linux-kernel - [PATCH v3 03/13] KVM: SVM: Move SEV module params/variables to sev.c

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Message-Id: <20210122202144.2756381-4-seanjc@google.com>
Date:   Fri, 22 Jan 2021 12:21:34 -0800
From:   Sean Christopherson <seanjc@...gle.com>
To:     Paolo Bonzini <pbonzini@...hat.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Borislav Petkov <bp@...e.de>,
        Tom Lendacky <thomas.lendacky@....com>,
        Brijesh Singh <brijesh.singh@....com>
Subject: [PATCH v3 03/13] KVM: SVM: Move SEV module params/variables to sev.c

Unconditionally invoke sev_hardware_setup() when configuring SVM and
handle clearing the module params/variable 'sev' and 'sev_es' in
sev_hardware_setup().  This allows making said variables static within
sev.c and reduces the odds of a collision with guest code, e.g. the guest
side of things has already laid claim to 'sev_enabled'.

Reviewed-by: Tom Lendacky <thomas.lendacky@....com>
Reviewed-by: Brijesh Singh <brijesh.singh@....com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/svm/sev.c | 11 +++++++++++
 arch/x86/kvm/svm/svm.c | 15 +--------------
 arch/x86/kvm/svm/svm.h |  2 --
 3 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index ec742dabbd5b..4595f04310e2 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -27,6 +27,14 @@
 
 #define __ex(x) __kvm_handle_fault_on_reboot(x)
 
+/* enable/disable SEV support */
+static int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+module_param(sev, int, 0444);
+
+/* enable/disable SEV-ES support */
+static int sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+module_param(sev_es, int, 0444);
+
 static u8 sev_enc_bit;
 static int sev_flush_asids(void);
 static DECLARE_RWSEM(sev_deactivate_lock);
@@ -1249,6 +1257,9 @@ void __init sev_hardware_setup(void)
 	bool sev_es_supported = false;
 	bool sev_supported = false;
 
+	if (!IS_ENABLED(CONFIG_KVM_AMD_SEV) || !sev)
+		goto out;
+
 	/* Does the CPU support SEV? */
 	if (!boot_cpu_has(X86_FEATURE_SEV))
 		goto out;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 5bd797c7ee60..d223db3a77b0 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -189,14 +189,6 @@ module_param(vls, int, 0444);
 static int vgif = true;
 module_param(vgif, int, 0444);
 
-/* enable/disable SEV support */
-int sev = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
-module_param(sev, int, 0444);
-
-/* enable/disable SEV-ES support */
-int sev_es = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
-module_param(sev_es, int, 0444);
-
 bool __read_mostly dump_invalid_vmcb;
 module_param(dump_invalid_vmcb, bool, 0644);
 
@@ -975,12 +967,7 @@ static __init int svm_hardware_setup(void)
 		kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
 	}
 
-	if (IS_ENABLED(CONFIG_KVM_AMD_SEV) && sev) {
-		sev_hardware_setup();
-	} else {
-		sev = false;
-		sev_es = false;
-	}
+	sev_hardware_setup();
 
 	svm_adjust_mmio_mask();
 
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 0fe874ae5498..8e169835f52a 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -408,8 +408,6 @@ static inline bool gif_set(struct vcpu_svm *svm)
 #define MSR_CR3_LONG_MBZ_MASK			0xfff0000000000000U
 #define MSR_INVALID				0xffffffffU
 
-extern int sev;
-extern int sev_es;
 extern bool dump_invalid_vmcb;
 
 u32 svm_msrpm_offset(u32 msr);
-- 
2.30.0.280.ga3ce27912f-goog