6.15-stable review patch. If anyone has any objections, please let me know.
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From: Michal Wajdeczko michal.wajdeczko@intel.com
[ Upstream commit 705a412a367f383430fa34bada387af2e52eb043 ]
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 michal.wajdeczko@intel.com Cc: Michał Winiarski michal.winiarski@intel.com Cc: Lukasz Laguna lukasz.laguna@intel.com Reviewed-by: Michał Winiarski michal.winiarski@intel.com Reviewed-by: Piotr Piórkowski piotr.piorkowski@intel.com Link: https://lore.kernel.org/r/20250701220052.1612-1-michal.wajdeczko@intel.com (cherry picked from commit 3fae6918a3e27cce20ded2551f863fb05d4bef8d) Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/xe/xe_lmtt.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/xe/xe_lmtt.c b/drivers/gpu/drm/xe/xe_lmtt.c index 89393dcb53d9d..1337cf49f1c20 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 @@ static struct xe_lmtt_pt *lmtt_pt_alloc(struct xe_lmtt *lmtt, unsigned int level
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: