[v3,1/2] drm/i915/gvt: Fix guest vGPU hang caused by very high dma setup overhead

Submitted by changbin.du@intel.com on March 1, 2018, 2:04 a.m.

Details

Message ID 1519869874-6750-2-git-send-email-changbin.du@intel.com
State New
Headers show
Series "Fix guest vGPU hang" ( rev: 1 ) in Intel GVT devel

Not browsing as part of any series.

Commit Message

changbin.du@intel.com March 1, 2018, 2:04 a.m.
From: Changbin Du <changbin.du@intel.com>

The implementation of current kvmgt implicitly setup dma mapping at MPT
API gfn_to_mfn. First this design against the API's original purpose.
Second, there is no unmap hit in this design. The result is that the
dma mapping keep growing larger and larger. For mutl-vm case, they will
consume IOMMU IOVA low 4GB address space quickly and so tons of rbtree
entries crated in the IOMMU IOVA allocator. Finally, single IOVA
allocation can take as long as ~70ms. Such latency is intolerable.

To address both above issues, this patch introduced two new MPT API:
  o dma_map_guest_page - setup dma map for guest page
  o dma_unmap_guest_page - cancel dma map for guest page

The kvmgt implements these 2 API. And to reduce dma setup overhead for
duplicated pages (eg. scratch pages), two caches are used: one is for
mapping gfn to struct gvt_dma, another is for mapping dma addr to
struct gvt_dma.

With these 2 new API, the gtt now is able to cancel dma mapping when page
table is invalidated. The dma mapping is not in a gradual increase now.

v2: follow the old logic for VFIO_IOMMU_NOTIFY_DMA_UNMAP at this point.

Cc: Hang Yuan <hang.yuan@intel.com>
Cc: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Changbin Du <changbin.du@intel.com>
---
 drivers/gpu/drm/i915/gvt/gtt.c       |  50 ++++--
 drivers/gpu/drm/i915/gvt/gvt.h       |   9 +-
 drivers/gpu/drm/i915/gvt/hypercall.h |   5 +
 drivers/gpu/drm/i915/gvt/kvmgt.c     | 288 ++++++++++++++++++++---------------
 drivers/gpu/drm/i915/gvt/mpt.h       |  28 ++++
 5 files changed, 246 insertions(+), 134 deletions(-)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index 8fb4f102..0a100a2 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -822,6 +822,23 @@  static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu,
 	return ppgtt_invalidate_spt(s);
 }
 
+static inline void ppgtt_invalidate_pte(struct intel_vgpu_ppgtt_spt *spt,
+		struct intel_gvt_gtt_entry *entry)
+{
+	struct intel_vgpu *vgpu = spt->vgpu;
+	struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
+	unsigned long pfn;
+	int type;
+
+	pfn = ops->get_pfn(entry);
+	type = spt->shadow_page.type;
+
+	if (pfn == vgpu->gtt.scratch_pt[type].page_mfn)
+		return;
+
+	intel_gvt_hypervisor_dma_unmap_guest_page(vgpu, pfn << PAGE_SHIFT);
+}
+
 static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt)
 {
 	struct intel_vgpu *vgpu = spt->vgpu;
@@ -838,14 +855,12 @@  static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt)
 	if (atomic_dec_return(&spt->refcount) > 0)
 		return 0;
 
-	if (gtt_type_is_pte_pt(spt->shadow_page.type))
-		goto release;
-
 	for_each_present_shadow_entry(spt, &e, index) {
 		switch (e.type) {
 		case GTT_TYPE_PPGTT_PTE_4K_ENTRY:
 			gvt_vdbg_mm("invalidate 4K entry\n");
-			continue;
+			ppgtt_invalidate_pte(spt, &e);
+			break;
 		case GTT_TYPE_PPGTT_PTE_2M_ENTRY:
 		case GTT_TYPE_PPGTT_PTE_1G_ENTRY:
 			WARN(1, "GVT doesn't support 2M/1GB page\n");
@@ -863,7 +878,7 @@  static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt)
 			GEM_BUG_ON(1);
 		}
 	}
-release:
+
 	trace_spt_change(spt->vgpu->id, "release", spt,
 			 spt->guest_page.gfn, spt->shadow_page.type);
 	ppgtt_free_spt(spt);
@@ -932,7 +947,9 @@  static int ppgtt_populate_shadow_entry(struct intel_vgpu *vgpu,
 {
 	struct intel_gvt_gtt_pte_ops *pte_ops = vgpu->gvt->gtt.pte_ops;
 	struct intel_gvt_gtt_entry se = *ge;
-	unsigned long gfn, mfn;
+	unsigned long gfn;
+	dma_addr_t dma_addr;
+	int ret;
 
 	if (!pte_ops->test_present(ge))
 		return 0;
@@ -952,11 +969,11 @@  static int ppgtt_populate_shadow_entry(struct intel_vgpu *vgpu,
 	};
 
 	/* direct shadow */
-	mfn = intel_gvt_hypervisor_gfn_to_mfn(vgpu, gfn);
-	if (mfn == INTEL_GVT_INVALID_ADDR)
+	ret = intel_gvt_hypervisor_dma_map_guest_page(vgpu, gfn, &dma_addr);
+	if (ret)
 		return -ENXIO;
 
-	pte_ops->set_pfn(&se, mfn);
+	pte_ops->set_pfn(&se, dma_addr >> PAGE_SHIFT);
 	ppgtt_set_shadow_entry(spt, &se, index);
 	return 0;
 }
@@ -1035,7 +1052,9 @@  static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_ppgtt_spt *spt,
 		ret = ppgtt_invalidate_spt(s);
 		if (ret)
 			goto fail;
-	}
+	} else
+		ppgtt_invalidate_pte(spt, se);
+
 	return 0;
 fail:
 	gvt_vgpu_err("fail: shadow page %p guest entry 0x%llx type %d\n",
@@ -1807,8 +1826,10 @@  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, mfn;
+	unsigned long gma, gfn;
 	struct intel_gvt_gtt_entry e, m;
+	dma_addr_t dma_addr;
+	int ret;
 
 	if (bytes != 4 && bytes != 8)
 		return -EINVAL;
@@ -1836,8 +1857,9 @@  static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
 			goto out;
 		}
 
-		mfn = intel_gvt_hypervisor_gfn_to_mfn(vgpu, gfn);
-		if (mfn == INTEL_GVT_INVALID_ADDR) {
+		ret = intel_gvt_hypervisor_dma_map_guest_page(vgpu, gfn,
+							      &dma_addr);
+		if (ret) {
 			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
@@ -1845,7 +1867,7 @@  static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
 			 */
 			ops->set_pfn(&m, gvt->gtt.scratch_mfn);
 		} else
-			ops->set_pfn(&m, mfn);
+			ops->set_pfn(&m, dma_addr >> PAGE_SHIFT);
 	} else
 		ops->set_pfn(&m, gvt->gtt.scratch_mfn);
 
diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 9131638..97d574a 100644
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -203,8 +203,15 @@  struct intel_vgpu {
 		int num_regions;
 		struct eventfd_ctx *intx_trigger;
 		struct eventfd_ctx *msi_trigger;
-		struct rb_root cache;
+
+		/*
+		 * Two caches are used to avoid mapping duplicated pages (eg.
+		 * scratch pages). This help to reduce dma setup overhead.
+		 */
+		struct rb_root gfn_cache;
+		struct rb_root dma_addr_cache;
 		struct mutex cache_lock;
+
 		struct notifier_block iommu_notifier;
 		struct notifier_block group_notifier;
 		struct kvm *kvm;
diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index cb6303e..f6dd9f7 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -51,6 +51,11 @@  struct intel_gvt_mpt {
 	int (*write_gpa)(unsigned long handle, unsigned long gpa, void *buf,
 			 unsigned long len);
 	unsigned long (*gfn_to_mfn)(unsigned long handle, unsigned long gfn);
+
+	int (*dma_map_guest_page)(unsigned long handle, unsigned long gfn,
+				  dma_addr_t *dma_addr);
+	void (*dma_unmap_guest_page)(unsigned long handle, dma_addr_t dma_addr);
+
 	int (*map_gfn_to_mfn)(unsigned long handle, unsigned long gfn,
 			      unsigned long mfn, unsigned int nr, bool map);
 	int (*set_trap_area)(unsigned long handle, u64 start, u64 end,
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 183cabb..6cb49c3 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -87,9 +87,12 @@  struct kvmgt_guest_info {
 };
 
 struct gvt_dma {
-	struct rb_node node;
+	struct intel_vgpu *vgpu;
+	struct rb_node gfn_node;
+	struct rb_node dma_addr_node;
 	gfn_t gfn;
-	unsigned long iova;
+	dma_addr_t dma_addr;
+	struct kref ref;
 };
 
 static inline bool handle_valid(unsigned long handle)
@@ -101,165 +104,163 @@  static int kvmgt_guest_init(struct mdev_device *mdev);
 static void intel_vgpu_release_work(struct work_struct *work);
 static bool kvmgt_guest_exit(struct kvmgt_guest_info *info);
 
-static int gvt_dma_map_iova(struct intel_vgpu *vgpu, kvm_pfn_t pfn,
-		unsigned long *iova)
+static int gvt_dma_map_page(struct intel_vgpu *vgpu, unsigned long gfn,
+		dma_addr_t *dma_addr)
 {
-	struct page *page;
 	struct device *dev = &vgpu->gvt->dev_priv->drm.pdev->dev;
-	dma_addr_t daddr;
+	struct page *page;
+	unsigned long pfn;
+	int ret;
 
-	if (unlikely(!pfn_valid(pfn)))
-		return -EFAULT;
+	/* Pin the page first. */
+	ret = vfio_pin_pages(mdev_dev(vgpu->vdev.mdev), &gfn, 1,
+			     IOMMU_READ | IOMMU_WRITE, &pfn);
+	if (ret != 1) {
+		gvt_vgpu_err("vfio_pin_pages failed for gfn 0x%lx: %d\n",
+			     gfn, ret);
+		return -EINVAL;
+	}
 
+	/* Setup DMA mapping. */
 	page = pfn_to_page(pfn);
-	daddr = dma_map_page(dev, page, 0, PAGE_SIZE,
-			PCI_DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(dev, daddr))
+	*dma_addr = dma_map_page(dev, page, 0, PAGE_SIZE,
+				 PCI_DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(dev, *dma_addr)) {
+		gvt_vgpu_err("DMA mapping failed for gfn 0x%lx\n", gfn);
+		vfio_unpin_pages(mdev_dev(vgpu->vdev.mdev), &gfn, 1);
 		return -ENOMEM;
+	}
 
-	*iova = (unsigned long)(daddr >> PAGE_SHIFT);
 	return 0;
 }
 
-static void gvt_dma_unmap_iova(struct intel_vgpu *vgpu, unsigned long iova)
+static void gvt_dma_unmap_page(struct intel_vgpu *vgpu, unsigned long gfn,
+		dma_addr_t dma_addr)
 {
 	struct device *dev = &vgpu->gvt->dev_priv->drm.pdev->dev;
-	dma_addr_t daddr;
+	int ret;
 
-	daddr = (dma_addr_t)(iova << PAGE_SHIFT);
-	dma_unmap_page(dev, daddr, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+	dma_unmap_page(dev, dma_addr, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+	ret = vfio_unpin_pages(mdev_dev(vgpu->vdev.mdev), &gfn, 1);
+	WARN_ON(ret != 1);
 }
 
-static struct gvt_dma *__gvt_cache_find(struct intel_vgpu *vgpu, gfn_t gfn)
+static struct gvt_dma *__gvt_cache_find_dma_addr(struct intel_vgpu *vgpu,
+		dma_addr_t dma_addr)
 {
-	struct rb_node *node = vgpu->vdev.cache.rb_node;
-	struct gvt_dma *ret = NULL;
+	struct rb_node *node = vgpu->vdev.dma_addr_cache.rb_node;
+	struct gvt_dma *itr;
 
 	while (node) {
-		struct gvt_dma *itr = rb_entry(node, struct gvt_dma, node);
+		itr = rb_entry(node, struct gvt_dma, dma_addr_node);
 
-		if (gfn < itr->gfn)
+		if (dma_addr < itr->dma_addr)
 			node = node->rb_left;
-		else if (gfn > itr->gfn)
+		else if (dma_addr > itr->dma_addr)
 			node = node->rb_right;
-		else {
-			ret = itr;
-			goto out;
-		}
+		else
+			return itr;
 	}
-
-out:
-	return ret;
+	return NULL;
 }
 
-static unsigned long gvt_cache_find(struct intel_vgpu *vgpu, gfn_t gfn)
+static struct gvt_dma *__gvt_cache_find_gfn(struct intel_vgpu *vgpu, gfn_t gfn)
 {
-	struct gvt_dma *entry;
-	unsigned long iova;
+	struct rb_node *node = vgpu->vdev.gfn_cache.rb_node;
+	struct gvt_dma *itr;
 
-	mutex_lock(&vgpu->vdev.cache_lock);
-
-	entry = __gvt_cache_find(vgpu, gfn);
-	iova = (entry == NULL) ? INTEL_GVT_INVALID_ADDR : entry->iova;
+	while (node) {
+		itr = rb_entry(node, struct gvt_dma, gfn_node);
 
-	mutex_unlock(&vgpu->vdev.cache_lock);
-	return iova;
+		if (gfn < itr->gfn)
+			node = node->rb_left;
+		else if (gfn > itr->gfn)
+			node = node->rb_right;
+		else
+			return itr;
+	}
+	return NULL;
 }
 
-static void gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn,
-		unsigned long iova)
+static void __gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn,
+		dma_addr_t dma_addr)
 {
 	struct gvt_dma *new, *itr;
-	struct rb_node **link = &vgpu->vdev.cache.rb_node, *parent = NULL;
+	struct rb_node **link, *parent = NULL;
 
 	new = kzalloc(sizeof(struct gvt_dma), GFP_KERNEL);
 	if (!new)
 		return;
 
+	new->vgpu = vgpu;
 	new->gfn = gfn;
-	new->iova = iova;
+	new->dma_addr = dma_addr;
+	kref_init(&new->ref);
 
-	mutex_lock(&vgpu->vdev.cache_lock);
+	/* gfn_cache maps gfn to struct gvt_dma. */
+	link = &vgpu->vdev.gfn_cache.rb_node;
 	while (*link) {
 		parent = *link;
-		itr = rb_entry(parent, struct gvt_dma, node);
+		itr = rb_entry(parent, struct gvt_dma, gfn_node);
 
-		if (gfn == itr->gfn)
-			goto out;
-		else if (gfn < itr->gfn)
+		if (gfn < itr->gfn)
 			link = &parent->rb_left;
 		else
 			link = &parent->rb_right;
 	}
+	rb_link_node(&new->gfn_node, parent, link);
+	rb_insert_color(&new->gfn_node, &vgpu->vdev.gfn_cache);
 
-	rb_link_node(&new->node, parent, link);
-	rb_insert_color(&new->node, &vgpu->vdev.cache);
-	mutex_unlock(&vgpu->vdev.cache_lock);
-	return;
+	/* dma_addr_cache maps dma addr to struct gvt_dma. */
+	parent = NULL;
+	link = &vgpu->vdev.dma_addr_cache.rb_node;
+	while (*link) {
+		parent = *link;
+		itr = rb_entry(parent, struct gvt_dma, dma_addr_node);
 
-out:
-	mutex_unlock(&vgpu->vdev.cache_lock);
-	kfree(new);
+		if (dma_addr < itr->dma_addr)
+			link = &parent->rb_left;
+		else
+			link = &parent->rb_right;
+	}
+	rb_link_node(&new->dma_addr_node, parent, link);
+	rb_insert_color(&new->dma_addr_node, &vgpu->vdev.dma_addr_cache);
 }
 
 static void __gvt_cache_remove_entry(struct intel_vgpu *vgpu,
 				struct gvt_dma *entry)
 {
-	rb_erase(&entry->node, &vgpu->vdev.cache);
+	rb_erase(&entry->gfn_node, &vgpu->vdev.gfn_cache);
+	rb_erase(&entry->dma_addr_node, &vgpu->vdev.dma_addr_cache);
 	kfree(entry);
 }
 
-static void gvt_cache_remove(struct intel_vgpu *vgpu, gfn_t gfn)
-{
-	struct device *dev = mdev_dev(vgpu->vdev.mdev);
-	struct gvt_dma *this;
-	unsigned long g1;
-	int rc;
-
-	mutex_lock(&vgpu->vdev.cache_lock);
-	this  = __gvt_cache_find(vgpu, gfn);
-	if (!this) {
-		mutex_unlock(&vgpu->vdev.cache_lock);
-		return;
-	}
-
-	g1 = gfn;
-	gvt_dma_unmap_iova(vgpu, this->iova);
-	rc = vfio_unpin_pages(dev, &g1, 1);
-	WARN_ON(rc != 1);
-	__gvt_cache_remove_entry(vgpu, this);
-	mutex_unlock(&vgpu->vdev.cache_lock);
-}
-
-static void gvt_cache_init(struct intel_vgpu *vgpu)
-{
-	vgpu->vdev.cache = RB_ROOT;
-	mutex_init(&vgpu->vdev.cache_lock);
-}
-
 static void gvt_cache_destroy(struct intel_vgpu *vgpu)
 {
 	struct gvt_dma *dma;
 	struct rb_node *node = NULL;
-	struct device *dev = mdev_dev(vgpu->vdev.mdev);
-	unsigned long gfn;
 
 	for (;;) {
 		mutex_lock(&vgpu->vdev.cache_lock);
-		node = rb_first(&vgpu->vdev.cache);
+		node = rb_first(&vgpu->vdev.gfn_cache);
 		if (!node) {
 			mutex_unlock(&vgpu->vdev.cache_lock);
 			break;
 		}
-		dma = rb_entry(node, struct gvt_dma, node);
-		gvt_dma_unmap_iova(vgpu, dma->iova);
-		gfn = dma->gfn;
+		dma = rb_entry(node, struct gvt_dma, gfn_node);
+		gvt_dma_unmap_page(vgpu, dma->gfn, dma->dma_addr);
 		__gvt_cache_remove_entry(vgpu, dma);
 		mutex_unlock(&vgpu->vdev.cache_lock);
-		vfio_unpin_pages(dev, &gfn, 1);
 	}
 }
 
+static void gvt_cache_init(struct intel_vgpu *vgpu)
+{
+	vgpu->vdev.gfn_cache = RB_ROOT;
+	vgpu->vdev.dma_addr_cache = RB_ROOT;
+	mutex_init(&vgpu->vdev.cache_lock);
+}
+
 static void kvmgt_protect_table_init(struct kvmgt_guest_info *info)
 {
 	hash_init(info->ptable);
@@ -489,13 +490,22 @@  static int intel_vgpu_iommu_notifier(struct notifier_block *nb,
 
 	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
 		struct vfio_iommu_type1_dma_unmap *unmap = data;
-		unsigned long gfn, end_gfn;
+		struct gvt_dma *entry;
+		unsigned long iov_pfn, end_iov_pfn;
+
+		iov_pfn = unmap->iova >> PAGE_SHIFT;
+		end_iov_pfn = iov_pfn + unmap->size / PAGE_SIZE;
 
-		gfn = unmap->iova >> PAGE_SHIFT;
-		end_gfn = gfn + unmap->size / PAGE_SIZE;
+		mutex_lock(&vgpu->vdev.cache_lock);
+		for (; iov_pfn < end_iov_pfn; iov_pfn++) {
+			entry = __gvt_cache_find_gfn(vgpu, iov_pfn);
+			if (!entry)
+				continue;
 
-		while (gfn < end_gfn)
-			gvt_cache_remove(vgpu, gfn++);
+			gvt_dma_unmap_page(vgpu, entry->gfn, entry->dma_addr);
+			__gvt_cache_remove_entry(vgpu, entry);
+		}
+		mutex_unlock(&vgpu->vdev.cache_lock);
 	}
 
 	return NOTIFY_OK;
@@ -1574,39 +1584,77 @@  static int kvmgt_inject_msi(unsigned long handle, u32 addr, u16 data)
 
 static unsigned long kvmgt_gfn_to_pfn(unsigned long handle, unsigned long gfn)
 {
-	unsigned long iova, pfn;
 	struct kvmgt_guest_info *info;
-	struct device *dev;
-	struct intel_vgpu *vgpu;
-	int rc;
+	kvm_pfn_t pfn;
 
 	if (!handle_valid(handle))
 		return INTEL_GVT_INVALID_ADDR;
 
 	info = (struct kvmgt_guest_info *)handle;
-	vgpu = info->vgpu;
-	iova = gvt_cache_find(info->vgpu, gfn);
-	if (iova != INTEL_GVT_INVALID_ADDR)
-		return iova;
-
-	pfn = INTEL_GVT_INVALID_ADDR;
-	dev = mdev_dev(info->vgpu->vdev.mdev);
-	rc = vfio_pin_pages(dev, &gfn, 1, IOMMU_READ | IOMMU_WRITE, &pfn);
-	if (rc != 1) {
-		gvt_vgpu_err("vfio_pin_pages failed for gfn 0x%lx: %d\n",
-			gfn, rc);
-		return INTEL_GVT_INVALID_ADDR;
-	}
-	/* transfer to host iova for GFX to use DMA */
-	rc = gvt_dma_map_iova(info->vgpu, pfn, &iova);
-	if (rc) {
-		gvt_vgpu_err("gvt_dma_map_iova failed for gfn: 0x%lx\n", gfn);
-		vfio_unpin_pages(dev, &gfn, 1);
+
+	pfn = gfn_to_pfn(info->kvm, gfn);
+	if (is_error_noslot_pfn(pfn))
 		return INTEL_GVT_INVALID_ADDR;
+
+	return pfn;
+}
+
+int kvmgt_dma_map_guest_page(unsigned long handle, unsigned long gfn,
+		dma_addr_t *dma_addr)
+{
+	struct kvmgt_guest_info *info;
+	struct intel_vgpu *vgpu;
+	struct gvt_dma *entry;
+	int ret;
+
+	if (!handle_valid(handle))
+		return -EINVAL;
+
+	info = (struct kvmgt_guest_info *)handle;
+	vgpu = info->vgpu;
+
+	mutex_lock(&info->vgpu->vdev.cache_lock);
+
+	entry = __gvt_cache_find_gfn(info->vgpu, gfn);
+	if (!entry) {
+		ret = gvt_dma_map_page(vgpu, gfn, dma_addr);
+		if (ret) {
+			mutex_unlock(&info->vgpu->vdev.cache_lock);
+			return ret;
+		}
+		__gvt_cache_add(info->vgpu, gfn, *dma_addr);
+	} else {
+		kref_get(&entry->ref);
+		*dma_addr = entry->dma_addr;
 	}
 
-	gvt_cache_add(info->vgpu, gfn, iova);
-	return iova;
+	mutex_unlock(&info->vgpu->vdev.cache_lock);
+	return 0;
+}
+
+static void __gvt_dma_release(struct kref *ref)
+{
+	struct gvt_dma *entry = container_of(ref, typeof(*entry), ref);
+
+	gvt_dma_unmap_page(entry->vgpu, entry->gfn, entry->dma_addr);
+	__gvt_cache_remove_entry(entry->vgpu, entry);
+}
+
+void kvmgt_dma_unmap_guest_page(unsigned long handle, dma_addr_t dma_addr)
+{
+	struct kvmgt_guest_info *info;
+	struct gvt_dma *entry;
+
+	if (!handle_valid(handle))
+		return;
+
+	info = (struct kvmgt_guest_info *)handle;
+
+	mutex_lock(&info->vgpu->vdev.cache_lock);
+	entry = __gvt_cache_find_dma_addr(info->vgpu, dma_addr);
+	if (entry)
+		kref_put(&entry->ref, __gvt_dma_release);
+	mutex_unlock(&info->vgpu->vdev.cache_lock);
 }
 
 static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa,
@@ -1681,6 +1729,8 @@  struct intel_gvt_mpt kvmgt_mpt = {
 	.read_gpa = kvmgt_read_gpa,
 	.write_gpa = kvmgt_write_gpa,
 	.gfn_to_mfn = kvmgt_gfn_to_pfn,
+	.dma_map_guest_page = kvmgt_dma_map_guest_page,
+	.dma_unmap_guest_page = kvmgt_dma_unmap_guest_page,
 	.set_opregion = kvmgt_set_opregion,
 	.get_vfio_device = kvmgt_get_vfio_device,
 	.put_vfio_device = kvmgt_put_vfio_device,
diff --git a/drivers/gpu/drm/i915/gvt/mpt.h b/drivers/gpu/drm/i915/gvt/mpt.h
index 78fada9..32ffcd5 100644
--- a/drivers/gpu/drm/i915/gvt/mpt.h
+++ b/drivers/gpu/drm/i915/gvt/mpt.h
@@ -228,6 +228,34 @@  static inline unsigned long intel_gvt_hypervisor_gfn_to_mfn(
 }
 
 /**
+ * intel_gvt_hypervisor_dma_map_guest_page - setup dma map for guest page
+ * @vgpu: a vGPU
+ * @gpfn: guest pfn
+ * @dma_addr: retrieve allocated dma addr
+ *
+ * Returns:
+ * 0 on success, negative error code if failed.
+ */
+static inline int intel_gvt_hypervisor_dma_map_guest_page(
+		struct intel_vgpu *vgpu, unsigned long gfn,
+		dma_addr_t *dma_addr)
+{
+	return intel_gvt_host.mpt->dma_map_guest_page(vgpu->handle, gfn,
+						      dma_addr);
+}
+
+/**
+ * intel_gvt_hypervisor_dma_unmap_guest_page - cancel dma map for guest page
+ * @vgpu: a vGPU
+ * @dma_addr: the mapped dma addr
+ */
+static inline void intel_gvt_hypervisor_dma_unmap_guest_page(
+		struct intel_vgpu *vgpu, dma_addr_t dma_addr)
+{
+	intel_gvt_host.mpt->dma_unmap_guest_page(vgpu->handle, dma_addr);
+}
+
+/**
  * intel_gvt_hypervisor_map_gfn_to_mfn - map a GFN region to MFN
  * @vgpu: a vGPU
  * @gfn: guest PFN