diff mbox series

kselftest: kvm/arm64: Skip tests if we can't create a vgic-v3

Message ID 20220125192851.3907611-1-broonie@kernel.org (mailing list archive)
State New
Headers show
Series kselftest: kvm/arm64: Skip tests if we can't create a vgic-v3 | expand

Commit Message

Mark Brown Jan. 25, 2022, 7:28 p.m. UTC
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 <broonie@kernel.org>
---
 tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++-
 tools/testing/selftests/kvm/aarch64/vgic_irq.c   | 5 +++++
 tools/testing/selftests/kvm/lib/aarch64/vgic.c   | 4 +++-
 3 files changed, 14 insertions(+), 2 deletions(-)

Comments

Shuah Khan Jan. 25, 2022, 7:48 p.m. UTC | #1
On 1/25/22 12:28 PM, 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 <broonie@kernel.org>
> ---
>   tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++-
>   tools/testing/selftests/kvm/aarch64/vgic_irq.c   | 5 +++++
>   tools/testing/selftests/kvm/lib/aarch64/vgic.c   | 4 +++-
>   3 files changed, 14 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..791d38404652 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) {
> +		pr_info("Failed to create vgic-v3, skipping\n");
> +		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..8c6b61b8e6aa 100644
> --- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> +++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> @@ -761,6 +761,11 @@ 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) {
> +		pr_info("Failed to create vgic-v3, skipping\n");
> +		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..647c18733e1b 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);
> +	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);

Assume the flag change is intentional. The reason isn't obvious in the
change log
  
> +	if (gic_fd == -1)
> +		return -1;
>   
>   	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS,
>   			0, &nr_irqs, true);
> 

Looks good to me otherwise - thanks for adding the skips

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah
Ricardo Koller Jan. 26, 2022, 1:23 a.m. UTC | #2
On Tue, Jan 25, 2022 at 07:28:51PM +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 <broonie@kernel.org>
> ---
>  tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++-
>  tools/testing/selftests/kvm/aarch64/vgic_irq.c   | 5 +++++
>  tools/testing/selftests/kvm/lib/aarch64/vgic.c   | 4 +++-
>  3 files changed, 14 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..791d38404652 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) {
> +		pr_info("Failed to create vgic-v3, skipping\n");
> +		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..8c6b61b8e6aa 100644
> --- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> +++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
> @@ -761,6 +761,11 @@ 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) {
> +		pr_info("Failed to create vgic-v3, skipping\n");
> +		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..647c18733e1b 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);
> +	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);
> +	if (gic_fd == -1)
> +		return -1;
>  
>  	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS,
>  			0, &nr_irqs, true);
> -- 
> 2.30.2
> 
> _______________________________________________
> kvmarm mailing list
> kvmarm@lists.cs.columbia.edu
> https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Reviewed-by: Ricardo Koller <ricarkol@google.com>
Marc Zyngier Jan. 26, 2022, 9:07 a.m. UTC | #3
On Tue, 25 Jan 2022 19:28:51 +0000,
Mark Brown <broonie@kernel.org> 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 <broonie@kernel.org>
> ---
>  tools/testing/selftests/kvm/aarch64/arch_timer.c | 7 ++++++-
>  tools/testing/selftests/kvm/aarch64/vgic_irq.c   | 5 +++++
>  tools/testing/selftests/kvm/lib/aarch64/vgic.c   | 4 +++-
>  3 files changed, 14 insertions(+), 2 deletions(-)
>

[...]

> diff --git a/tools/testing/selftests/kvm/lib/aarch64/vgic.c b/tools/testing/selftests/kvm/lib/aarch64/vgic.c
> index b3a0fca0d780..647c18733e1b 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);
> +	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);

So you now only test whether it is possible to create a virtual GICv3,
but don't actually create it. How does this work?

	M.
Mark Brown Jan. 26, 2022, 12:52 p.m. UTC | #4
On Wed, Jan 26, 2022 at 09:07:48AM +0000, Marc Zyngier wrote:
> Mark Brown <broonie@kernel.org> wrote:

> >  	/* Distributor setup */
> > -	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false);
> > +	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);

> So you now only test whether it is possible to create a virtual GICv3,
> but don't actually create it. How does this work?

Oh, that's rather obscure in the API - so the file descriptor returned
if the test flag is specified can't actually be used?
Marc Zyngier Jan. 26, 2022, 1:05 p.m. UTC | #5
On Wed, 26 Jan 2022 12:52:22 +0000,
Mark Brown <broonie@kernel.org> wrote:
> 
> On Wed, Jan 26, 2022 at 09:07:48AM +0000, Marc Zyngier wrote:
> > Mark Brown <broonie@kernel.org> wrote:
> 
> > >  	/* Distributor setup */
> > > -	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, false);
> > > +	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);
> 
> > So you now only test whether it is possible to create a virtual GICv3,
> > but don't actually create it. How does this work?
> 
> Oh, that's rather obscure in the API - so the file descriptor returned
> if the test flag is specified can't actually be used?

No file descriptor is returned at all from the kernel, so you should
always get -1 as populated by kvm_create_device().

See virt/kvm/kvm_main.c::kvm_ioctl_create_device().

	M.
Mark Brown Jan. 26, 2022, 1:21 p.m. UTC | #6
On Wed, Jan 26, 2022 at 01:05:01PM +0000, Marc Zyngier wrote:
> Mark Brown <broonie@kernel.org> wrote:

> > > So you now only test whether it is possible to create a virtual GICv3,
> > > but don't actually create it. How does this work?

> > Oh, that's rather obscure in the API - so the file descriptor returned
> > if the test flag is specified can't actually be used?

> No file descriptor is returned at all from the kernel, so you should
> always get -1 as populated by kvm_create_device().

> See virt/kvm/kvm_main.c::kvm_ioctl_create_device().

Ugh, right - the descriptor is returned separately to the return code
but is then mapped onto the return code by the library since the library
just aborts on error in the non-test case and in the test case the kernel
returns an inverted boolean which gets passed straight through.  Like I
say the API seems a bit confusing here.
Marc Zyngier Jan. 26, 2022, 1:32 p.m. UTC | #7
aOn Wed, 26 Jan 2022 13:21:17 +0000,
Mark Brown <broonie@kernel.org> wrote:
> 
> [1  <text/plain; us-ascii (7bit)>]
> On Wed, Jan 26, 2022 at 01:05:01PM +0000, Marc Zyngier wrote:
> > Mark Brown <broonie@kernel.org> wrote:
> 
> > > > So you now only test whether it is possible to create a virtual GICv3,
> > > > but don't actually create it. How does this work?
> 
> > > Oh, that's rather obscure in the API - so the file descriptor returned
> > > if the test flag is specified can't actually be used?
> 
> > No file descriptor is returned at all from the kernel, so you should
> > always get -1 as populated by kvm_create_device().
> 
> > See virt/kvm/kvm_main.c::kvm_ioctl_create_device().
> 
> Ugh, right - the descriptor is returned separately to the return code
> but is then mapped onto the return code by the library since the library
> just aborts on error in the non-test case and in the test case the kernel
> returns an inverted boolean which gets passed straight through.  Like I
> say the API seems a bit confusing here.

That's a very... "kind" way of putting it.

	M.
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/aarch64/arch_timer.c b/tools/testing/selftests/kvm/aarch64/arch_timer.c
index 9ad38bd360a4..791d38404652 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) {
+		pr_info("Failed to create vgic-v3, skipping\n");
+		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..8c6b61b8e6aa 100644
--- a/tools/testing/selftests/kvm/aarch64/vgic_irq.c
+++ b/tools/testing/selftests/kvm/aarch64/vgic_irq.c
@@ -761,6 +761,11 @@  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) {
+		pr_info("Failed to create vgic-v3, skipping\n");
+		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..647c18733e1b 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);
+	gic_fd = kvm_create_device(vm, KVM_DEV_TYPE_ARM_VGIC_V3, true);
+	if (gic_fd == -1)
+		return -1;
 
 	kvm_device_access(gic_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS,
 			0, &nr_irqs, true);