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

Dionna Glaze posted 6 patches 2 weeks, 5 days ago
[PATCH v4 6/6] KVM: SVM: Delay legacy platform initialization on SNP
Posted by Dionna Glaze 2 weeks, 5 days ago
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@google.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Dave Hansen <dave.hansen@linux.intel.com>
CC: Ashish Kalra <ashish.kalra@amd.com>
CC: Tom Lendacky <thomas.lendacky@amd.com>
CC: John Allen <john.allen@amd.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: "David S. Miller" <davem@davemloft.net>
CC: Michael Roth <michael.roth@amd.com>
CC: Luis Chamberlain <mcgrof@kernel.org>
CC: Russ Weight <russ.weight@linux.dev>
CC: Danilo Krummrich <dakr@redhat.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: "Rafael J. Wysocki" <rafael@kernel.org>
CC: Tianfei zhang <tianfei.zhang@intel.com>
CC: Alexey Kardashevskiy <aik@amd.com>

Co-developed-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Reviewed-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
---
 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;
 	ret = sev_platform_init(&init_args);
 	if (ret)
 		goto e_free;
-- 
2.47.0.199.ga7371fff76-goog
Re: [PATCH v4 6/6] KVM: SVM: Delay legacy platform initialization on SNP
Posted by Tom Lendacky 2 weeks, 3 days ago
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@google.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> CC: Thomas Gleixner <tglx@linutronix.de>
> CC: Ingo Molnar <mingo@redhat.com>
> CC: Borislav Petkov <bp@alien8.de>
> CC: Dave Hansen <dave.hansen@linux.intel.com>
> CC: Ashish Kalra <ashish.kalra@amd.com>
> CC: Tom Lendacky <thomas.lendacky@amd.com>
> CC: John Allen <john.allen@amd.com>
> CC: Herbert Xu <herbert@gondor.apana.org.au>
> CC: "David S. Miller" <davem@davemloft.net>
> CC: Michael Roth <michael.roth@amd.com>
> CC: Luis Chamberlain <mcgrof@kernel.org>
> CC: Russ Weight <russ.weight@linux.dev>
> CC: Danilo Krummrich <dakr@redhat.com>
> CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> CC: "Rafael J. Wysocki" <rafael@kernel.org>
> CC: Tianfei zhang <tianfei.zhang@intel.com>
> CC: Alexey Kardashevskiy <aik@amd.com>
> 
> Co-developed-by: Ashish Kalra <ashish.kalra@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> Reviewed-by: Ashish Kalra <ashish.kalra@amd.com>
> Signed-off-by: Dionna Glaze <dionnaglaze@google.com>
> ---
>  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;