arch/x86/include/asm/kvm-x86-ops.h | 10 ++++++---- arch/x86/include/asm/kvm-x86-pmu-ops.h | 8 +++++--- arch/x86/kvm/vmx/vmcs_shadow_fields.h | 5 +++-- 3 files changed, 14 insertions(+), 9 deletions(-)
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>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 10 ++++++----
arch/x86/include/asm/kvm-x86-pmu-ops.h | 8 +++++---
arch/x86/kvm/vmx/vmcs_shadow_fields.h | 5 +++--
3 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index de709fb5bd76..3776cf5382a2 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 f0aa6996811f..d5452b3433b7 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 cad128d1657b..67e821c2be6d 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
base-commit: 183bb0ce8c77b0fd1fb25874112bc8751a461e49
--
2.53.0.473.g4a7958ca14-googOn Mon, Mar 02, 2026 at 01:26:19PM +0800, Sean Christopherson wrote: > 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> > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/include/asm/kvm-x86-ops.h | 10 ++++++---- > arch/x86/include/asm/kvm-x86-pmu-ops.h | 8 +++++--- > arch/x86/kvm/vmx/vmcs_shadow_fields.h | 5 +++-- > 3 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h > index de709fb5bd76..3776cf5382a2 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 More clear than the BUILD_BUG_ON(1) to me. Reviewed-by: Yuan Yao <yaoyuan@linux.alibaba.com> > +#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 f0aa6996811f..d5452b3433b7 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 cad128d1657b..67e821c2be6d 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 > > base-commit: 183bb0ce8c77b0fd1fb25874112bc8751a461e49 > -- > 2.53.0.473.g4a7958ca14-goog >
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