KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported)

Enable the 'sev' and 'sev_es' module params by default instead of having
them conditioned on CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT.  The extra
Kconfig is pointless as KVM SEV/SEV-ES support is already controlled via
CONFIG_KVM_AMD_SEV, and CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT has the
unfortunate side effect of enabling all the SEV-ES _guest_ code due to
it being dependent on CONFIG_AMD_MEM_ENCRYPT=y.

Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422021125.3417167-10-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/sev.c

@@ -46,11 +46,11 @@
 
 #ifdef CONFIG_KVM_AMD_SEV
 /* enable/disable SEV support */
-static bool sev_enabled = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+static bool sev_enabled = true;
 module_param_named(sev, sev_enabled, bool, 0444);
 
 /* enable/disable SEV-ES support */
-static bool sev_es_enabled = IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT);
+static bool sev_es_enabled = true;
 module_param_named(sev_es, sev_es_enabled, bool, 0444);
 #else
 #define sev_enabled false