Re: [igt-dev] [PATCH i-g-t 15/24] i915: Add gem_vm_create

Tvrtko Ursulin
2019-03-26T11:21:13Z

On 22/03/2019 09:21, Chris Wilson wrote:
> Exercise basic creation and swapping between new address spaces.
>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> ---
> lib/Makefile.sources | 2 +
> lib/i915/gem_vm.c | 130 ++++++++++++++++++++
> lib/i915/gem_vm.h | 38 ++++++
> lib/meson.build | 1 +
> tests/Makefile.sources | 1 +
> tests/i915/gem_vm_create.c | 236 +++++++++++++++++++++++++++++++++++++
> tests/meson.build | 1 +
> 7 files changed, 409 insertions(+)
> create mode 100644 lib/i915/gem_vm.c
> create mode 100644 lib/i915/gem_vm.h
> create mode 100644 tests/i915/gem_vm_create.c
>
> diff --git a/lib/Makefile.sources b/lib/Makefile.sources
> index e00347f94..a7074209a 100644
> --- a/lib/Makefile.sources
> +++ b/lib/Makefile.sources
> @@ -13,6 +13,8 @@ lib_source_list = \
> i915/gem_ring.c \
> i915/gem_mman.c \
> i915/gem_mman.h \
> + i915/gem_vm.c \
> + i915/gem_vm.h \
> i915_3d.h \
> i915_reg.h \
> i915_pciids.h \
> diff --git a/lib/i915/gem_vm.c b/lib/i915/gem_vm.c
> new file mode 100644
> index 000000000..e0d46d509
> --- /dev/null
> +++ b/lib/i915/gem_vm.c
> @@ -0,0 +1,130 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include <errno.h>
> +#include <string.h>
> +
> +#include "ioctl_wrappers.h"
> +#include "drmtest.h"
> +
> +#include "i915/gem_vm.h"
> +
> +/**
> + * SECTION:gem_vm
> + * @short_description: Helpers for dealing with address spaces (vm/GTT)
> + * @title: GEM Virtual Memory
> + *
> + * This helper library contains functions used for handling gem address
> + * spaces..
> + */
> +
> +/**
> + * gem_has_vm:
> + * @i915: open i915 drm file descriptor
> + *
> + * Returns: whether VM creation is supported or not.
> + */
> +bool gem_has_vm(int i915)
> +{
> + uint32_t vm_id = 0;
> +
> + __gem_vm_create(i915, &vm_id);
> + if (vm_id)
> + gem_vm_destroy(i915, vm_id);
> +
> + return vm_id;
> +}
> +
> +/**
> + * gem_require_vm:
> + * @i915: open i915 drm file descriptor
> + *
> + * This helper will automatically skip the test on platforms where address
> + * space creation is not available.
> + */
> +void gem_require_vm(int i915)
> +{
> + igt_require(gem_has_vm(i915));
> +}
> +
> +int __gem_vm_create(int i915, uint32_t *vm_id)
> +{
> + struct drm_i915_gem_vm_control ctl = {};
> + int err = 0;
> +
> + if (igt_ioctl(i915, DRM_IOCTL_I915_GEM_VM_CREATE, &ctl) == 0) {
> + *vm_id = ctl.vm_id;
> + } else {
> + err = -errno;
> + igt_assume(err != 0);
> + }
> +
> + errno = 0;
> + return err;
> +}
> +
> +/**
> + * gem_vm_create:
> + * @i915: open i915 drm file descriptor
> + *
> + * This wraps the VM_CREATE ioctl, which is used to allocate a new
> + * vm_set_caching() this wrapper skips on

auto-complete? :)

> + * kernels and platforms where address space support is not available.
> + *
> + * Returns: The id of the allocated address space.
> + */
> +uint32_t gem_vm_create(int i915)
> +{
> + uint32_t vm_id;
> +
> + igt_assert_eq(__gem_vm_create(i915, &vm_id), 0);
> + igt_assert(vm_id != 0);
> +
> + return vm_id;
> +}
> +
> +int __gem_vm_destroy(int i915, uint32_t vm_id)
> +{
> + struct drm_i915_gem_vm_control ctl = { .vm_id = vm_id };
> + int err = 0;
> +
> + if (igt_ioctl(i915, DRM_IOCTL_I915_GEM_VM_DESTROY, &ctl)) {
> + err = -errno;
> + igt_assume(err);
> + }
> +
> + errno = 0;
> + return err;
> +}
> +
> +/**
> + * gem_vm_destroy:
> + * @i915: open i915 drm file descriptor
> + * @vm_id: i915 VM id
> + *
> + * This wraps the VM_DESTROY ioctl, which is used to free an address space.
> + */
> +void gem_vm_destroy(int i915, uint32_t vm_id)
> +{
> + igt_assert_eq(__gem_vm_destroy(i915, vm_id), 0);
> +}
> diff --git a/lib/i915/gem_vm.h b/lib/i915/gem_vm.h
> new file mode 100644
> index 000000000..27af899d4
> --- /dev/null
> +++ b/lib/i915/gem_vm.h
> @@ -0,0 +1,38 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#ifndef GEM_VM_H
> +#define GEM_VM_H
> +
> +#include <stdint.h>
> +
> +bool gem_has_vm(int i915);
> +void gem_require_vm(int i915);
> +
> +uint32_t gem_vm_create(int i915);
> +int __gem_vm_create(int i915, uint32_t *vm_id);
> +
> +void gem_vm_destroy(int i915, uint32_t vm_id);
> +int __gem_vm_destroy(int i915, uint32_t vm_id);
> +
> +#endif /* GEM_VM_H */
> diff --git a/lib/meson.build b/lib/meson.build
> index 89de06e69..f95922330 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -5,6 +5,7 @@ lib_sources = [
> 'i915/gem_submission.c',
> 'i915/gem_ring.c',
> 'i915/gem_mman.c',
> + 'i915/gem_vm.c',
> 'igt_color_encoding.c',
> 'igt_debugfs.c',
> 'igt_device.c',
> diff --git a/tests/Makefile.sources b/tests/Makefile.sources
> index 71ccf00af..809b25612 100644
> --- a/tests/Makefile.sources
> +++ b/tests/Makefile.sources
> @@ -21,6 +21,7 @@ TESTS_progs = \
> drm_import_export \
> drm_mm \
> drm_read \
> + i915/gem_vm_create \

It looked like strange placement at first and then I opened the file and
got reminded of the horror.

> kms_3d \
> kms_addfb_basic \
> kms_atomic \
> diff --git a/tests/i915/gem_vm_create.c b/tests/i915/gem_vm_create.c
> new file mode 100644
> index 000000000..0264fa301
> --- /dev/null
> +++ b/tests/i915/gem_vm_create.c
> @@ -0,0 +1,236 @@
> +/*
> + * Copyright © 2019 Intel Corporation
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> + * IN THE SOFTWARE.
> + */
> +
> +#include "igt.h"
> +#include "igt_dummyload.h"
> +#include "i915/gem_vm.h"
> +
> +static int __gem_vm_create_local(int i915, struct drm_i915_gem_vm_control *ctl)

Bikeshedding only, but local suffix scared me you are using local ioctl
definitions. On closer look, since functions are local, you could afford
to use names like vm_create/vm_destroy.

> +{
> + int err = 0;
> + if (igt_ioctl(i915, DRM_IOCTL_I915_GEM_VM_CREATE, ctl)) {
> + err = -errno;
> + igt_assume(err);
> + }
> + errno = 0;
> + return err;
> +}
> +
> +static int __gem_vm_destroy_local(int i915, struct drm_i915_gem_vm_control *ctl)
> +{
> + int err = 0;
> + if (igt_ioctl(i915, DRM_IOCTL_I915_GEM_VM_DESTROY, ctl)) {
> + err = -errno;
> + igt_assume(err);
> + }
> + errno = 0;
> + return err;
> +}
> +
> +static bool has_vm(int i915)
> +{
> + struct drm_i915_gem_vm_control ctl = {};
> + int err;
> +
> + err = __gem_vm_create_local(i915, &ctl);
> + switch (err) {
> + case -EINVAL: /* unknown ioctl */
> + case -ENODEV: /* !full-ppgtt */
> + return false;
> +
> + case 0:
> + gem_vm_destroy(i915, ctl.vm_id);
> + return true;
> +
> + default:
> + igt_fail_on_f(err, "Unknown response from VM_CREATE\n");
> + return false;
> + }
> +}
> +
> +static void invalid_create(int i915)
> +{
> + struct drm_i915_gem_vm_control ctl = {};
> + struct i915_user_extension ext = { .name = -1 };
> +
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), 0);
> + gem_vm_destroy(i915, ctl.vm_id);
> +
> + ctl.vm_id = 0xdeadbeef;
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), 0);
> + gem_vm_destroy(i915, ctl.vm_id);
> + ctl.vm_id = 0;

Oh we allow garbage in.. hm.. perhaps disallow that?

Otherwise both tests here are not invalid input/behaviour. First is also
covered by has_vm.

> +
> + ctl.flags = -1;
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), -EINVAL);
> + ctl.flags = 0;
> +
> + ctl.extensions = -1;
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), -EFAULT);
> + ctl.extensions = to_user_pointer(&ext);
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), -EINVAL);
> + ctl.extensions = 0;

Could add a loop rejection test as well, even though the underlying
implementation is shared.

> +}
> +
> +static void invalid_destroy(int i915)
> +{
> + struct drm_i915_gem_vm_control ctl = {};
> +
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), -ENOENT);

Should we have id 0 be -EINVAL?

> +
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), 0);
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), 0);
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), -ENOENT);
> +
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), 0);
> + ctl.vm_id = ctl.vm_id + 1; /* XXX assume cyclic allocator */

I think this actually assumes, and correctly so, that the fd is clean
ie. only the created vm_id has been allocated. So comment needs to be
corrected I think.

> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), -ENOENT);
> + ctl.vm_id = ctl.vm_id - 1;
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), 0);
> +
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), 0);
> + ctl.flags = -1;
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), -EINVAL);
> + ctl.flags = 0;
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), 0);

Second create-destroy is redundant but okay.

> +
> + igt_assert_eq(__gem_vm_create_local(i915, &ctl), 0);
> + ctl.extensions = -1;
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), -EINVAL);
> + ctl.extensions = 0;
> + igt_assert_eq(__gem_vm_destroy_local(i915, &ctl), 0);
> +}
> +
> +static uint32_t __batch_create(int i915, uint32_t offset)
> +{
> + const uint32_t bbe = MI_BATCH_BUFFER_END;
> + uint32_t handle;
> +
> + handle = gem_create(i915, ALIGN(offset + 4, 4096));
> + gem_write(i915, handle, offset, &bbe, sizeof(bbe));
> +
> + return handle;
> +}
> +
> +static uint32_t batch_create(int i915)
> +{
> + return __batch_create(i915, 0);
> +}

Oi! :D

> +
> +static void execbuf(int i915)
> +{
> + struct drm_i915_gem_exec_object2 batch = {
> + .handle = batch_create(i915),
> + };
> + struct drm_i915_gem_execbuffer2 eb = {
> + .buffers_ptr = to_user_pointer(&batch),
> + .buffer_count = 1,
> + };
> + struct drm_i915_gem_context_param arg = {
> + .param = I915_CONTEXT_PARAM_VM,
> + };
> +
> + /* First verify that we try to use "softpinning" by default */
> + batch.offset = 48 << 20;

Choice of 48 is a bit misleading, but okay.

> + gem_execbuf(i915, &eb);
> + igt_assert_eq_u64(batch.offset, 48 << 20);
> +
> + arg.value = gem_vm_create(i915);
> + gem_context_set_param(i915, &arg);
> + gem_execbuf(i915, &eb);
> + igt_assert_eq_u64(batch.offset, 48 << 20);

Not sure what the offset check proves in this case? It's a new ppgtt, or
even if was old one. Seems it would never fail?

> + gem_vm_destroy(i915, arg.value);
> +
> + arg.value = gem_vm_create(i915);
> + gem_context_set_param(i915, &arg);
> + batch.offset = 0;
> + gem_execbuf(i915, &eb);
> + igt_assert_eq_u64(batch.offset, 0);
> + gem_vm_destroy(i915, arg.value);
> +
> + gem_sync(i915, batch.handle);
> + gem_close(i915, batch.handle);
> +}
> +
> +static void async_destroy(int i915)
> +{
> + struct drm_i915_gem_context_param arg = {
> + .ctx_id = gem_context_create(i915),
> + .value = gem_vm_create(i915),
> + .param = I915_CONTEXT_PARAM_VM,
> + };
> + igt_spin_t *spin[2];
> +
> + spin[0] = igt_spin_batch_new(i915,
> + .ctx = arg.ctx_id,
> + .flags = IGT_SPIN_POLL_RUN);
> + igt_spin_busywait_until_running(spin[0]);
> +
> + gem_context_set_param(i915, &arg);
> + spin[1] = __igt_spin_batch_new(i915, .ctx = arg.ctx_id);
> +
> + igt_spin_batch_end(spin[0]);
> + gem_sync(i915, spin[0]->handle);
> +
> + gem_vm_destroy(i915, arg.value);
> + gem_context_destroy(i915, arg.ctx_id);
> +
> + igt_spin_batch_end(spin[1]);
> + gem_sync(i915, spin[1]->handle);
> +
> + for (int i = 0; i < ARRAY_SIZE(spin); i++)
> + igt_spin_batch_free(i915, spin[i]);
> +}
> +
> +igt_main
> +{
> + int i915 = -1;
> +
> + igt_fixture {
> + i915 = drm_open_driver(DRIVER_INTEL);
> + igt_require_gem(i915);
> + igt_require(has_vm(i915));
> + }
> +
> + igt_subtest("invalid-create")
> + invalid_create(i915);
> +
> + igt_subtest("invalid-destroy")
> + invalid_destroy(i915);
> +
> + igt_subtest_group {
> + igt_fixture {
> + gem_context_require_param(i915, I915_CONTEXT_PARAM_VM);
> + }
> +
> + igt_subtest("execbuf")
> + execbuf(i915);
> +
> + igt_subtest("async-destroy")
> + async_destroy(i915);
> + }
> +
> + igt_fixture {
> + close(i915);
> + }
> +}
> diff --git a/tests/meson.build b/tests/meson.build
> index 9015f809e..949eefd6f 100644
> --- a/tests/meson.build
> +++ b/tests/meson.build
> @@ -209,6 +209,7 @@ i915_progs = [
> 'gem_unfence_active_buffers',
> 'gem_unref_active_buffers',
> 'gem_userptr_blits',
> + 'gem_vm_create',
> 'gem_wait',
> 'gem_workarounds',
> 'gem_write_read_ring_switch',
>

Regards,

Tvrtko