[PATCH 06/11] x86/snp, crypto: move SNP init to ccp driver

Tycho Andersen posted 11 patches 8 hours ago
[PATCH 06/11] x86/snp, crypto: move SNP init to ccp driver
Posted by Tycho Andersen 8 hours ago
From: "Tycho Andersen (AMD)" <tycho@kernel.org>

Use the new snp_prepare_for_snp_init() 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@kernel.org>
---
 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 8f50538baf7b..aa784542b32d 100644
--- a/arch/x86/virt/svm/sev.c
+++ b/arch/x86/virt/svm/sev.c
@@ -549,8 +549,6 @@ int __init snp_rmptable_init(void)
 	if (!setup_rmptable())
 		return -ENOSYS;
 
-	snp_prepare_for_snp_init();
-
 	/*
 	 * 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 096f993974d1..5b1a24b11e3e 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1375,6 +1375,8 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
 		return -EOPNOTSUPP;
 	}
 
+	snp_prepare_for_snp_init();
+
 	/* 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
Re: [PATCH 06/11] x86/snp, crypto: move SNP init to ccp driver
Posted by Tom Lendacky 6 hours ago
On 3/2/26 13:13, Tycho Andersen wrote:
> From: "Tycho Andersen (AMD)" <tycho@kernel.org>
> 
> Use the new snp_prepare_for_snp_init() 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@kernel.org>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> ---
>  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 8f50538baf7b..aa784542b32d 100644
> --- a/arch/x86/virt/svm/sev.c
> +++ b/arch/x86/virt/svm/sev.c
> @@ -549,8 +549,6 @@ int __init snp_rmptable_init(void)
>  	if (!setup_rmptable())
>  		return -ENOSYS;
>  
> -	snp_prepare_for_snp_init();
> -
>  	/*
>  	 * 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 096f993974d1..5b1a24b11e3e 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1375,6 +1375,8 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
>  		return -EOPNOTSUPP;
>  	}
>  
> +	snp_prepare_for_snp_init();
> +
>  	/* SNP_INIT requires MSR_VM_HSAVE_PA to be cleared on all CPUs. */
>  	on_each_cpu(snp_set_hsave_pa, NULL, 1);
>