From e448372e8a8ed2708ac4f85d74979885e47d5566 Mon Sep 17 00:00:00 2001 From: Michal Wajdeczko Date: Wed, 12 Nov 2025 13:44:08 +0100 Subject: [PATCH] drm/xe/pf: Use migration-friendly GGTT auto-provisioning MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Instead of trying very hard to find the largest fair GGTT size that could be allocated for VFs on the current tile, pick some smaller rounded down to power-of-two value that is more likely to be provisioned in the same manner by the other PF instance: num VFs | GGTT space (MiB) --------+----------------- 63..57 | 56 56..29 | 64 28..15 | 128 14..8 | 256 7..4 | 512 3..2 | 1024 1 | 2048 (regular PF) 1 | 3584 (admin only PF) Note that due to FW/HW limitations we can't share all 4GiB GGTT address space with VFs, so for the larger (>7) number of the VFs the change in the outcome is happening at different points than we have in case of GuC contexts/doorbells IDs. Signed-off-by: Michal Wajdeczko Reviewed-by: Piotr Piórkowski Link: https://patch.msgid.link/20251112124408.8094-1-michal.wajdeczko@intel.com --- .../xe/tests/xe_gt_sriov_pf_config_kunit.c | 46 +++++++++++++++++++ drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c | 23 ++++++++++ 2 files changed, 69 insertions(+) diff --git a/drivers/gpu/drm/xe/tests/xe_gt_sriov_pf_config_kunit.c b/drivers/gpu/drm/xe/tests/xe_gt_sriov_pf_config_kunit.c index cb3db3e793e15..42bfc4bcfbcfe 100644 --- a/drivers/gpu/drm/xe/tests/xe_gt_sriov_pf_config_kunit.c +++ b/drivers/gpu/drm/xe/tests/xe_gt_sriov_pf_config_kunit.c @@ -145,11 +145,57 @@ static void fair_doorbells(struct kunit *test) KUNIT_ASSERT_EQ(test, SZ_128, pf_profile_fair_dbs(gt, num_vfs)); } +static void fair_ggtt_1vf(struct kunit *test) +{ + struct xe_gt *gt = test->priv; + struct xe_device *xe = gt_to_xe(gt); + + pf_set_admin_mode(xe, false); + KUNIT_ASSERT_FALSE(test, xe_sriov_pf_admin_only(xe)); + KUNIT_EXPECT_EQ(test, SZ_2G, pf_profile_fair_ggtt(gt, 1)); + + pf_set_admin_mode(xe, true); + KUNIT_ASSERT_TRUE(test, xe_sriov_pf_admin_only(xe)); + KUNIT_EXPECT_EQ(test, SZ_2G + SZ_1G + SZ_512M, pf_profile_fair_ggtt(gt, 1)); +} + +static void fair_ggtt(struct kunit *test) +{ + unsigned int num_vfs = (unsigned long)test->param_value; + struct xe_gt *gt = test->priv; + struct xe_device *xe = gt_to_xe(gt); + u64 alignment = pf_get_ggtt_alignment(gt); + u64 shareable = SZ_2G + SZ_1G + SZ_512M; + + pf_set_admin_mode(xe, false); + KUNIT_ASSERT_FALSE(test, xe_sriov_pf_admin_only(xe)); + + KUNIT_EXPECT_TRUE(test, IS_ALIGNED(pf_profile_fair_ggtt(gt, num_vfs), alignment)); + KUNIT_EXPECT_GE(test, shareable, num_vfs * pf_profile_fair_ggtt(gt, num_vfs)); + + if (num_vfs > 56) + KUNIT_ASSERT_EQ(test, SZ_64M - SZ_8M, pf_profile_fair_ggtt(gt, num_vfs)); + else if (num_vfs > 28) + KUNIT_ASSERT_EQ(test, SZ_64M, pf_profile_fair_ggtt(gt, num_vfs)); + else if (num_vfs > 14) + KUNIT_ASSERT_EQ(test, SZ_128M, pf_profile_fair_ggtt(gt, num_vfs)); + else if (num_vfs > 7) + KUNIT_ASSERT_EQ(test, SZ_256M, pf_profile_fair_ggtt(gt, num_vfs)); + else if (num_vfs > 3) + KUNIT_ASSERT_EQ(test, SZ_512M, pf_profile_fair_ggtt(gt, num_vfs)); + else if (num_vfs > 1) + KUNIT_ASSERT_EQ(test, SZ_1G, pf_profile_fair_ggtt(gt, num_vfs)); + else + KUNIT_ASSERT_EQ(test, SZ_2G, pf_profile_fair_ggtt(gt, num_vfs)); +} + static struct kunit_case pf_gt_config_test_cases[] = { KUNIT_CASE(fair_contexts_1vf), KUNIT_CASE(fair_doorbells_1vf), + KUNIT_CASE(fair_ggtt_1vf), KUNIT_CASE_PARAM(fair_contexts, num_vfs_gen_param), KUNIT_CASE_PARAM(fair_doorbells, num_vfs_gen_param), + KUNIT_CASE_PARAM(fair_ggtt, num_vfs_gen_param), {} }; diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c index 9c14f02961355..62f6cc45a7640 100644 --- a/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c +++ b/drivers/gpu/drm/xe/xe_gt_sriov_pf_config.c @@ -9,6 +9,7 @@ #include "abi/guc_actions_sriov_abi.h" #include "abi/guc_klvs_abi.h" +#include "regs/xe_gtt_defs.h" #include "regs/xe_guc_regs.h" #include "xe_bo.h" @@ -697,6 +698,22 @@ static u64 pf_estimate_fair_ggtt(struct xe_gt *gt, unsigned int num_vfs) return fair; } +static u64 pf_profile_fair_ggtt(struct xe_gt *gt, unsigned int num_vfs) +{ + bool admin_only_pf = xe_sriov_pf_admin_only(gt_to_xe(gt)); + u64 shareable = ALIGN_DOWN(GUC_GGTT_TOP, SZ_512M); + u64 alignment = pf_get_ggtt_alignment(gt); + + if (admin_only_pf && num_vfs == 1) + return ALIGN_DOWN(shareable, alignment); + + /* need to hardcode due to ~512M of GGTT being reserved */ + if (num_vfs > 56) + return SZ_64M - SZ_8M; + + return rounddown_pow_of_two(shareable / num_vfs); +} + /** * xe_gt_sriov_pf_config_set_fair_ggtt - Provision many VFs with fair GGTT. * @gt: the &xe_gt (can't be media) @@ -710,6 +727,7 @@ static u64 pf_estimate_fair_ggtt(struct xe_gt *gt, unsigned int num_vfs) int xe_gt_sriov_pf_config_set_fair_ggtt(struct xe_gt *gt, unsigned int vfid, unsigned int num_vfs) { + u64 profile = pf_profile_fair_ggtt(gt, num_vfs); u64 fair; xe_gt_assert(gt, vfid); @@ -723,6 +741,11 @@ int xe_gt_sriov_pf_config_set_fair_ggtt(struct xe_gt *gt, unsigned int vfid, if (!fair) return -ENOSPC; + fair = min(fair, profile); + if (fair < profile) + xe_gt_sriov_info(gt, "Using non-profile provisioning (%s %llu vs %llu)\n", + "GGTT", fair, profile); + return xe_gt_sriov_pf_config_bulk_set_ggtt(gt, vfid, num_vfs, fair); } -- 2.47.3