From: Sean Christopherson Date: Mon, 2 Mar 2026 21:26:19 +0000 (-0800) Subject: KVM: x86: Immediately fail the build when possible if required #define is missing X-Git-Tag: v7.1-rc1~118^2~9^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=55be358e17af4aa218f173cd6eb17a0dc423cd70;p=thirdparty%2Fkernel%2Flinux.git KVM: x86: Immediately fail the build when possible if required #define is missing Guard usage of the must-be-defined macros in KVM's multi-include headers with the existing #ifdefs that attempt to alert the developer to a missing macro, and spit out an explicit #error message if a macro is missing, as referencing the missing macro completely defeats the purpose of the #ifdef (the compiler spews a ton of error messages and buries the targeted error message). Suggested-by: Alexey Dobriyan Reviewed-by: Yuan Yao Link: https://patch.msgid.link/20260302212619.710873-1-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index de709fb5bd76a..3776cf5382a26 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -1,8 +1,9 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#if !defined(KVM_X86_OP) || !defined(KVM_X86_OP_OPTIONAL) -BUILD_BUG_ON(1) -#endif - +#if !defined(KVM_X86_OP) || \ + !defined(KVM_X86_OP_OPTIONAL) || \ + !defined(KVM_X86_OP_OPTIONAL_RET0) +#error Missing one or more KVM_X86_OP #defines +#else /* * KVM_X86_OP() and KVM_X86_OP_OPTIONAL() are used to help generate * both DECLARE/DEFINE_STATIC_CALL() invocations and @@ -148,6 +149,7 @@ KVM_X86_OP_OPTIONAL(alloc_apic_backing_page) KVM_X86_OP_OPTIONAL_RET0(gmem_prepare) KVM_X86_OP_OPTIONAL_RET0(gmem_max_mapping_level) KVM_X86_OP_OPTIONAL(gmem_invalidate) +#endif #undef KVM_X86_OP #undef KVM_X86_OP_OPTIONAL diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h index f0aa6996811f9..d5452b3433b7d 100644 --- a/arch/x86/include/asm/kvm-x86-pmu-ops.h +++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h @@ -1,7 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#if !defined(KVM_X86_PMU_OP) || !defined(KVM_X86_PMU_OP_OPTIONAL) -BUILD_BUG_ON(1) -#endif +#if !defined(KVM_X86_PMU_OP) || \ + !defined(KVM_X86_PMU_OP_OPTIONAL) +#error Missing one or more KVM_X86_PMU_OP #defines +#else /* * KVM_X86_PMU_OP() and KVM_X86_PMU_OP_OPTIONAL() are used to help generate @@ -26,6 +27,7 @@ KVM_X86_PMU_OP_OPTIONAL(cleanup) KVM_X86_PMU_OP_OPTIONAL(write_global_ctrl) KVM_X86_PMU_OP(mediated_load) KVM_X86_PMU_OP(mediated_put) +#endif #undef KVM_X86_PMU_OP #undef KVM_X86_PMU_OP_OPTIONAL diff --git a/arch/x86/kvm/vmx/vmcs_shadow_fields.h b/arch/x86/kvm/vmx/vmcs_shadow_fields.h index cad128d1657be..67e821c2be6d5 100644 --- a/arch/x86/kvm/vmx/vmcs_shadow_fields.h +++ b/arch/x86/kvm/vmx/vmcs_shadow_fields.h @@ -1,6 +1,6 @@ #if !defined(SHADOW_FIELD_RO) && !defined(SHADOW_FIELD_RW) -BUILD_BUG_ON(1) -#endif +#error Must #define at least one of SHADOW_FIELD_RO or SHADOW_FIELD_RW +#else #ifndef SHADOW_FIELD_RO #define SHADOW_FIELD_RO(x, y) @@ -74,6 +74,7 @@ SHADOW_FIELD_RW(HOST_GS_BASE, host_gs_base) /* 64-bit */ SHADOW_FIELD_RO(GUEST_PHYSICAL_ADDRESS, guest_physical_address) SHADOW_FIELD_RO(GUEST_PHYSICAL_ADDRESS_HIGH, guest_physical_address) +#endif #undef SHADOW_FIELD_RO #undef SHADOW_FIELD_RW