Subject: Re: [PATCH v3] kselftest: kvm/arm64: Skip tests if we can't create a vgic-v3

From: Ricardo Koller <[email-masked]>
Date: Wed, 26 Jan 2022 20:16:59 -0800

On Wed, Jan 26, 2022 at 02:52:42PM +0000, Mark Brown wrote:
> The arch_timer and vgic_irq kselftests assume that they can create a
> vgic-v3, using the library function vgic_v3_setup() which aborts with a
> test failure if it is not possible to do so. Since vgic-v3 can only be
> instantiated on systems where the host has GICv3 this leads to false
> positives on older systems where that is not the case.
> 
> Fix this by changing vgic_v3_setup() to return an error if the vgic can't
> be instantiated and have the callers skip if this happens. We could also
> exit flagging a skip in vgic_v3_setup() but this would prevent future test
> cases conditionally deciding which GIC to use or generally doing more
> complex output.
> 
> Signed-off-by: Mark Brown <[email-masked]>
> ---
> 
> v3:
>  - Use custom print_skip() helper.
>  - Use internal version of _kvm_create_device.
> v2:
>  - The test for being able to create the GIC doesn't actually
>    instantiate it, add a call doing so in that case.
> 
>  tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++-
>  tools/testing/selftests/kvm/aarch64/vgic_irq.c   | 4 ++++
>  tools/testing/selftests/kvm/lib/aarch64/vgic.c   | 4 +++-
>  3 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c
> index 9ad38bd360a4..b08d30bf71c5 100644
> --- a/tools/testing/selftests/kvm/aarch64/arch_timer.c
> +++ b/tools/testing/selftests/kvm/aarch64/arch_timer.c
> @@ -366,6 +366,7 @@ static struct kvm_vm *test_vm_create(void)
>  {
>  	struct kvm_vm *vm;
>  	unsigned int i;
> +	int ret;
>  	int nr_vcpus = test_args.nr_vcpus;
>  
>  	vm = vm_create_default_with_vcpus(nr_vcpus, 0, 0, guest_code, NULL);
> @@ -382,7 +383,11 @@ static struct kvm_vm *test_vm_create(void)
>  
>  	ucall_init(vm, NULL);
>  	test_init_timer_irq(vm);
> -	vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
> +	ret = vgic_v3_setup(vm, nr_vcpus, 64, GICD_BASE_GPA, GICR_BASE_GPA);
> +	if (ret < 0) {
> +		print_skip("Failed to create vgic-v3");
> +		exit(KSFT_SKIP);
> +	}
>  
>  	/* Make all the test's cmdline args visible to the guest */
>  	sync_global_to_guest(vm, test_args);
> diff --git a/tools/testing/selftests/kvm/aarch64/vgic_irq.c b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> index e6c7d7f8fbd1..7eca97799917 100644
> --- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> +++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> @@ -761,6 +761,10 @@ static void test_vgic(uint32_t nr_irqs, bool level_sensitive, bool eoi_split)
>  
>  	gic_fd = vgic_v3_setup(vm, 1, nr_irqs,
>  			GICD_BASE_GPA, GICR_BASE_GPA);
> +	if (gic_fd < 0) {
> +		print_skip("Failed to create vgic-v3, skipping");
> +		exit(KSFT_SKIP);
> +	}
>  
>  	vm_install_exception_handler(vm, VECTOR_IRQ_CURRENT,
>  		guest_irq_handlers[args.eoi_split][args.level_sensitive]);
> diff --git a/tools/testing/selftests/kvm/lib/aarch64/vgic.c b/tools/testing/selftests/kvm/lib/aarch64/vgic.c
> index b3a0fca0d780..f5cd0c536d85 100644
> --- a/tools/testing/selftests/kvm/lib/aarch64/vgic.c
> +++ b/tools/testing/selftests/kvm/lib/aarch64/vgic.c
> @@ -52,7 +52,9 @@ int vgic_v3_setup(struct kvm_vm *vm, unsigned int nr_vcpus, uint32_t nr_irqs,
>  			nr_vcpus, nr_vcpus_created);
>  
>  	/* Distributor setup */
> -	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false);
> +	if (_kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3,
> +			       false, &gic_fd) != 0)
> +		return -1;
>  
>  	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS,
>  			0, &nr_irqs, true);
> -- 
> 2.30.2
> 
> _______________________________________________
> kvmarm mailing list
> [email-masked]
> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Tried both gicv2 and v3 and the change works as expected.

Tested-by: Ricardo Koller <[email-masked]>

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