From 20c48920583675e67b3824f147726e0fbda735ce Mon Sep 17 00:00:00 2001
From: Sean Christopherson <seanjc@google.com>
Date: Thu, 18 Sep 2025 17:33:00 -0700
Subject: KVM: Export KVM-internal symbols for sub-modules only

Rework the vast majority of KVM's exports to expose symbols only to KVM
submodules, i.e. to x86's kvm-{amd,intel}.ko and PPC's kvm-{pr,hv}.ko.
With few exceptions, KVM's exported APIs are intended (and safe) for KVM-
internal usage only.

Keep kvm_get_kvm(), kvm_get_kvm_safe(), and kvm_put_kvm() as normal
exports, as they are needed by VFIO, and are generally safe for external
usage (though ideally even the get/put APIs would be KVM-internal, and
VFIO would pin a VM by grabbing a reference to its associated file).

Implement a framework in kvm_types.h in anticipation of providing a macro
to restrict KVM-specific kernel exports, i.e. to provide symbol exports
for KVM if and only if KVM is built as one or more modules.

Link: https://lore.kernel.org/r/20250919003303.1355064-3-seanjc@google.com
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/linux/kvm_types.h | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

(limited to 'include/linux')

diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 827ecc0b7e10..490464c205b4 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -3,6 +3,23 @@
 #ifndef __KVM_TYPES_H__
 #define __KVM_TYPES_H__
 
+#include <linux/bits.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <asm/kvm_types.h>
+
+#ifdef KVM_SUB_MODULES
+#define EXPORT_SYMBOL_FOR_KVM_INTERNAL(symbol) \
+	EXPORT_SYMBOL_FOR_MODULES(symbol, __stringify(KVM_SUB_MODULES))
+#else
+#define EXPORT_SYMBOL_FOR_KVM_INTERNAL(symbol)
+#endif
+
+#ifndef __ASSEMBLER__
+
+#include <linux/mutex.h>
+#include <linux/spinlock_types.h>
+
 struct kvm;
 struct kvm_async_pf;
 struct kvm_device_ops;
@@ -19,13 +36,6 @@ struct kvm_memslots;
 
 enum kvm_mr_change;
 
-#include <linux/bits.h>
-#include <linux/mutex.h>
-#include <linux/types.h>
-#include <linux/spinlock_types.h>
-
-#include <asm/kvm_types.h>
-
 /*
  * Address types:
  *
@@ -116,5 +126,6 @@ struct kvm_vcpu_stat_generic {
 };
 
 #define KVM_STATS_NAME_SIZE	48
+#endif /* !__ASSEMBLER__ */
 
 #endif /* __KVM_TYPES_H__ */
-- 
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