[PATCH v5 4/7] x86/sev, crypto/ccp: Move SNP init to ccp driver

From: Tycho Andersen

Date: Thu Mar 26 2026 - 12:20:05 EST


From: "Tycho Andersen (AMD)" <tycho@xxxxxxxxxx>

Use the new snp_prepare() to initialize SNP from the ccp driver instead of
at boot time. This means that SNP is not enabled unless it is really going
to be used (i.e. kvm_amd loads the ccp driver automatically).

Signed-off-by: Tycho Andersen (AMD) <tycho@xxxxxxxxxx>
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
---
arch/x86/virt/svm/sev.c | 2 --
drivers/crypto/ccp/sev-dev.c | 2 ++
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/virt/svm/sev.c b/arch/x86/virt/svm/sev.c
index 3b2273dca196..423fe77cc70f 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -562,8 +562,6 @@ int __init snp_rmptable_init(void)
if (!setup_rmptable())
return -ENOSYS;

- snp_prepare();
-
/*
* Setting crash_kexec_post_notifiers to 'true' to ensure that SNP panic
* notifier is invoked to do SNP IOMMU shutdown before kdump.
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index aebf4dad545e..4915b0125e8d 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1373,6 +1373,8 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
return -EOPNOTSUPP;
}

+ snp_prepare();
+
/* SNP_INIT requires MSR_VM_HSAVE_PA to be cleared on all CPUs. */
on_each_cpu(snp_set_hsave_pa, NULL, 1);

--
2.53.0