[PATCH v7 7/8] KVM: SVM: Add support to initialize SEV/SNP functionality in KVM
From: Ashish Kalra
Date: Mon Mar 24 2025 - 17:20:24 EST
From: Ashish Kalra <ashish.kalra@xxxxxxx>
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@xxxxxxxxxx>
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
---
arch/x86/kvm/svm/sev.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 0bc708ee2788..7be4e1647903 100644
--- 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 @@ void __init sev_hardware_setup(void)
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)
--
2.34.1