Re: [PATCH v4 06/10] KVM: selftests: Add support for vcpu_args_set to aarch64 and s390x

[Paolo Bonzini <pbonzini@redhat.com>]

On 23/01/20 19:04, Ben Gardon wrote:
> Currently vcpu_args_set is only implemented for x86. This makes writing
> tests with multiple vCPUs difficult as each guest vCPU must either a.)
> do the same thing or b.) derive some kind of unique token from it's
> registers or the architecture. To simplify the process of writing tests
> with multiple vCPUs for s390 and aarch64, add set args functions for
> those architectures.
> 
> Signed-off-by: Ben Gardon <bgardon@google.com>
> ---
>  .../selftests/kvm/lib/aarch64/processor.c     | 33 +++++++++++++++++
>  .../selftests/kvm/lib/s390x/processor.c       | 35 +++++++++++++++++++
>  2 files changed, 68 insertions(+)
> 
> diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
> index 86036a59a668e..a2ff90a75f326 100644
> --- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
> +++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
> @@ -333,3 +333,36 @@ void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
>  {
>  	aarch64_vcpu_add_default(vm, vcpuid, NULL, guest_code);
>  }
> +
> +/* VM VCPU Args Set
> + *
> + * Input Args:
> + *   vm - Virtual Machine
> + *   vcpuid - VCPU ID
> + *   num - number of arguments
> + *   ... - arguments, each of type uint64_t
> + *
> + * Output Args: None
> + *
> + * Return: None
> + *
> + * Sets the first num function input arguments to the values
> + * given as variable args.  Each of the variable args is expected to
> + * be of type uint64_t. The registers set by this function are r0-r7.
> + */
> +void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...)
> +{
> +	va_list ap;
> +
> +	TEST_ASSERT(num >= 1 && num <= 8, "Unsupported number of args,\n"
> +		    "  num: %u\n",
> +		    num);
> +
> +	va_start(ap, num);
> +
> +	for (i = 0; i < num; i++)
> +		set_reg(vm, vcpuid, ARM64_CORE_REG(regs.regs[num]),
> +			va_arg(ap, uint64_t));
> +
> +	va_end(ap);
> +}
> diff --git a/tools/testing/selftests/kvm/lib/s390x/processor.c b/tools/testing/selftests/kvm/lib/s390x/processor.c
> index 32a02360b1eb0..680f37be9dbc9 100644
> --- a/tools/testing/selftests/kvm/lib/s390x/processor.c
> +++ b/tools/testing/selftests/kvm/lib/s390x/processor.c
> @@ -269,6 +269,41 @@ void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
>  	run->psw_addr = (uintptr_t)guest_code;
>  }
>  
> +/* VM VCPU Args Set
> + *
> + * Input Args:
> + *   vm - Virtual Machine
> + *   vcpuid - VCPU ID
> + *   num - number of arguments
> + *   ... - arguments, each of type uint64_t
> + *
> + * Output Args: None
> + *
> + * Return: None
> + *
> + * Sets the first num function input arguments to the values
> + * given as variable args.  Each of the variable args is expected to
> + * be of type uint64_t. The registers set by this function are r2-r6.
> + */
> +void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...)
> +{
> +	va_list ap;
> +	struct kvm_regs regs;
> +
> +	TEST_ASSERT(num >= 1 && num <= 5, "Unsupported number of args,\n"
> +		    "  num: %u\n",
> +		    num);
> +
> +	va_start(ap, num);
> +	vcpu_regs_get(vm, vcpuid, &regs);
> +
> +	for (i = 0; i < num; i++)
> +		regs.gprs[i + 2] = va_arg(ap, uint64_t);
> +
> +	vcpu_regs_set(vm, vcpuid, &regs);
> +	va_end(ap);
> +}
> +
>  void vcpu_dump(FILE *stream, struct kvm_vm *vm, uint32_t vcpuid, uint8_t indent)
>  {
>  	struct vcpu *vcpu = vm->vcpu_head;
> 

Squashing this:

diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index a2ff90a75f32..839a76c96f01 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -353,6 +353,7 @@ void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
 void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...)
 {
 	va_list ap;
+	int i;
 
 	TEST_ASSERT(num >= 1 && num <= 8, "Unsupported number of args,\n"
 		    "  num: %u\n",
diff --git a/tools/testing/selftests/kvm/lib/s390x/processor.c b/tools/testing/selftests/kvm/lib/s390x/processor.c
index 680f37be9dbc..a0b84235c848 100644
--- a/tools/testing/selftests/kvm/lib/s390x/processor.c
+++ b/tools/testing/selftests/kvm/lib/s390x/processor.c
@@ -289,6 +289,7 @@ void vcpu_args_set(struct kvm_vm *vm, uint32_t vcpuid, unsigned int num, ...)
 {
 	va_list ap;
 	struct kvm_regs regs;
+	int i;
 
 	TEST_ASSERT(num >= 1 && num <= 5, "Unsupported number of args,\n"
 		    "  num: %u\n",

Paolo