From: Michal Wajdeczko Date: Tue, 1 Jul 2025 22:00:52 +0000 (+0200) Subject: drm/xe/pf: Clear all LMTT pages on alloc X-Git-Tag: v6.16-rc6~10^2~1^2~9 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=705a412a367f383430fa34bada387af2e52eb043;p=thirdparty%2Flinux.git drm/xe/pf: Clear all LMTT pages on alloc Our LMEM buffer objects are not cleared by default on alloc and during VF provisioning we only setup LMTT PTEs for the actually provisioned LMEM range. But beyond that valid range we might leave some stale data that could either point to some other VFs allocations or even to the PF pages. Explicitly clear all new LMTT page to avoid the risk that a malicious VF would try to exploit that gap. While around add asserts to catch any undesired PTE overwrites and low-level debug traces to track LMTT PT life-cycle. Fixes: b1d204058218 ("drm/xe/pf: Introduce Local Memory Translation Table") Signed-off-by: Michal Wajdeczko Cc: Michał Winiarski Cc: Lukasz Laguna Reviewed-by: Michał Winiarski Reviewed-by: Piotr Piórkowski Link: https://lore.kernel.org/r/20250701220052.1612-1-michal.wajdeczko@intel.com (cherry picked from commit 3fae6918a3e27cce20ded2551f863fb05d4bef8d) Signed-off-by: Lucas De Marchi --- diff --git a/drivers/gpu/drm/xe/xe_lmtt.c b/drivers/gpu/drm/xe/xe_lmtt.c index 63db66df064b..023ed6a6b49d 100644 --- a/drivers/gpu/drm/xe/xe_lmtt.c +++ b/drivers/gpu/drm/xe/xe_lmtt.c @@ -78,6 +78,9 @@ static struct xe_lmtt_pt *lmtt_pt_alloc(struct xe_lmtt *lmtt, unsigned int level } lmtt_assert(lmtt, xe_bo_is_vram(bo)); + lmtt_debug(lmtt, "level=%u addr=%#llx\n", level, (u64)xe_bo_main_addr(bo, XE_PAGE_SIZE)); + + xe_map_memset(lmtt_to_xe(lmtt), &bo->vmap, 0, 0, bo->size); pt->level = level; pt->bo = bo; @@ -91,6 +94,9 @@ out: static void lmtt_pt_free(struct xe_lmtt_pt *pt) { + lmtt_debug(&pt->bo->tile->sriov.pf.lmtt, "level=%u addr=%llx\n", + pt->level, (u64)xe_bo_main_addr(pt->bo, XE_PAGE_SIZE)); + xe_bo_unpin_map_no_vm(pt->bo); kfree(pt); } @@ -226,9 +232,14 @@ static void lmtt_write_pte(struct xe_lmtt *lmtt, struct xe_lmtt_pt *pt, switch (lmtt->ops->lmtt_pte_size(level)) { case sizeof(u32): + lmtt_assert(lmtt, !overflows_type(pte, u32)); + lmtt_assert(lmtt, !pte || !iosys_map_rd(&pt->bo->vmap, idx * sizeof(u32), u32)); + xe_map_wr(lmtt_to_xe(lmtt), &pt->bo->vmap, idx * sizeof(u32), u32, pte); break; case sizeof(u64): + lmtt_assert(lmtt, !pte || !iosys_map_rd(&pt->bo->vmap, idx * sizeof(u64), u64)); + xe_map_wr(lmtt_to_xe(lmtt), &pt->bo->vmap, idx * sizeof(u64), u64, pte); break; default: