[PATCH] KVM: fix powerpc build error for !CONFIG_KVM

Fixes these build error when CONFIG_KVM is not defined:

In file included from arch/powerpc/include/asm/kvm_ppc.h:33:0,
                 from arch/powerpc/kernel/setup_64.c:67:
arch/powerpc/include/asm/kvm_book3s.h:65:20: error: field 'pte' has incomplete type
arch/powerpc/include/asm/kvm_book3s.h:69:18: error: field 'vcpu' has incomplete type
arch/powerpc/include/asm/kvm_book3s.h:98:34: error: 'HPTEG_HASH_NUM_PTE' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:99:39: error: 'HPTEG_HASH_NUM_PTE_LONG' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:100:35: error: 'HPTEG_HASH_NUM_VPTE' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:101:40: error: 'HPTEG_HASH_NUM_VPTE_LONG' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:129:4: error: 'struct kvm_run' declared inside parameter list [-Werror]
arch/powerpc/include/asm/kvm_book3s.h:129:4: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]

... and so on ...

This was introduced by commit f445f11eb2cc265dd47da5b2e864df46cd6e5a82
"KVM: allow host header to be included even for !CONFIG_KVM"

Cc: Kevin Hilman <redacted>
Cc: Marcelo Tosatti <redacted>
Signed-off-by: Stephen Rothwell <redacted>
---
 include/linux/kvm_host.h | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Kevin, does this still fix the error that commit
f445f11eb2cc265dd47da5b2e864df46cd6e5a82 was fixing?

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a942863..90ebec0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h

@@ -1,8 +1,6 @@
 #ifndef __KVM_HOST_H
 #define __KVM_HOST_H
 
-#if IS_ENABLED(CONFIG_KVM)
-
 /*
  * This work is licensed under the terms of the GNU GPL, version 2.  See
  * the COPYING file in the top-level directory.

@@ -751,6 +749,7 @@ static inline int kvm_deassign_device(struct kvm *kvm,
 }
 #endif /* CONFIG_IOMMU_API */
 
+#if IS_ENABLED(CONFIG_KVM)
 static inline void __guest_enter(void)
 {
 	/*

@@ -770,6 +769,10 @@ static inline void __guest_exit(void)
 	vtime_account_system(current);
 	current->flags &= ~PF_VCPU;
 }
+#else
+static inline void __guest_enter(void) { return; }
+static inline void __guest_exit(void) { return; }
+#endif /* IS_ENABLED(CONFIG_KVM) */
 
 #ifdef CONFIG_CONTEXT_TRACKING
 extern void guest_enter(void);

@@ -1057,8 +1060,4 @@ static inline bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu)
 }
 
 #endif /* CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT */
-#else
-static inline void __guest_enter(void) { return; }
-static inline void __guest_exit(void) { return; }
-#endif /* IS_ENABLED(CONFIG_KVM) */
 #endif

-- 
1.8.1

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

On Fri, Mar 22, 2013 at 02:35:50PM +1100, Stephen Rothwell wrote:

Fixes these build error when CONFIG_KVM is not defined:

In file included from arch/powerpc/include/asm/kvm_ppc.h:33:0,
                 from arch/powerpc/kernel/setup_64.c:67:
arch/powerpc/include/asm/kvm_book3s.h:65:20: error: field 'pte' has incomplete type
arch/powerpc/include/asm/kvm_book3s.h:69:18: error: field 'vcpu' has incomplete type
arch/powerpc/include/asm/kvm_book3s.h:98:34: error: 'HPTEG_HASH_NUM_PTE' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:99:39: error: 'HPTEG_HASH_NUM_PTE_LONG' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:100:35: error: 'HPTEG_HASH_NUM_VPTE' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:101:40: error: 'HPTEG_HASH_NUM_VPTE_LONG' undeclared here (not in a function)
arch/powerpc/include/asm/kvm_book3s.h:129:4: error: 'struct kvm_run' declared inside parameter list [-Werror]
arch/powerpc/include/asm/kvm_book3s.h:129:4: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]

... and so on ...

This was introduced by commit f445f11eb2cc265dd47da5b2e864df46cd6e5a82
"KVM: allow host header to be included even for !CONFIG_KVM"

This will re-introduce the problem that Kevin tried to fix with his
original patch. The problem is that kernel/context_tracking.c includes
linux/kvm_host.h unconditionally and the later includes asm/kvm_host.h
and this breaks on archs without KVM.

I think the correct solution is to not include linux/kvm_host.h in
kernel/context_tracking.c unconditionally. The patch by Kevin is here:
http://lkml.org/lkml/2013/3/21/745

--
			Gleb.