Files
linux/drivers/gpu/drm/xe/tests/xe_dma_buf.c
Thomas Hellström 5c87fee3c9 drm/xe: Attempt to bring bos back to VRAM after eviction
VRAM+TT bos that are evicted from VRAM to TT may remain in
TT also after a revalidation following eviction or suspend.

This manifests itself as applications becoming sluggish
after buffer objects get evicted or after a resume from
suspend or hibernation.

If the bo supports placement in both VRAM and TT, and
we are on DGFX, mark the TT placement as fallback. This means
that it is tried only after VRAM + eviction.

This flaw has probably been present since the xe module was
upstreamed but use a Fixes: commit below where backporting is
likely to be simple. For earlier versions we need to open-
code the fallback algorithm in the driver.

v2:
- Remove check for dgfx. (Matthew Auld)
- Update the xe_dma_buf kunit test for the new strategy (CI)
- Allow dma-buf to pin in current placement (CI)
- Make xe_bo_validate() for pinned bos a NOP.

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/5995
Fixes: a78a8da51b ("drm/ttm: replace busy placement with flags v6")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: <stable@vger.kernel.org> # v6.9+
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://lore.kernel.org/r/20250904160715.2613-2-thomas.hellstrom@linux.intel.com
(cherry picked from commit cb3d7b3b46)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-09-09 13:20:22 -04:00

288 lines
8.2 KiB
C

// SPDX-License-Identifier: GPL-2.0 AND MIT
/*
* Copyright © 2022 Intel Corporation
*/
#include <uapi/drm/xe_drm.h>
#include <kunit/test.h>
#include <kunit/visibility.h>
#include "tests/xe_kunit_helpers.h"
#include "tests/xe_pci_test.h"
#include "xe_pci.h"
#include "xe_pm.h"
static bool p2p_enabled(struct dma_buf_test_params *params)
{
return IS_ENABLED(CONFIG_PCI_P2PDMA) && params->attach_ops &&
params->attach_ops->allow_peer2peer;
}
static bool is_dynamic(struct dma_buf_test_params *params)
{
return IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY) && params->attach_ops &&
params->attach_ops->move_notify;
}
static void check_residency(struct kunit *test, struct xe_bo *exported,
struct xe_bo *imported, struct dma_buf *dmabuf)
{
struct dma_buf_test_params *params = to_dma_buf_test_params(test->priv);
u32 mem_type;
int ret;
xe_bo_assert_held(exported);
xe_bo_assert_held(imported);
mem_type = XE_PL_VRAM0;
if (!(params->mem_mask & XE_BO_FLAG_VRAM0))
/* No VRAM allowed */
mem_type = XE_PL_TT;
else if (params->force_different_devices && !p2p_enabled(params))
/* No P2P */
mem_type = XE_PL_TT;
else if (params->force_different_devices && !is_dynamic(params) &&
(params->mem_mask & XE_BO_FLAG_SYSTEM))
/* Pin migrated to TT */
mem_type = XE_PL_TT;
if (!xe_bo_is_mem_type(exported, mem_type)) {
KUNIT_FAIL(test, "Exported bo was not in expected memory type.\n");
return;
}
if (xe_bo_is_pinned(exported))
return;
/*
* Evict exporter. Note that the gem object dma_buf member isn't
* set from xe_gem_prime_export(), and it's needed for the move_notify()
* functionality, so hack that up here. Evicting the exported bo will
* evict also the imported bo through the move_notify() functionality if
* importer is on a different device. If they're on the same device,
* the exporter and the importer should be the same bo.
*/
swap(exported->ttm.base.dma_buf, dmabuf);
ret = xe_bo_evict(exported);
swap(exported->ttm.base.dma_buf, dmabuf);
if (ret) {
if (ret != -EINTR && ret != -ERESTARTSYS)
KUNIT_FAIL(test, "Evicting exporter failed with err=%d.\n",
ret);
return;
}
/* Verify that also importer has been evicted to SYSTEM */
if (exported != imported && !xe_bo_is_mem_type(imported, XE_PL_SYSTEM)) {
KUNIT_FAIL(test, "Importer wasn't properly evicted.\n");
return;
}
/* Re-validate the importer. This should move also exporter in. */
ret = xe_bo_validate(imported, NULL, false);
if (ret) {
if (ret != -EINTR && ret != -ERESTARTSYS)
KUNIT_FAIL(test, "Validating importer failed with err=%d.\n",
ret);
return;
}
KUNIT_EXPECT_TRUE(test, xe_bo_is_mem_type(exported, mem_type));
if (params->force_different_devices)
KUNIT_EXPECT_TRUE(test, xe_bo_is_mem_type(imported, XE_PL_TT));
else
KUNIT_EXPECT_TRUE(test, exported == imported);
}
static void xe_test_dmabuf_import_same_driver(struct xe_device *xe)
{
struct kunit *test = kunit_get_current_test();
struct dma_buf_test_params *params = to_dma_buf_test_params(test->priv);
struct drm_gem_object *import;
struct dma_buf *dmabuf;
struct xe_bo *bo;
size_t size;
/* No VRAM on this device? */
if (!ttm_manager_type(&xe->ttm, XE_PL_VRAM0) &&
(params->mem_mask & XE_BO_FLAG_VRAM0))
return;
size = PAGE_SIZE;
if ((params->mem_mask & XE_BO_FLAG_VRAM0) &&
xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K)
size = SZ_64K;
kunit_info(test, "running %s\n", __func__);
bo = xe_bo_create_user(xe, NULL, NULL, size, DRM_XE_GEM_CPU_CACHING_WC,
params->mem_mask);
if (IS_ERR(bo)) {
KUNIT_FAIL(test, "xe_bo_create() failed with err=%ld\n",
PTR_ERR(bo));
return;
}
dmabuf = xe_gem_prime_export(&bo->ttm.base, 0);
if (IS_ERR(dmabuf)) {
KUNIT_FAIL(test, "xe_gem_prime_export() failed with err=%ld\n",
PTR_ERR(dmabuf));
goto out;
}
import = xe_gem_prime_import(&xe->drm, dmabuf);
if (!IS_ERR(import)) {
struct xe_bo *import_bo = gem_to_xe_bo(import);
/*
* Did import succeed when it shouldn't due to lack of p2p support?
*/
if (params->force_different_devices &&
!p2p_enabled(params) &&
!(params->mem_mask & XE_BO_FLAG_SYSTEM)) {
KUNIT_FAIL(test,
"xe_gem_prime_import() succeeded when it shouldn't have\n");
} else {
int err;
/* Is everything where we expect it to be? */
xe_bo_lock(import_bo, false);
err = xe_bo_validate(import_bo, NULL, false);
/* Pinning in VRAM is not allowed. */
if (!is_dynamic(params) &&
params->force_different_devices &&
!(params->mem_mask & XE_BO_FLAG_SYSTEM))
KUNIT_EXPECT_EQ(test, err, -EINVAL);
/* Otherwise only expect interrupts or success. */
else if (err && err != -EINTR && err != -ERESTARTSYS)
KUNIT_EXPECT_TRUE(test, !err || err == -EINTR ||
err == -ERESTARTSYS);
if (!err)
check_residency(test, bo, import_bo, dmabuf);
xe_bo_unlock(import_bo);
}
drm_gem_object_put(import);
} else if (PTR_ERR(import) != -EOPNOTSUPP) {
/* Unexpected error code. */
KUNIT_FAIL(test,
"xe_gem_prime_import failed with the wrong err=%ld\n",
PTR_ERR(import));
} else if (!params->force_different_devices ||
p2p_enabled(params) ||
(params->mem_mask & XE_BO_FLAG_SYSTEM)) {
/* Shouldn't fail if we can reuse same bo, use p2p or use system */
KUNIT_FAIL(test, "dynamic p2p attachment failed with err=%ld\n",
PTR_ERR(import));
}
dma_buf_put(dmabuf);
out:
drm_gem_object_put(&bo->ttm.base);
}
static const struct dma_buf_attach_ops nop2p_attach_ops = {
.allow_peer2peer = false,
.move_notify = xe_dma_buf_move_notify
};
/*
* We test the implementation with bos of different residency and with
* importers with different capabilities; some lacking p2p support and some
* lacking dynamic capabilities (attach_ops == NULL). We also fake
* different devices avoiding the import shortcut that just reuses the same
* gem object.
*/
static const struct dma_buf_test_params test_params[] = {
{.mem_mask = XE_BO_FLAG_VRAM0,
.attach_ops = &xe_dma_buf_attach_ops},
{.mem_mask = XE_BO_FLAG_VRAM0,
.attach_ops = &xe_dma_buf_attach_ops,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_VRAM0,
.attach_ops = &nop2p_attach_ops},
{.mem_mask = XE_BO_FLAG_VRAM0,
.attach_ops = &nop2p_attach_ops,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_VRAM0},
{.mem_mask = XE_BO_FLAG_VRAM0,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_SYSTEM,
.attach_ops = &xe_dma_buf_attach_ops},
{.mem_mask = XE_BO_FLAG_SYSTEM,
.attach_ops = &xe_dma_buf_attach_ops,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_SYSTEM,
.attach_ops = &nop2p_attach_ops},
{.mem_mask = XE_BO_FLAG_SYSTEM,
.attach_ops = &nop2p_attach_ops,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_SYSTEM},
{.mem_mask = XE_BO_FLAG_SYSTEM,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_SYSTEM | XE_BO_FLAG_VRAM0,
.attach_ops = &xe_dma_buf_attach_ops},
{.mem_mask = XE_BO_FLAG_SYSTEM | XE_BO_FLAG_VRAM0,
.attach_ops = &xe_dma_buf_attach_ops,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_SYSTEM | XE_BO_FLAG_VRAM0,
.attach_ops = &nop2p_attach_ops},
{.mem_mask = XE_BO_FLAG_SYSTEM | XE_BO_FLAG_VRAM0,
.attach_ops = &nop2p_attach_ops,
.force_different_devices = true},
{.mem_mask = XE_BO_FLAG_SYSTEM | XE_BO_FLAG_VRAM0},
{.mem_mask = XE_BO_FLAG_SYSTEM | XE_BO_FLAG_VRAM0,
.force_different_devices = true},
{}
};
static int dma_buf_run_device(struct xe_device *xe)
{
const struct dma_buf_test_params *params;
struct kunit *test = kunit_get_current_test();
xe_pm_runtime_get(xe);
for (params = test_params; params->mem_mask; ++params) {
struct dma_buf_test_params p = *params;
p.base.id = XE_TEST_LIVE_DMA_BUF;
test->priv = &p;
xe_test_dmabuf_import_same_driver(xe);
}
xe_pm_runtime_put(xe);
/* A non-zero return would halt iteration over driver devices */
return 0;
}
static void xe_dma_buf_kunit(struct kunit *test)
{
struct xe_device *xe = test->priv;
dma_buf_run_device(xe);
}
static struct kunit_case xe_dma_buf_tests[] = {
KUNIT_CASE_PARAM(xe_dma_buf_kunit, xe_pci_live_device_gen_param),
{}
};
VISIBLE_IF_KUNIT
struct kunit_suite xe_dma_buf_test_suite = {
.name = "xe_dma_buf",
.test_cases = xe_dma_buf_tests,
.init = xe_kunit_helper_xe_device_live_test_init,
};
EXPORT_SYMBOL_IF_KUNIT(xe_dma_buf_test_suite);