KVM: SVM: Tag sev_supported_vmsa_features as read-only after init

Tag sev_supported_vmsa_features with __ro_after_init as it's configured by
sev_hardware_setup() and never written after initial configuration (and if
it were, that'd be a blatant bug).

Opportunistically relocate the variable out of the module params area now
that sev_es_debug_swap_enabled is gone (which largely motivated its
original location).

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://patch.msgid.link/20260109033101.1005769-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/kvm/svm/sev.c

@@ -53,8 +53,6 @@ module_param_named(sev_es, sev_es_enabled, bool, 0444);
 static bool sev_snp_enabled = true;
 module_param_named(sev_snp, sev_snp_enabled, bool, 0444);
 
-static u64 sev_supported_vmsa_features;
-
 static unsigned int nr_ciphertext_hiding_asids;
 module_param_named(ciphertext_hiding_asids, nr_ciphertext_hiding_asids, uint, 0444);
 
@@ -81,6 +79,8 @@ module_param_named(ciphertext_hiding_asids, nr_ciphertext_hiding_asids, uint, 04
 
 static u64 snp_supported_policy_bits __ro_after_init;
 
+static u64 sev_supported_vmsa_features __ro_after_init;
+
 #define INITIAL_VMSA_GPA 0xFFFFFFFFF000
 
 static u8 sev_enc_bit;