x86/tdx: Enable CPU topology enumeration

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TDX 1.0 defines baseline behaviour of TDX guest platform. TDX 1.0
generates a #VE when accessing topology-related CPUID leafs (0xB and
0x1F) and the X2APIC_APICID MSR. The kernel returns all zeros on CPUID
topology. In practice, this means that the kernel can only boot with a
plain topology. Any complications will cause problems.

The ENUM_TOPOLOGY feature allows the VMM to provide topology
information to the guest. Enabling the feature eliminates
topology-related #VEs: the TDX module virtualizes accesses to
the CPUID leafs and the MSR.

Enable ENUM_TOPOLOGY if it is available.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kai Huang <kai.huang@intel.com>
Link: https://lore.kernel.org/all/20241104103803.195705-5-kirill.shutemov%40linux.intel.com

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Kirill A. Shutemov 2024-11-04 12:38:03 +02:00 • committed by Dave Hansen

parent f65aa0ad79

commit 7ae15e2f69

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27

arch/x86/coco/tdx/tdx.c

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2

arch/x86/include/asm/shared/tdx.h

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