KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP_DD=m

SEV requires access to the AMD cryptographic device APIs, and this
does not work when KVM is builtin and the crypto driver is a module.
Actually the Kconfig conditions for CONFIG_KVM_AMD_SEV try to disable
SEV in that case, but it does not work because the actual crypto
calls are not culled, only sev_hardware_setup() is.

This patch adds two CONFIG_KVM_AMD_SEV checks that gate all the remaining
SEV code; it fixes this particular configuration, and drops 5 KiB of
code when CONFIG_KVM_AMD_SEV=n.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d96092b35936991c839ef5d66a5f58561ebdc149..61ccfb13899ed702d8ab7dc88bdb5489b34bcfeb 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -436,14 +436,18 @@ static inline struct kvm_svm *to_kvm_svm(struct kvm *kvm)
 
 static inline bool svm_sev_enabled(void)
 {
-       return max_sev_asid;
+       return IS_ENABLED(CONFIG_KVM_AMD_SEV) ? max_sev_asid : 0;
 }
 
 static inline bool sev_guest(struct kvm *kvm)
 {
+#ifdef CONFIG_KVM_AMD_SEV
        struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
 
        return sev->active;
+#else
+       return false;
+#endif
 }
 
 static inline int sev_get_asid(struct kvm *kvm)