Re: [PATCH 3/4] tests/xe: Add transient display PRL skip

["Wang, X" <x.wang@intel.com>]

On 4/6/2026 11:42, Brian Nguyen wrote:
> Page reclamation may be suppressed for various reasons. In this case,
> transient display vma ranges will not use page reclamation, so ensure
> that behavior in this subtest.
>
> Signed-off-by: Brian Nguyen <brian3.nguyen@intel.com>
> Suggested-by: Xin Wang <x.wang@intel.com>
> ---
>   tests/intel/xe_page_reclaim.c | 87 +++++++++++++++++++++++++++++++++++
>   1 file changed, 87 insertions(+)
>
> diff --git a/tests/intel/xe_page_reclaim.c b/tests/intel/xe_page_reclaim.c
> index 7741063d2..6cc29d8d3 100644
> --- a/tests/intel/xe_page_reclaim.c
> +++ b/tests/intel/xe_page_reclaim.c
> @@ -4,7 +4,10 @@
>    */
>   
>   #include <fcntl.h>
> +#include <linux_scaffold.h>
>   
> +#include "igt_syncobj.h"
> +#include "intel_pat.h"
>   #include "ioctl_wrappers.h"
>   #include "xe/xe_gt.h"
>   #include "xe/xe_ioctl.h"
> @@ -44,6 +47,33 @@ static struct xe_prl_stats get_prl_stats(int fd, int gt)
>   	return stats;
>   }
>   
> +#define XE2_L3_POLICY		GENMASK(5, 4)
> +#define L3_CACHE_POLICY_XD	1
> +
> +static int get_xd_pat_idx(int fd)
> +{
> +	uint16_t dev_id = intel_get_drm_devid(fd);
> +	struct intel_pat_cache pat_config = {};
> +	int32_t parsed;
> +	int i;
> +
> +	if (intel_graphics_ver(dev_id) < IP_VER(20, 0))
> +		return -1;
> +
> +	parsed = xe_get_pat_sw_config(fd, &pat_config, 0);
> +	if (parsed <= 0)
> +		return -1;
> +
> +	for (i = 0; i < parsed; i++) {
> +		if (pat_config.entries[i].rsvd)
> +			continue;
> +		if (FIELD_GET(XE2_L3_POLICY, pat_config.entries[i].pat) == L3_CACHE_POLICY_XD)
> +			return i;
> +	}
> +
> +	return -1;
> +}
> +
>   static void log_prl_stat_diff(struct xe_prl_stats *stats_before, struct xe_prl_stats *stats_after)
>   {
>   	igt_debug("PRL stats diff: 4K: %d->%d, 64K: %d->%d, 2M: %d -> %d, issued: %d->%d, aborted: %d->%d\n",
> @@ -535,7 +565,61 @@ static void test_binds_1g_partial(int fd)
>   	stats_before = get_prl_stats(fd, 0);
>   	vma_range_list_with_unbind_and_offsets(fd, sizes, count, (1ull << 30), SZ_1G + SZ_2M, offsets);
>   	stats_after = get_prl_stats(fd, 0);
> +	compare_prl_stats(&stats_before, &stats_after, &expected_stats);
> +}
>   
> +/**
> + * SUBTEST: pat-index-xd
> + * Description: Create a VM binding with a BO that has PAT INDEX with XD
> + *      (transient display) property to test page reclamation
> + *      with transient cache entries on XE2+ platforms.
> + */
> +static void test_pat_index_xd(int fd)
> +{
> +	struct xe_prl_stats stats_before, stats_after, expected_stats = { 0 };
> +	uint32_t vm, bo;
> +	uint64_t size = SZ_4K;
> +	uint64_t addr = 1ull << 30;
> +	int pat_idx_xd, err;
> +	struct drm_xe_sync sync = {
> +		.type = DRM_XE_SYNC_TYPE_SYNCOBJ,
> +		.flags = DRM_XE_SYNC_FLAG_SIGNAL,
> +	};
> +
> +	pat_idx_xd = get_xd_pat_idx(fd);
> +	igt_require_f(pat_idx_xd >= 0, "XD PAT index not available on this platform\n");
> +
> +	vm = xe_vm_create(fd, 0, 0);
> +	bo = xe_bo_create_caching(fd, 0, size, system_memory(fd), 0,
> +				  DRM_XE_GEM_CPU_CACHING_WC);
> +
> +	/* Bind with XD PAT index - synchronous operation */
> +	sync.handle = syncobj_create(fd, 0);
> +	err = __xe_vm_bind(fd, vm, 0, bo, 0, addr,
> +			   size, DRM_XE_VM_BIND_OP_MAP, 0, &sync, 1, 0,
> +			   pat_idx_xd, 0);
> +	igt_assert_eq(err, 0);
> +	igt_assert(syncobj_wait(fd, &sync.handle, 1, INT64_MAX, 0, NULL));
> +	syncobj_destroy(fd, sync.handle);
> +
> +	/*
> +	 * Page reclamation should skip over the XD pat vma pages.
> +	 * PRL is still issued because pages are still valid, just handled
> +	 * elsewhere so no invalidation required to ensure not squashing valid
> +	 * PRL entries from other VMAs.
> +	 */
> +	expected_stats.prl_4k_entry_count = 0;
> +	expected_stats.prl_64k_entry_count = 0;
> +	expected_stats.prl_2m_entry_count = 0;
> +	expected_stats.prl_issued_count = 1;
> +	expected_stats.prl_aborted_count = 0;
> +
> +	stats_before = get_prl_stats(fd, 0);
> +	xe_vm_unbind_sync(fd, vm, 0, addr, size);
> +	stats_after = get_prl_stats(fd, 0);
> +
> +	gem_close(fd, bo);
> +	xe_vm_destroy(fd, vm);
>   	compare_prl_stats(&stats_before, &stats_after, &expected_stats);
>   }
>   
> @@ -587,6 +671,9 @@ int igt_main()
>   	igt_subtest("binds-1g-partial")
>   		test_binds_1g_partial(fd);
>   
> +	igt_subtest("pat-index-xd")
> +		test_pat_index_xd(fd);
> +
Reviewed-by: Xin Wang <x.wang@intel.com>
>   	igt_fixture()
>   		drm_close_driver(fd);
>   }