On 2/19/25 14:54, Ashish Kalra wrote:
> From: Ashish Kalra <ashish.kalra@xxxxxxx>
>
> Move platform initialization of SEV/SNP from PSP driver probe time to
s/PSP/CCP/
> 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 PSP driver at load time
s/PSP/CCP/
> to initialize SEV/SNP by default but this behavior can be altered with KVM
s/by default but this/. If required, this/
> module parameters to not do SEV/SNP platform initialization at module load
> time if required. Additionally SEV/SNP platform shutdown is invoked during
s/if required//
s/Additionally/Additionally, a corresponding/
> KVM module unload time.
Some commit message comments and a minor comment below, otherwise:
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> ---
> arch/x86/kvm/svm/sev.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 74525651770a..213d4c15a9da 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 +3060,17 @@ 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;
> +
> + /*
> + * NOTE: Always do SNP INIT regardless of sev_snp_supported
> + * as SNP INIT has to be done to launch legacy SEV/SEV-ES
> + * VMs in case SNP is enabled system-wide.
> + */
But won't this also do an SEV init as long as init_on_probe is true? And
isn't this true for even non-SEV VMs? You have to pause all VMs before
performing SNP INIT. In which case I don't see the point of this
comment. I think you really just want to say:
/*
* Always perform SEV initialization at setup time to avoid
* complications with performing SEV initialization later
* (such as suspending active guests, etc.).
*/
Not that that is much better... but it's more accurate.
Thanks,
Tom
> + init_args.probe = true;
> + sev_platform_init(&init_args);
> }
>
> void sev_hardware_unsetup(void)
> @@ -3074,6 +3086,9 @@ 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 and SNP Shutdown */
> + sev_platform_shutdown();
> }
>
> int sev_cpu_init(struct svm_cpu_data *sd)
