From 9baf0920b5d8e4e4ea302cb954168e06cf838d63 Mon Sep 17 00:00:00 2001 From: Bing Niu Date: Mon, 7 Nov 2016 10:44:36 +0800 Subject: [PATCH] drm/i915/gvt: don't rely on guest PPGTT entry to free old shadow data On guest writing a PPGTT entry, if it contains value and the old entry is valid, gvt will read it and find & free the corresponding old data for it. However, with the KVM write protection provided by page_track, the guest entry will be written with new value before gvt handling. To avoid that, we should use the shadow entry instead. Signed-off-by: Bing Niu Signed-off-by: Jike Song Signed-off-by: Zhenyu Wang --- drivers/gpu/drm/i915/gvt/gtt.c | 51 ++++++++++++---------------------- 1 file changed, 17 insertions(+), 34 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c index 15f7d4e8e75d..7eaaf1c9ed2b 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c @@ -974,7 +974,7 @@ fail: } static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_guest_page *gpt, - struct intel_gvt_gtt_entry *we, unsigned long index) + unsigned long index) { struct intel_vgpu_ppgtt_spt *spt = guest_page_to_ppgtt_spt(gpt); struct intel_vgpu_shadow_page *sp = &spt->shadow_page; @@ -983,25 +983,26 @@ static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_guest_page *gpt, struct intel_gvt_gtt_entry e; int ret; - trace_gpt_change(spt->vgpu->id, "remove", spt, sp->type, - we->val64, index); - ppgtt_get_shadow_entry(spt, &e, index); + + trace_gpt_change(spt->vgpu->id, "remove", spt, sp->type, e.val64, + index); + if (!ops->test_present(&e)) return 0; if (ops->get_pfn(&e) == vgpu->gtt.scratch_pt[sp->type].page_mfn) return 0; - if (gtt_type_is_pt(get_next_pt_type(we->type))) { - struct intel_vgpu_guest_page *g = - intel_vgpu_find_guest_page(vgpu, ops->get_pfn(we)); - if (!g) { + if (gtt_type_is_pt(get_next_pt_type(e.type))) { + struct intel_vgpu_ppgtt_spt *s = + ppgtt_find_shadow_page(vgpu, ops->get_pfn(&e)); + if (!s) { gvt_err("fail to find guest page\n"); ret = -ENXIO; goto fail; } - ret = ppgtt_invalidate_shadow_page(guest_page_to_ppgtt_spt(g)); + ret = ppgtt_invalidate_shadow_page(s); if (ret) goto fail; } @@ -1010,7 +1011,7 @@ static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_guest_page *gpt, return 0; fail: gvt_err("vgpu%d: fail: shadow page %p guest entry 0x%llx type %d\n", - vgpu->id, spt, we->val64, we->type); + vgpu->id, spt, e.val64, e.type); return ret; } @@ -1231,23 +1232,16 @@ static int ppgtt_handle_guest_write_page_table( struct intel_vgpu_ppgtt_spt *spt = guest_page_to_ppgtt_spt(gpt); struct intel_vgpu *vgpu = spt->vgpu; struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops; - struct intel_gvt_gtt_entry ge; - int old_present, new_present; int ret; + int new_present; - ppgtt_get_guest_entry(spt, &ge, index); - - old_present = ops->test_present(&ge); new_present = ops->test_present(we); - ppgtt_set_guest_entry(spt, we, index); + ret = ppgtt_handle_guest_entry_removal(gpt, index); + if (ret) + goto fail; - if (old_present) { - ret = ppgtt_handle_guest_entry_removal(gpt, &ge, index); - if (ret) - goto fail; - } if (new_present) { ret = ppgtt_handle_guest_entry_add(gpt, we, index); if (ret) @@ -1293,7 +1287,7 @@ int intel_vgpu_flush_post_shadow(struct intel_vgpu *vgpu) { struct list_head *pos, *n; struct intel_vgpu_ppgtt_spt *spt; - struct intel_gvt_gtt_entry ge, e; + struct intel_gvt_gtt_entry ge; unsigned long index; int ret; @@ -1304,9 +1298,6 @@ int intel_vgpu_flush_post_shadow(struct intel_vgpu *vgpu) for_each_set_bit(index, spt->post_shadow_bitmap, GTT_ENTRY_NUM_IN_ONE_PAGE) { ppgtt_get_guest_entry(spt, &ge, index); - e = ge; - e.val64 = 0; - ppgtt_set_guest_entry(spt, &e, index); ret = ppgtt_handle_guest_write_page_table( &spt->guest_page, &ge, index); @@ -1334,8 +1325,6 @@ static int ppgtt_handle_guest_write_page_table_bytes(void *gp, index = (pa & (PAGE_SIZE - 1)) >> info->gtt_entry_size_shift; ppgtt_get_guest_entry(spt, &we, index); - memcpy((void *)&we.val64 + (pa & (info->gtt_entry_size - 1)), - p_data, bytes); ops->test_pse(&we); @@ -1344,19 +1333,13 @@ static int ppgtt_handle_guest_write_page_table_bytes(void *gp, if (ret) return ret; } else { - struct intel_gvt_gtt_entry ge; - - ppgtt_get_guest_entry(spt, &ge, index); - if (!test_bit(index, spt->post_shadow_bitmap)) { - ret = ppgtt_handle_guest_entry_removal(gpt, - &ge, index); + ret = ppgtt_handle_guest_entry_removal(gpt, index); if (ret) return ret; } ppgtt_set_post_shadow(spt, index); - ppgtt_set_guest_entry(spt, &we, index); } if (!enable_out_of_sync) -- 2.20.1