linux-kernel - Re: [PATCH v4 4/8] KVM: selftests: Introduce SEV VM type check

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Message-ID: <71ed4121-83dd-4b09-b1a0-1f0654512c2b@amd.com>
Date: Mon, 13 Jan 2025 13:48:43 +0530
From: "Nikunj A. Dadhania" <nikunj@....com>
To: "Pratik R. Sampat" <pratikrajesh.sampat@....com>, kvm@...r.kernel.org
Cc: seanjc@...gle.com, pbonzini@...hat.com, pgonda@...gle.com,
 thomas.lendacky@....com, michael.roth@....com, shuah@...nel.org,
 linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 4/8] KVM: selftests: Introduce SEV VM type check



On 11/15/2024 5:11 AM, Pratik R. Sampat wrote:
> In preparation for SNP, declutter the vm type check by introducing a
> SEV-SNP VM type check as well a transitive set of helper functions.
> 
> The SNP VM type is the subset of SEV-ES. Similarly, the SEV-ES and SNP
> types are subset of the SEV VM type check.
> 
> Signed-off-by: Pratik R. Sampat <pratikrajesh.sampat@....com>
> ---
>  .../testing/selftests/kvm/include/x86_64/sev.h  |  4 ++++
>  .../selftests/kvm/lib/x86_64/processor.c        |  4 ++--
>  tools/testing/selftests/kvm/lib/x86_64/sev.c    | 17 +++++++++++++++++
>  .../selftests/kvm/x86_64/sev_smoke_test.c       |  2 +-
>  4 files changed, 24 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/include/x86_64/sev.h b/tools/testing/selftests/kvm/include/x86_64/sev.h
> index e7df5d0987f6..faed91435963 100644
> --- a/tools/testing/selftests/kvm/include/x86_64/sev.h
> +++ b/tools/testing/selftests/kvm/include/x86_64/sev.h
> @@ -29,6 +29,10 @@ enum sev_guest_state {
>  
>  #define VMGEXIT()		{ __asm__ __volatile__("rep; vmmcall"); }
>  
> +bool is_sev_vm(struct kvm_vm *vm);
> +bool is_sev_es_vm(struct kvm_vm *vm);
> +bool is_sev_snp_vm(struct kvm_vm *vm);
> +
>  void sev_vm_launch(struct kvm_vm *vm, uint32_t policy);
>  void sev_vm_launch_measure(struct kvm_vm *vm, uint8_t *measurement);
>  void sev_vm_launch_finish(struct kvm_vm *vm);
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> index 636b29ba8985..13f060748fc2 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
> @@ -641,7 +641,7 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm)
>  	sync_global_to_guest(vm, host_cpu_is_amd);
>  	sync_global_to_guest(vm, is_forced_emulation_enabled);
>  
> -	if (vm->type == KVM_X86_SEV_VM || vm->type == KVM_X86_SEV_ES_VM) {
> +	if (is_sev_vm(vm)) {
>  		struct kvm_sev_init init = { 0 };
>  
>  		vm_sev_ioctl(vm, KVM_SEV_INIT2, &init);
> @@ -1158,7 +1158,7 @@ void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)
>  
>  void kvm_init_vm_address_properties(struct kvm_vm *vm)
>  {
> -	if (vm->type == KVM_X86_SEV_VM || vm->type == KVM_X86_SEV_ES_VM) {
> +	if (is_sev_vm(vm)) {
>  		vm->arch.sev_fd = open_sev_dev_path_or_exit();
>  		vm->arch.c_bit = BIT_ULL(this_cpu_property(X86_PROPERTY_SEV_C_BIT));
>  		vm->gpa_tag_mask = vm->arch.c_bit;
> diff --git a/tools/testing/selftests/kvm/lib/x86_64/sev.c b/tools/testing/selftests/kvm/lib/x86_64/sev.c
> index e9535ee20b7f..d6e7a422b69d 100644
> --- a/tools/testing/selftests/kvm/lib/x86_64/sev.c
> +++ b/tools/testing/selftests/kvm/lib/x86_64/sev.c
> @@ -4,6 +4,23 @@
>  
>  #include "sev.h"
>  
> +bool is_sev_snp_vm(struct kvm_vm *vm)
> +{
> +	return vm->type == KVM_X86_SNP_VM;
> +}
> +
> +/* A SNP VM is also a SEV-ES VM */
> +bool is_sev_es_vm(struct kvm_vm *vm)
> +{
> +	return is_sev_snp_vm(vm) || vm->type == KVM_X86_SEV_ES_VM;
> +}
> +
> +/* A SEV-ES and SNP VM is also a SEV VM */
> +bool is_sev_vm(struct kvm_vm *vm)
> +{
> +	return is_sev_snp_vm(vm) || is_sev_es_vm(vm) || vm->type == KVM_X86_SEV_VM;

As is_sev_es_vm() already checks is_sev_snp_vm(), we can drop SNP VM check here, right ?

Regards
Nikunj