drm/i915/gvt: Refine pte shadowing process

Make the shadow PTE population code clear. Later we will add huge gtt
support based on this.

v2:
  - rebase to latest code.

Signed-off-by: Changbin Du <changbin.du@intel.com>
Reviewed-by: Zhi Wang <zhi.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

1 files changed, 94 insertions, 79 deletions

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index b15b9e55a997..7b4a345a0d52 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -453,29 +453,6 @@ static struct intel_gvt_gtt_gma_ops gen8_gtt_gma_ops = {
         .gma_to_pml4_index = gen8_gma_to_pml4_index,
 };
 
-static int gtt_entry_p2m(struct intel_vgpu *vgpu, struct intel_gvt_gtt_entry *p,
-                struct intel_gvt_gtt_entry *m)
-{
-        struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
-        unsigned long gfn, mfn;
-
-        *m = *p;
-
-        if (!ops->test_present(p))
-                return 0;
-
-        gfn = ops->get_pfn(p);
-
-        mfn = intel_gvt_hypervisor_gfn_to_mfn(vgpu, gfn);
-        if (mfn == INTEL_GVT_INVALID_ADDR) {
-                gvt_vgpu_err("fail to translate gfn: 0x%lx\n", gfn);
-                return -ENXIO;
-        }
-
-        ops->set_pfn(m, mfn);
-        return 0;
-}
-
 /*
  * MM helpers.
  */
@@ -943,8 +920,7 @@ static int ppgtt_invalidate_shadow_page_by_shadow_entry(struct intel_vgpu *vgpu,
         struct intel_vgpu_ppgtt_spt *s;
         intel_gvt_gtt_type_t cur_pt_type;
 
-        if (WARN_ON(!gtt_type_is_pt(get_next_pt_type(e->type))))
-                return -EINVAL;
+        GEM_BUG_ON(!gtt_type_is_pt(get_next_pt_type(e->type)));
 
         if (e->type != GTT_TYPE_PPGTT_ROOT_L3_ENTRY
                 && e->type != GTT_TYPE_PPGTT_ROOT_L4_ENTRY) {
@@ -982,14 +958,26 @@ static int ppgtt_invalidate_shadow_page(struct intel_vgpu_ppgtt_spt *spt)
                 goto release;
 
         for_each_present_shadow_entry(spt, &e, index) {
-                if (!gtt_type_is_pt(get_next_pt_type(e.type))) {
-                        gvt_vgpu_err("GVT doesn't support pse bit for now\n");
-                        return -EINVAL;
+                switch (e.type) {
+                case GTT_TYPE_PPGTT_PTE_4K_ENTRY:
+                        gvt_vdbg_mm("invalidate 4K entry\n");
+                        continue;
+                case GTT_TYPE_PPGTT_PTE_2M_ENTRY:
+                case GTT_TYPE_PPGTT_PTE_1G_ENTRY:
+                        WARN(1, "GVT doesn't support 2M/1GB page\n");
+                        continue;
+                case GTT_TYPE_PPGTT_PML4_ENTRY:
+                case GTT_TYPE_PPGTT_PDP_ENTRY:
+                case GTT_TYPE_PPGTT_PDE_ENTRY:
+                        gvt_vdbg_mm("invalidate PMUL4/PDP/PDE entry\n");
+                        ret = ppgtt_invalidate_shadow_page_by_shadow_entry(
+                                        spt->vgpu, &e);
+                        if (ret)
+                                goto fail;
+                        break;
+                default:
+                        GEM_BUG_ON(1);
                 }
-                ret = ppgtt_invalidate_shadow_page_by_shadow_entry(
-                                spt->vgpu, &e);
-                if (ret)
-                        goto fail;
         }
 release:
         trace_spt_change(spt->vgpu->id, "release", spt,
@@ -1013,10 +1001,7 @@ static struct intel_vgpu_ppgtt_spt *ppgtt_populate_shadow_page_by_guest_entry(
         struct intel_vgpu_page_track *t;
         int ret;
 
-        if (WARN_ON(!gtt_type_is_pt(get_next_pt_type(we->type)))) {
-                ret = -EINVAL;
-                goto fail;
-        }
+        GEM_BUG_ON(!gtt_type_is_pt(get_next_pt_type(we->type)));
 
         t = intel_vgpu_find_tracked_page(vgpu, ops->get_pfn(we));
         if (t) {
@@ -1062,6 +1047,41 @@ static inline void ppgtt_generate_shadow_entry(struct intel_gvt_gtt_entry *se,
         ops->set_pfn(se, s->shadow_page.mfn);
 }
 
+static int ppgtt_populate_shadow_entry(struct intel_vgpu *vgpu,
+        struct intel_vgpu_ppgtt_spt *spt, unsigned long index,
+        struct intel_gvt_gtt_entry *ge)
+{
+        struct intel_gvt_gtt_pte_ops *pte_ops = vgpu->gvt->gtt.pte_ops;
+        struct intel_gvt_gtt_entry se = *ge;
+        unsigned long gfn, mfn;
+
+        if (!pte_ops->test_present(ge))
+                return 0;
+
+        gfn = pte_ops->get_pfn(ge);
+
+        switch (ge->type) {
+        case GTT_TYPE_PPGTT_PTE_4K_ENTRY:
+                gvt_vdbg_mm("shadow 4K gtt entry\n");
+                break;
+        case GTT_TYPE_PPGTT_PTE_2M_ENTRY:
+        case GTT_TYPE_PPGTT_PTE_1G_ENTRY:
+                gvt_vgpu_err("GVT doesn't support 2M/1GB entry\n");
+                return -EINVAL;
+        default:
+                GEM_BUG_ON(1);
+        };
+
+        /* direct shadow */
+        mfn = intel_gvt_hypervisor_gfn_to_mfn(vgpu, gfn);
+        if (mfn == INTEL_GVT_INVALID_ADDR)
+                return -ENXIO;
+
+        pte_ops->set_pfn(&se, mfn);
+        ppgtt_set_shadow_entry(spt, &se, index);
+        return 0;
+}
+
 static int ppgtt_populate_shadow_page(struct intel_vgpu_ppgtt_spt *spt)
 {
         struct intel_vgpu *vgpu = spt->vgpu;
@@ -1075,32 +1095,29 @@ static int ppgtt_populate_shadow_page(struct intel_vgpu_ppgtt_spt *spt)
         trace_spt_change(spt->vgpu->id, "born", spt,
                         spt->guest_page.track.gfn, spt->shadow_page.type);
 
-        if (gtt_type_is_pte_pt(spt->shadow_page.type)) {
-                for_each_present_guest_entry(spt, &ge, i) {
+        for_each_present_guest_entry(spt, &ge, i) {
+                if (gtt_type_is_pt(get_next_pt_type(ge.type))) {
+                        s = ppgtt_populate_shadow_page_by_guest_entry(vgpu,
+                                                                      &ge);
+                        if (IS_ERR(s)) {
+                                ret = PTR_ERR(s);
+                                goto fail;
+                        }
+                        ppgtt_get_shadow_entry(spt, &se, i);
+                        ppgtt_generate_shadow_entry(&se, s, &ge);
+                        ppgtt_set_shadow_entry(spt, &se, i);
+                } else {
                         gfn = ops->get_pfn(&ge);
-                        if (!intel_gvt_hypervisor_is_valid_gfn(vgpu, gfn) ||
-                                gtt_entry_p2m(vgpu, &ge, &se))
+                        if (!intel_gvt_hypervisor_is_valid_gfn(vgpu, gfn)) {
                                 ops->set_pfn(&se, gvt->gtt.scratch_mfn);
-                        ppgtt_set_shadow_entry(spt, &se, i);
-                }
-                return 0;
-        }
-
-        for_each_present_guest_entry(spt, &ge, i) {
-                if (!gtt_type_is_pt(get_next_pt_type(ge.type))) {
-                        gvt_vgpu_err("GVT doesn't support pse bit now\n");
-                        ret = -EINVAL;
-                        goto fail;
-                }
+                                ppgtt_set_shadow_entry(spt, &se, i);
+                                continue;
+                        }
 
-                s = ppgtt_populate_shadow_page_by_guest_entry(vgpu, &ge);
-                if (IS_ERR(s)) {
-                        ret = PTR_ERR(s);
-                        goto fail;
+                        ret = ppgtt_populate_shadow_entry(vgpu, spt, i, &ge);
+                        if (ret)
+                                goto fail;
                 }
-                ppgtt_get_shadow_entry(spt, &se, i);
-                ppgtt_generate_shadow_entry(&se, s, &ge);
-                ppgtt_set_shadow_entry(spt, &se, i);
         }
         return 0;
 fail:
@@ -1175,10 +1192,9 @@ static int ppgtt_handle_guest_entry_add(struct intel_vgpu_guest_page *gpt,
                 ppgtt_generate_shadow_entry(&m, s, we);
                 ppgtt_set_shadow_entry(spt, &m, index);
         } else {
-                ret = gtt_entry_p2m(vgpu, we, &m);
+                ret = ppgtt_populate_shadow_entry(vgpu, spt, index, we);
                 if (ret)
                         goto fail;
-                ppgtt_set_shadow_entry(spt, &m, index);
         }
         return 0;
 fail:
@@ -1195,7 +1211,7 @@ static int sync_oos_page(struct intel_vgpu *vgpu,
         struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops;
         struct intel_vgpu_ppgtt_spt *spt =
                 guest_page_to_ppgtt_spt(oos_page->guest_page);
-        struct intel_gvt_gtt_entry old, new, m;
+        struct intel_gvt_gtt_entry old, new;
         int index;
         int ret;
 
@@ -1219,12 +1235,11 @@ static int sync_oos_page(struct intel_vgpu *vgpu,
                                 oos_page->guest_page, spt->guest_page_type,
                                 new.val64, index);
 
-                ret = gtt_entry_p2m(vgpu, &new, &m);
+                ret = ppgtt_populate_shadow_entry(vgpu, spt, index, &new);
                 if (ret)
                         return ret;
 
                 ops->set_entry(oos_page->mem, &new, index, false, 0, vgpu);
-                ppgtt_set_shadow_entry(spt, &m, index);
         }
 
         oos_page->guest_page->write_cnt = 0;
@@ -1371,10 +1386,9 @@ static int ppgtt_handle_guest_write_page_table(
         struct intel_vgpu *vgpu = spt->vgpu;
         int type = spt->shadow_page.type;
         struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
-        struct intel_gvt_gtt_entry se;
-
-        int ret;
+        struct intel_gvt_gtt_entry old_se;
         int new_present;
+        int ret;
 
         new_present = ops->test_present(we);
 
@@ -1383,7 +1397,7 @@ static int ppgtt_handle_guest_write_page_table(
          * guarantee the ppgtt table is validated during the window between
          * adding and removal.
          */
-        ppgtt_get_shadow_entry(spt, &se, index);
+        ppgtt_get_shadow_entry(spt, &old_se, index);
 
         if (new_present) {
                 ret = ppgtt_handle_guest_entry_add(gpt, we, index);
@@ -1391,13 +1405,13 @@ static int ppgtt_handle_guest_write_page_table(
                         goto fail;
         }
 
-        ret = ppgtt_handle_guest_entry_removal(gpt, &se, index);
+        ret = ppgtt_handle_guest_entry_removal(gpt, &old_se, index);
         if (ret)
                 goto fail;
 
         if (!new_present) {
-                ops->set_pfn(&se, vgpu->gtt.scratch_pt[type].page_mfn);
-                ppgtt_set_shadow_entry(spt, &se, index);
+                ops->set_pfn(&old_se, vgpu->gtt.scratch_pt[type].page_mfn);
+                ppgtt_set_shadow_entry(spt, &old_se, index);
         }
 
         return 0;
@@ -1407,6 +1421,8 @@ fail:
         return ret;
 }
 
+
+
 static inline bool can_do_out_of_sync(struct intel_vgpu_guest_page *gpt)
 {
         return enable_out_of_sync
@@ -1924,9 +1940,8 @@ static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
         struct intel_vgpu_mm *ggtt_mm = vgpu->gtt.ggtt_mm;
         struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops;
         unsigned long g_gtt_index = off >> info->gtt_entry_size_shift;
-        unsigned long gma, gfn;
+        unsigned long gma, gfn, mfn;
         struct intel_gvt_gtt_entry e, m;
-        int ret;
 
         if (bytes != 4 && bytes != 8)
                 return -EINVAL;
@@ -1941,6 +1956,7 @@ static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
 
         memcpy((void *)&e.val64 + (off & (info->gtt_entry_size - 1)), p_data,
                         bytes);
+        m = e;
 
         if (ops->test_present(&e)) {
                 gfn = ops->get_pfn(&e);
@@ -1953,19 +1969,18 @@ static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
                         goto out;
                 }
 
-                ret = gtt_entry_p2m(vgpu, &e, &m);
-                if (ret) {
-                        gvt_vgpu_err("fail to translate guest gtt entry\n");
+                mfn = intel_gvt_hypervisor_gfn_to_mfn(vgpu, gfn);
+                if (mfn == INTEL_GVT_INVALID_ADDR) {
+                        gvt_vgpu_err("fail to populate guest ggtt entry\n");
                         /* guest driver may read/write the entry when partial
                          * update the entry in this situation p2m will fail
                          * settting the shadow entry to point to a scratch page
                          */
                         ops->set_pfn(&m, gvt->gtt.scratch_mfn);
-                }
-        } else {
-                m = e;
+                } else
+                        ops->set_pfn(&m, mfn);
+        } else
                 ops->set_pfn(&m, gvt->gtt.scratch_mfn);
-        }
 
 out:
         ggtt_set_host_entry(ggtt_mm, &m, g_gtt_index);