Hello Sean,
On 3/6/2025 5:11 PM, Ashish Kalra wrote:
> 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)
I am looking for feedback on this patch.
Can we go ahead and merge this patch or are you looking for anything
to be changed specifically for this patch ?
The SNP CipherTextHiding support and SEV firmware hotloading patch-sets
are gated on this patch series, so it will be nice to have some feedback
on moving this patch-set forward.
Thanks,
Ashish
