XK0-005 Question #239: Real Exam Question with Answer & Explanation

Question

A systems administrator is receiving errors while trying to install a popular virtualization software. The software specifications state the processor needs to support virtualization with Intel instructions. Additional requirements state the processor must accelerate encryption/decryption and use hyperthreading. Given the following output about the processor: fpu ume depse tsu msr pae mce cx8 apic sep mtrr pae mca cmov pat pse36 cflusm mmx fxsr sse sse2 ht syscall nx rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt aes xsave avx rdrand hypervisor lahf_lm fsgsbase Which of the following is the MOST likely reason for the errors?

Options

• AThe processor supports AMD instructions rather than Intel.
• BThe processor cannot accelerate decryption.
• CThe processor does not support hyperthreading.
• DThe processor is running inside a virtual machine.

Explanation

The provided processor flags indicate support for virtualization and encryption, but the absence of the 'ht' flag suggests the processor does not support hyperthreading, which is a required specification.

Common mistakes.

• A. The presence of flags like aes, avx, and hypervisor is consistent with Intel processor features for virtualization and encryption, not exclusively AMD.
• B. The aes flag in the output indicates that the processor supports AES-NI (Advanced Encryption Standard New Instructions), which accelerates both encryption and decryption operations.
• D. The hypervisor flag in the CPU output indicates the processor is running inside a virtual machine, but the specific requirement for hyperthreading (the ht flag) is a direct capability of the CPU itself, and its absence is a more precise reason for failure based on the listed requirements.

Concept tested. CPU feature flags for virtualization and hyperthreading

Reference. https://www.kernel.org/doc/Documentation/x86/cpu-flags.txt

No community discussion yet for this question.