KVM: SVM: Add support to initialize SEV/SNP functionality in KVM

Move platform initialization of SEV/SNP from CCP driver probe time to
KVM module load time so that KVM can do SEV/SNP platform initialization
explicitly if it actually wants to use SEV/SNP functionality.

Add support for KVM to explicitly call into the CCP driver at load time
to initialize SEV/SNP. If required, this behavior can be altered with KVM
module parameters to not do SEV/SNP platform initialization at module load
time. Additionally, a corresponding SEV/SNP platform shutdown is invoked
during KVM module unload time.

Continue to support SEV deferred initialization as the user may have the
file containing SEV persistent data for SEV INIT_EX available only later
after module load/init.

Suggested-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 0bc708ee278877ffa00a26a21e4c948214b4bc8e..7be4e16479035f3b07b037c44791fea8d2d5a267 100644 (file)
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2933,6 +2933,7 @@ void __init sev_set_cpu_caps(void)
 void __init sev_hardware_setup(void)
 {
        unsigned int eax, ebx, ecx, edx, sev_asid_count, sev_es_asid_count;
+       struct sev_platform_init_args init_args = {0};
        bool sev_snp_supported = false;
        bool sev_es_supported = false;
        bool sev_supported = false;
@@ -3059,6 +3060,15 @@ out:
        sev_supported_vmsa_features = 0;
        if (sev_es_debug_swap_enabled)
                sev_supported_vmsa_features |= SVM_SEV_FEAT_DEBUG_SWAP;
+
+       if (!sev_enabled)
+               return;
+
+       /*
+        * Do both SNP and SEV initialization at KVM module load.
+        */
+       init_args.probe = true;
+       sev_platform_init(&init_args);
 }
 
 void sev_hardware_unsetup(void)
@@ -3074,6 +3084,8 @@ void sev_hardware_unsetup(void)
 
        misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
        misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
+
+       sev_platform_shutdown();
 }
 
 int sev_cpu_init(struct svm_cpu_data *sd)