Re: [PATCH v4 6/6] KVM: SVM: Delay legacy platform initialization on SNP

[Tom Lendacky]

On 11/4/24 19:05, Dionna Glaze wrote:
> When no SEV or SEV-ES guests are active, then the firmware can be
> updated while (SEV-SNP) VM guests are active.
> 
> CC: Sean Christopherson <seanjc@xxxxxxxxxx>
> CC: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Borislav Petkov <bp@xxxxxxxxx>
> CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> CC: Ashish Kalra <ashish.kalra@xxxxxxx>
> CC: Tom Lendacky <thomas.lendacky@xxxxxxx>
> CC: John Allen <john.allen@xxxxxxx>
> CC: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> CC: "David S. Miller" <davem@xxxxxxxxxxxxx>
> CC: Michael Roth <michael.roth@xxxxxxx>
> CC: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> CC: Russ Weight <russ.weight@xxxxxxxxx>
> CC: Danilo Krummrich <dakr@xxxxxxxxxx>
> CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> CC: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> CC: Tianfei zhang <tianfei.zhang@xxxxxxxxx>
> CC: Alexey Kardashevskiy <aik@xxxxxxx>
> 
> Co-developed-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> Reviewed-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> Signed-off-by: Dionna Glaze <dionnaglaze@xxxxxxxxxx>
> ---
>  arch/x86/kvm/svm/sev.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index f6e96ec0a5caa..3c2079ba7c76f 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -444,7 +444,7 @@ static int __sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp,
>  	if (ret)
>  		goto e_no_asid;
>  
> -	init_args.probe = false;
> +	init_args.probe = vm_type != KVM_X86_SEV_VM && vm_type != KVM_X86_SEV_ES_VM;

Add a comment above the setting of probe to indicate the intent of doing
this. Otherwise you have to go to the ccp code to understand what is
happening.

Thanks,
Tom

>  	ret = sev_platform_init(&init_args);
>  	if (ret)
>  		goto e_free;