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

Pratik Rajesh Sampat
2025-01-13T20:10:26Z

On 1/13/25 2:18 AM, Nikunj A. Dadhania wrote:
>
>
> 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@amd.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 ?
>

That's right, thanks for catching that. I'll get rid of the
is_sev_es_vm() check here.

Pratik