linux-kernel - [PATCH AUTOSEL 4.18 14/27] KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP

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Message-Id: <20181022101924.40531-14-sashal@kernel.org>
Date:   Mon, 22 Oct 2018 06:19:11 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     stable@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.18 14/27] KVM: x86: support CONFIG_KVM_AMD=y with CONFIG_CRYPTO_DEV_CCP_DD=m

From: Paolo Bonzini <pbonzini@...hat.com>

[ Upstream commit 853c110982eaff0d99dace3f66f1ba58b5bfd9d5 ]

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@...ck-us.net>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/kvm/svm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ef772e5634d4..3e59a187fe30 100644
--- 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)
-- 
2.17.1