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 <adobriyan@gmail.com>
Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com>
Link: https://patch.msgid.link/20260302212619.710873-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2026-03-02 13:26:19 -08:00
parent 00d572d4cd
commit 55be358e17
3 changed files with 14 additions and 9 deletions

View File

@@ -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

View File

@@ -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

View File

@@ -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