Re: [PATCH v4 15/17] iommufd: Add a selftest

From: Nicolin Chen <nicolinc@nvidia.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: <bpf@vger.kernel.org>, Jonathan Corbet <corbet@lwn.net>,
	David Woodhouse <dwmw2@infradead.org>, <iommu@lists.linux.dev>,
	Joerg Roedel <joro@8bytes.org>, Kevin Tian <kevin.tian@intel.com>,
	<linux-doc@vger.kernel.org>, <linux-kselftest@vger.kernel.org>,
	<llvm@lists.linux.dev>, Nathan Chancellor <nathan@kernel.org>,
	"Nick Desaulniers" <ndesaulniers@google.com>,
	Miguel Ojeda <ojeda@kernel.org>,
	"Robin Murphy" <robin.murphy@arm.com>,
	Shuah Khan <shuah@kernel.org>,
	"Suravee Suthikulpanit" <suravee.suthikulpanit@amd.com>,
	Tom Rix <trix@redhat.com>, Will Deacon <will@kernel.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Lu Baolu <baolu.lu@linux.intel.com>,
	Chaitanya Kulkarni <chaitanyak@nvidia.com>,
	Cornelia Huck <cohuck@redhat.com>,
	Daniel Jordan <daniel.m.jordan@oracle.com>,
	David Gibson <david@gibson.dropbear.id.au>,
	Eric Auger <eric.auger@redhat.com>,
	Eric Farman <farman@linux.ibm.com>,
	"Jason Wang" <jasowang@redhat.com>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	Joao Martins <joao.m.martins@oracle.com>, <kvm@vger.kernel.org>,
	"Matthew Rosato" <mjrosato@linux.ibm.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Niklas Schnelle <schnelle@linux.ibm.com>,
	Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>,
	Yi Liu <yi.l.liu@intel.com>, "Keqian Zhu" <zhukeqian1@huawei.com>
Subject: Re: [PATCH v4 15/17] iommufd: Add a selftest
Date: Mon, 7 Nov 2022 21:48:32 -0800	[thread overview]
Message-ID: <Y2ntsDi4RSLtUVKm@Asurada-Nvidia> (raw)
In-Reply-To: <15-v4-0de2f6c78ed0+9d1-iommufd_jgg@nvidia.com>

On Mon, Nov 07, 2022 at 08:49:08PM -0400, Jason Gunthorpe wrote:

> diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c

> +TEST_F(iommufd, cmd_length)
> +{
> +#define TEST_LENGTH(_struct, _ioctl)                                     \
> +	{                                                                \
> +		struct {                                                 \
> +			struct _struct cmd;                              \
> +			uint8_t extra;                                   \
> +		} cmd = { .cmd = { .size = sizeof(struct _struct) - 1 }, \
> +			  .extra = UINT8_MAX };                          \
> +		int old_errno;                                           \
> +		int rc;                                                  \
> +									 \
> +		EXPECT_ERRNO(EOPNOTSUPP, ioctl(self->fd, _ioctl, &cmd)); \

I guess it should be EINVAL corresponding to updated kernel code?

> +TEST_F(iommufd, cmd_ex_fail)
> +{
> +	struct {
> +		struct iommu_destroy cmd;
> +		__u64 future;
> +	} cmd = { .cmd = { .size = sizeof(cmd), .id = 0 } };
> +
> +	/* object id is invalid and command is longer */
> +	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_DESTROY, &cmd));
> +	/* future area is non-zero */
> +	cmd.future = 1;
> +	EXPECT_ERRNO(E2BIG, ioctl(self->fd, IOMMU_DESTROY, &cmd));
> +	/* Original command "works" */
> +	cmd.cmd.size = sizeof(cmd.cmd);
> +	EXPECT_ERRNO(ENOENT, ioctl(self->fd, IOMMU_DESTROY, &cmd));
> +	/* Short command fails */
> +	cmd.cmd.size = sizeof(cmd.cmd) - 1;
> +	EXPECT_ERRNO(EOPNOTSUPP, ioctl(self->fd, IOMMU_DESTROY, &cmd));

Ditto

> +TEST_HARNESS_MAIN
> diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c

> +static void fail_nth_first(struct __test_metadata *_metadata,
> +			   struct fail_nth_state *nth_state)
> +{
> +	char buf[300];
> +
> +	snprintf(buf, sizeof(buf), "/proc/self/task/%u/fail-nth", gettid());

Not sure what's missing, I have a build error at gettid. Copying
a solution from tools/perf/jvmti/jvmti_agent.c file, can fix with:
------------------------------

diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c
index 99eaa9f32e0b..7704b3a754d3 100644
--- a/tools/testing/selftests/iommu/iommufd_fail_nth.c
+++ b/tools/testing/selftests/iommu/iommufd_fail_nth.c
@@ -19,6 +19,7 @@
 
 #define __EXPORTED_HEADERS__
 #include <linux/vfio.h>
+#include <syscall.h> /* for gettid() */
 
 #include "iommufd_utils.h"
 
@@ -84,6 +85,13 @@ struct fail_nth_state {
        unsigned int iteration;
 };
 
+#ifndef HAVE_GETTID
+static inline pid_t gettid(void)
+{
+       return (pid_t)syscall(__NR_gettid);
+}
+#endif
+
 static void fail_nth_first(struct __test_metadata *_metadata,
                           struct fail_nth_state *nth_state)
 {
------------------------------
