Re: [PATCH v2 2/3] KVM: s390: selftests: Extended user_operexec tests

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Thu,  7 May 2026 22:08:35 +0200
Eric Farman <farman@linux.ibm.com> wrote:

> There is a possibility that the user_operexec capability
> only works if facility bit 74 is enabled. This is now fixed,
> but add a selftest to demonstrate that.
> 
> Signed-off-by: Eric Farman <farman@linux.ibm.com>

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>


> ---
>  .../selftests/kvm/include/s390/facility.h     |   6 +
>  .../selftests/kvm/s390/user_operexec.c        | 110 ++++++++++++++++++
>  2 files changed, 116 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/include/s390/facility.h b/tools/testing/selftests/kvm/include/s390/facility.h
> index 41a265742666..e5259f63be22 100644
> --- a/tools/testing/selftests/kvm/include/s390/facility.h
> +++ b/tools/testing/selftests/kvm/include/s390/facility.h
> @@ -11,6 +11,7 @@
>  #ifndef SELFTEST_KVM_FACILITY_H
>  #define SELFTEST_KVM_FACILITY_H
>  
> +#include <linux/atomic.h>
>  #include <linux/bitops.h>
>  
>  /* alt_stfle_fac_list[16] + stfle_fac_list[16] */
> @@ -19,6 +20,11 @@
>  extern u64 stfl_doublewords[NB_STFL_DOUBLEWORDS];
>  extern bool stfle_flag;
>  
> +static inline bool clear_bit_inv(unsigned long nr, unsigned long *ptr)
> +{
> +	return clear_bit(nr ^ (BITS_PER_LONG - 1), ptr);
> +}
> +
>  static inline bool test_bit_inv(unsigned long nr, const unsigned long *ptr)
>  {
>  	return test_bit(nr ^ (BITS_PER_LONG - 1), ptr);
> diff --git a/tools/testing/selftests/kvm/s390/user_operexec.c b/tools/testing/selftests/kvm/s390/user_operexec.c
> index 714906c1d12a..b24c1f9dbbe8 100644
> --- a/tools/testing/selftests/kvm/s390/user_operexec.c
> +++ b/tools/testing/selftests/kvm/s390/user_operexec.c
> @@ -6,6 +6,7 @@
>   * Authors:
>   *  Janosch Frank <frankja@linux.ibm.com>
>   */
> +#include "facility.h"
>  #include "kselftest.h"
>  #include "kvm_util.h"
>  #include "test_util.h"
> @@ -109,6 +110,111 @@ static void test_user_operexec_combined(void)
>  	kvm_vm_free(vm);
>  }
>  
> +static struct kvm_vm *create_vm_without_sthyi(void)
> +{
> +	struct kvm_s390_vm_cpu_processor info;
> +	struct kvm_vm *vm;
> +
> +	vm = vm_create(1);
> +
> +	kvm_device_attr_get(vm->fd, KVM_S390_VM_CPU_MODEL,
> +			    KVM_S390_VM_CPU_PROCESSOR, &info);
> +
> +	clear_bit_inv(74, (unsigned long *)&info.fac_list);
> +	kvm_device_attr_set(vm->fd, KVM_S390_VM_CPU_MODEL,
> +			    KVM_S390_VM_CPU_PROCESSOR, &info);
> +
> +	return vm;
> +}
> +
> +static void test_user_instr0_no_stfle_74(void)
> +{
> +	struct kvm_vcpu *vcpu;
> +	struct kvm_vm *vm;
> +	int rc;
> +
> +	vm = create_vm_without_sthyi();
> +
> +	rc = __vm_enable_cap(vm, KVM_CAP_S390_USER_INSTR0, 0);
> +	TEST_ASSERT_EQ(0, rc);
> +
> +	vcpu = vm_vcpu_add(vm, 0, guest_code_instr0);
> +
> +	vcpu_run(vcpu);
> +	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_S390_SIEIC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, ICPT_OPEREXC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x0000);
> +
> +	kvm_vm_free(vm);
> +}
> +
> +static void test_user_operexec_no_stfle_74(void)
> +{
> +	struct kvm_vcpu *vcpu;
> +	struct kvm_vm *vm;
> +	int rc;
> +
> +	vm = create_vm_without_sthyi();
> +
> +	rc = __vm_enable_cap(vm, KVM_CAP_S390_USER_OPEREXEC, 0);
> +	TEST_ASSERT_EQ(0, rc);
> +
> +	vcpu = vm_vcpu_add(vm, 0, guest_code_user_operexec);
> +
> +	vcpu_run(vcpu);
> +	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_S390_SIEIC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, ICPT_OPEREXC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x0807);
> +
> +	kvm_vm_free(vm);
> +}
> +
> +static void test_instr0_combined_no_stfle_74(void)
> +{
> +	struct kvm_vcpu *vcpu;
> +	struct kvm_vm *vm;
> +	int rc;
> +
> +	vm = create_vm_without_sthyi();
> +
> +	rc = __vm_enable_cap(vm, KVM_CAP_S390_USER_INSTR0, 0);
> +	TEST_ASSERT_EQ(0, rc);
> +	rc = __vm_enable_cap(vm, KVM_CAP_S390_USER_OPEREXEC, 0);
> +	TEST_ASSERT_EQ(0, rc);
> +
> +	vcpu = vm_vcpu_add(vm, 0, guest_code_instr0);
> +
> +	vcpu_run(vcpu);
> +	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_S390_SIEIC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, ICPT_OPEREXC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x0000);
> +
> +	kvm_vm_free(vm);
> +}
> +
> +static void test_operexec_combined_no_stfle_74(void)
> +{
> +	struct kvm_vcpu *vcpu;
> +	struct kvm_vm *vm;
> +	int rc;
> +
> +	vm = create_vm_without_sthyi();
> +
> +	rc = __vm_enable_cap(vm, KVM_CAP_S390_USER_INSTR0, 0);
> +	TEST_ASSERT_EQ(0, rc);
> +	rc = __vm_enable_cap(vm, KVM_CAP_S390_USER_OPEREXEC, 0);
> +	TEST_ASSERT_EQ(0, rc);
> +
> +	vcpu = vm_vcpu_add(vm, 0, guest_code_user_operexec);
> +
> +	vcpu_run(vcpu);
> +	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_S390_SIEIC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.icptcode, ICPT_OPEREXC);
> +	TEST_ASSERT_EQ(vcpu->run->s390_sieic.ipa, 0x0807);
> +
> +	kvm_vm_free(vm);
> +}
> +
>  /*
>   * Run all tests above.
>   *
> @@ -122,6 +228,10 @@ static struct testdef {
>  	{ "instr0", test_user_instr0 },
>  	{ "operexec", test_user_operexec },
>  	{ "operexec_combined", test_user_operexec_combined},
> +	{ "instr0_no_stfle_74", test_user_instr0_no_stfle_74 },
> +	{ "instr0_combined_no_stfle_74", test_instr0_combined_no_stfle_74 },
> +	{ "operexec_combined_no_stfle_74", test_operexec_combined_no_stfle_74 },
> +	{ "operexec_no_stfle_74", test_user_operexec_no_stfle_74 },
>  };
>  
>  int main(int argc, char *argv[])