[6/7] KVM: SVM: Add support to initialize SEV/SNP functionality in KVM

Commit Message

Ashish Kalra Dec. 9, 2024, 11:26 p.m. UTC

From: Ashish Kalra <[e-mail]>

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

With this patch, KVM will explicitly call into the PSP driver at load time
to initialize SEV/SNP by default but this behavior can be altered with KVM
module parameters to not do SEV/SNP platform initialization at module load
time if required. Additionally SEV/SNP platform shutdown is invoked during
KVM module unload time.

Signed-off-by: Ashish Kalra <[e-mail]>
---
 arch/x86/kvm/svm/sev.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Patch

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 72674b8825c4..ffb5c907c5bb 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2966,6 +2966,7 @@  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;
@@ -3082,6 +3083,13 @@  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 SEV/SNP INIT */
+	init_args.probe = true;
+	sev_platform_init(&init_args);
 }
 
 void sev_hardware_unsetup(void)
@@ -3097,6 +3105,9 @@  void sev_hardware_unsetup(void)
 
 	misc_cg_set_capacity(MISC_CG_RES_SEV, 0);
 	misc_cg_set_capacity(MISC_CG_RES_SEV_ES, 0);
+
+	/* Do SEV/SNP Shutdown */
+	sev_platform_shutdown();
 }
 
 int sev_cpu_init(struct svm_cpu_data *sd)