Re: [PATCH v5 1/3] KVM: selftests: aarch64: Add helper function for the vpmu vcpu creation

[Eric Auger <eauger@redhat.com>]

Hi Shaoqin,

On 2/29/24 07:56, Shaoqin Huang wrote:
> Create a vcpu with vpmu would be a common requirement for the vpmu test,
> so add the helper function for the vpmu vcpu creation. And use those
> helper function in the vpmu_counter_access.c test.
> 
> Use this chance to delete the meaningless ASSERT about the pmuver,
> because KVM does not advertise an IMP_DEF PMU to guests.
> 
> No functional changes intended.
> 
> Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
> ---
>  .../kvm/aarch64/vpmu_counter_access.c         | 33 ++++---------------
>  .../selftests/kvm/include/aarch64/vpmu.h      | 29 ++++++++++++++++
>  2 files changed, 36 insertions(+), 26 deletions(-)
>  create mode 100644 tools/testing/selftests/kvm/include/aarch64/vpmu.h
> 
> diff --git a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
> index 5f9713364693..e068a0a7a43b 100644
> --- a/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
> +++ b/tools/testing/selftests/kvm/aarch64/vpmu_counter_access.c
> @@ -16,6 +16,7 @@
>  #include <processor.h>
>  #include <test_util.h>
>  #include <vgic.h>
> +#include <vpmu.h>
>  #include <perf/arm_pmuv3.h>
>  #include <linux/bitfield.h>
>  
> @@ -426,18 +427,8 @@ static void guest_code(uint64_t expected_pmcr_n)
>  /* Create a VM that has one vCPU with PMUv3 configured. */
>  static void create_vpmu_vm(void *guest_code)
>  {
> -	struct kvm_vcpu_init init;
> -	uint8_t pmuver, ec;
> -	uint64_t dfr0, irq = 23;
> -	struct kvm_device_attr irq_attr = {
> -		.group = KVM_ARM_VCPU_PMU_V3_CTRL,
> -		.attr = KVM_ARM_VCPU_PMU_V3_IRQ,
> -		.addr = (uint64_t)&irq,
> -	};
> -	struct kvm_device_attr init_attr = {
> -		.group = KVM_ARM_VCPU_PMU_V3_CTRL,
> -		.attr = KVM_ARM_VCPU_PMU_V3_INIT,
> -	};
> +	uint8_t ec;
> +	uint64_t irq = 23;
>  
>  	/* The test creates the vpmu_vm multiple times. Ensure a clean state */
>  	memset(&vpmu_vm, 0, sizeof(vpmu_vm));
> @@ -449,27 +440,17 @@ static void create_vpmu_vm(void *guest_code)
>  					guest_sync_handler);
>  	}
>  
> -	/* Create vCPU with PMUv3 */
> -	vm_ioctl(vpmu_vm.vm, KVM_ARM_PREFERRED_TARGET, &init);
> -	init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3);
> -	vpmu_vm.vcpu = aarch64_vcpu_add(vpmu_vm.vm, 0, &init, guest_code);
> +	vpmu_vm.vcpu = vm_vcpu_add_with_vpmu(vpmu_vm.vm, 0, guest_code);
>  	vcpu_init_descriptor_tables(vpmu_vm.vcpu);
> +
>  	vpmu_vm.gic_fd = vgic_v3_setup(vpmu_vm.vm, 1, 64,
>  					GICD_BASE_GPA, GICR_BASE_GPA);
>  	__TEST_REQUIRE(vpmu_vm.gic_fd >= 0,
>  		       "Failed to create vgic-v3, skipping");
>  
> -	/* Make sure that PMUv3 support is indicated in the ID register */
> -	vcpu_get_reg(vpmu_vm.vcpu,
> -		     KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &dfr0);
> -	pmuver = FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), dfr0);
> -	TEST_ASSERT(pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF &&
> -		    pmuver >= ID_AA64DFR0_EL1_PMUVer_IMP,
> -		    "Unexpected PMUVER (0x%x) on the vCPU with PMUv3", pmuver);
> -
>  	/* Initialize vPMU */
> -	vcpu_ioctl(vpmu_vm.vcpu, KVM_SET_DEVICE_ATTR, &irq_attr);
> -	vcpu_ioctl(vpmu_vm.vcpu, KVM_SET_DEVICE_ATTR, &init_attr);
> +	vpmu_set_irq(vpmu_vm.vcpu, irq);
> +	vpmu_init(vpmu_vm.vcpu);
>  }
>  
>  static void destroy_vpmu_vm(void)
> diff --git a/tools/testing/selftests/kvm/include/aarch64/vpmu.h b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
> new file mode 100644
> index 000000000000..0dfcc7ab1c4d
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/include/aarch64/vpmu.h
> @@ -0,0 +1,29 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#include <kvm_util.h>
> +
> +static inline struct kvm_vcpu *vm_vcpu_add_with_vpmu(struct kvm_vm *vm,
> +						     uint32_t vcpu_id,
> +						     void *guest_code)
> +{
> +	struct kvm_vcpu_init init;
> +
> +	/* Create vCPU with PMUv3 */
> +	vm_ioctl(vm, KVM_ARM_PREFERRED_TARGET, &init);
> +	init.features[0] |= (1 << KVM_ARM_VCPU_PMU_V3);
> +
> +	return aarch64_vcpu_add(vm, 0, &init, guest_code);
> +}
> +
> +static void vpmu_set_irq(struct kvm_vcpu *vcpu, int irq)
> +{
> +	kvm_device_attr_set(vcpu->fd, KVM_ARM_VCPU_PMU_V3_CTRL,
> +			    KVM_ARM_VCPU_PMU_V3_IRQ, &irq);
> +}
> +
> +static void vpmu_init(struct kvm_vcpu *vcpu)
> +{
> +	kvm_device_attr_set(vcpu->fd, KVM_ARM_VCPU_PMU_V3_CTRL,
> +			    KVM_ARM_VCPU_PMU_V3_INIT, NULL);
> +}
> +
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric