From 83e1bdc94f32dcf52dfcd2025acc7a2b9376b1e8 Mon Sep 17 00:00:00 2001 From: Kai Huang Date: Thu, 14 Dec 2023 11:28:25 +1300 Subject: [PATCH] x86/virt/tdx: Make TDX host depend on X86_MCE A build failure was reported that when INTEL_TDX_HOST is enabled but X86_MCE is not, the tdx_dump_mce_info() function fails to link: ld: vmlinux.o: in function `tdx_dump_mce_info': ...: undefined reference to `mce_is_memory_error' ...: undefined reference to `mce_usable_address' The reason is in such configuration, despite there's no caller of tdx_dump_mce_info() it is still built and there's no implementation for the two "mce_*()" functions. Make INTEL_TDX_HOST depend on X86_MCE to fix. It makes sense to enable MCE support for the TDX host anyway. Because the only way that TDX has to report integrity errors is an MCE, and it is not good to silently ignore such MCE. The TDX spec also suggests the host VMM is expected to implement the MCE handler. Note it also makes sense to make INTEL_TDX_HOST select X86_MCE but this generates "recursive dependency detected!" error in the Kconfig. Closes: https://lore.kernel.org/all/20231212214612.GHZXjUpBFa1IwVMTI7@fat_crate.local/T/ Fixes: 70060463cb2b ("x86/mce: Differentiate real hardware #MCs from TDX erratum ones") Reported-by: Arnd Bergmann Signed-off-by: Kai Huang Signed-off-by: Dave Hansen Reviewed-by: Kirill A. Shutemov Link: https://lore.kernel.org/all/20231212214612.GHZXjUpBFa1IwVMTI7@fat_crate.local/T/#m1a109c29324b2bbd0b3b1d45c218012cd3a13be6 Link: https://lore.kernel.org/all/20231213222825.286809-1-kai.huang%40intel.com --- arch/x86/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 01cdb16acff6..92c03cb99b3e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1974,6 +1974,7 @@ config INTEL_TDX_HOST select ARCH_KEEP_MEMBLOCK depends on CONTIG_ALLOC depends on !KEXEC_CORE + depends on X86_MCE help Intel Trust Domain Extensions (TDX) protects guest VMs from malicious host and certain physical attacks. This option enables necessary TDX -- 2.20.1