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jovanbulck / sgx-step

A practical attack framework for precise enclave execution control
GNU General Public License v3.0
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Add x2APIC support #72

Open jovanbulck opened 7 months ago

jovanbulck commented 7 months ago

Nowadays SGX-Step requires nox2apic to operate the APIC timer in memory-mapped I/O mode. It may be useful to also have X2APIC support in SGX-Step.

That would require manipulating MSRs instead of MMIO. This is currently not neatly supported in libsgxstep, but if needed one can implement this manually w call gates, eg as follows:

https://github.com/jovanbulck/sgx-step/blob/master/app/apic/irq_entry.S#L44

jovanbulck commented 7 months ago

https://lkml.org/lkml/2022/8/30/1520

On platforms with the IA32_XAPIC_DISABLE_STATUS MSR, if SGX or TDX are enabled the LEGACY_XAPIC_DISABLED will be set by the BIOS. If legacy APIC is required, then it SGX and TDX need to be disabled in the BIOS.