exposed guest capability dem and guest OS support. Check di level where di operation actually dey run, including nested virtualization when e apply. ## Wetin di feature no dey guarantee Dis feature no be di same as NX or SMEP, and generic label wey person import no dey establish di exact behavior for AMD equivalent. E no dey prove say virtualization-based security dey enabled or say machine meet every requirement for specific OS feature. ## Compatibility and performance inside real life CPU execution, guest memory translation and device DMA remapping na separate facility dem. Make you no just guess passthrough or isolation from one virtualization field. Use di hypervisor supported diagnostics and exact platform/device requirement dem. ## Practical verification checklist 1. Record di exact processor or platform model plus di application, OS and runtime version dem wey dey involve. Make you keep di exact word dem wey di error or requirement use. 2. Check di manufacturer reference for dat exact model, den inspect di real capability and enabled state inside di environment where di program dey run. 3. Compare every single requirement of di binary or backend wey you choose. Name wey resemble am, alias, or broad technology label no reach. 4. Confirm say di application select di implementation wey dem intend. Use di diagnostics wey dem document and supported fallback if requirement dem no complete. 5. Make only one supported change at a time, den run di same workload again. Keep di original configuration and recovery way ready. ## If dem list di feature but software no fit use am Start from di exact component wey dey fail. Hardware database dey describe capability wey dem record; di operating system or hypervisor fit show different real environment. If illegal-instruction error happen, you still need to check di exact instruction wey cause di fault and di binary build, because corrupt file or anoda instruction wey no dey supported fit give di same kind problem. Install di application, driver or runtime version wey get support for dat exact platform, and use di vendor documented baseline or fallback build if e need am. Software update no fit create instruction wey di processor no get. Firmware and security-policy change dem suppose follow di system manufacturer procedure and recovery plan, no be just any common optimization advice. ## Related feature dem and useful difference dem [Extended Page Tables (EPT)](https://feex.it/wiki/l/pcm/hardware/system/ept/) · [VT-x](https://feex.it/wiki/l/pcm/hardware/system/vt-x/) · [Execute Disable (NX)](https://feex.it/wiki/l/pcm/hardware/system/execute-disable/) · [OS Guard and SMEP](https://feex.it/wiki/l/pcm/hardware/system/os-guard/) ## Sources and scope of dis explanation [Intel 64 and IA-32 Architectures Software Developer's Manual](https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html) Dis reference dem establish architectural behavior and software requirement dem. Dem no dey independently verify every feature value for any linked hardware model page. For model support, use dat page manufacturer evidence and check di active system configuration. Dis article no supply benchmark, certification or independent review date. ## Related Dis entities connect to dis article. Type dey show for every link. [Extended Page Tables (EPT): Architecture reference](https://feex.it/wiki/l/pcm/hardware/system/ept/)[VT-x: Architecture reference](https://feex.it/wiki/l/pcm/hardware/system/vt-x/)[Execute Disable (NX): Architecture reference](https://feex.it/wiki/l/pcm/hardware/system/execute-disable/)[OS Guard and SMEP: Architecture reference](https://feex.it/wiki/l/pcm/hardware/system/os-guard/) ## Sources and verification Editorial ownership: Feex. No independent review date dey recorded. [How we dey do research](https://feex.it/wiki/research/). - [Intel 64 and IA-32 Architectures Software Developer's Manual ](https://www.intel.com/content/www/us/en/developer/articles/technical/intel-sdm.html)· Volume 1 and 2 describe di named instruction family dem and CPUID; Volume 3 describe state, paging, VMX and protection control dem. Architecture documentation no dey prove say particular model support am. ## Dis article make sense to you? Yes or no dey enough. Choose reason if you want, or add short note. Quick facts The short identity of dis page. Specs, sources, and the full story still dey inside the article. --- Source: [Canonical Feex Wiki page](https://feex.it/wiki/l/pcm/hardware/system/mode-based-execute-control/) [Developer guide](https://feex.it/wiki/developers/) | [API policy](https://feex.it/developers/api-policy/) | [Agent guidance](https://feex.it/wiki/llms.txt)