drm/i915/gvt: map pfn for PTE entry in kvm

When host i915 iommu enabled, gvt needs to use a mapped pfn in PTE entry
So before kvm returns the pfn, map this pfn and return the mapped address
which is so called iova.

Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index b49a01d85dde84fbaf82638baaf6263cb53ca104..c429ed033fc49c4d96d9c9417d5caceb63f2360f 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -77,7 +77,7 @@ struct kvmgt_guest_info {
 struct gvt_dma {
        struct rb_node node;
        gfn_t gfn;
-       kvm_pfn_t pfn;
+       unsigned long iova;
 };
 
 static inline bool handle_valid(unsigned long handle)
@@ -89,6 +89,35 @@ 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)
+{
+       struct page *page;
+       struct device *dev = &vgpu->gvt->dev_priv->drm.pdev->dev;
+       dma_addr_t daddr;
+
+       page = pfn_to_page(pfn);
+       if (is_error_page(page))
+               return -EFAULT;
+
+       daddr = dma_map_page(dev, page, 0, PAGE_SIZE,
+                       PCI_DMA_BIDIRECTIONAL);
+       if (dma_mapping_error(dev, daddr))
+               return -ENOMEM;
+
+       *iova = (unsigned long)(daddr >> PAGE_SHIFT);
+       return 0;
+}
+
+static void gvt_dma_unmap_iova(struct intel_vgpu *vgpu, unsigned long iova)
+{
+       struct device *dev = &vgpu->gvt->dev_priv->drm.pdev->dev;
+       dma_addr_t daddr;
+
+       daddr = (dma_addr_t)(iova << PAGE_SHIFT);
+       dma_unmap_page(dev, daddr, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
+}
+
 static struct gvt_dma *__gvt_cache_find(struct intel_vgpu *vgpu, gfn_t gfn)
 {
        struct rb_node *node = vgpu->vdev.cache.rb_node;
@@ -111,21 +140,22 @@ out:
        return ret;
 }
 
-static kvm_pfn_t gvt_cache_find(struct intel_vgpu *vgpu, gfn_t gfn)
+static unsigned long gvt_cache_find(struct intel_vgpu *vgpu, gfn_t gfn)
 {
        struct gvt_dma *entry;
-       kvm_pfn_t pfn;
+       unsigned long iova;
 
        mutex_lock(&vgpu->vdev.cache_lock);
 
        entry = __gvt_cache_find(vgpu, gfn);
-       pfn = (entry == NULL) ? 0 : entry->pfn;
+       iova = (entry == NULL) ? INTEL_GVT_INVALID_ADDR : entry->iova;
 
        mutex_unlock(&vgpu->vdev.cache_lock);
-       return pfn;
+       return iova;
 }
 
-static void gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn, kvm_pfn_t pfn)
+static void gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn,
+               unsigned long iova)
 {
        struct gvt_dma *new, *itr;
        struct rb_node **link = &vgpu->vdev.cache.rb_node, *parent = NULL;
@@ -135,7 +165,7 @@ static void gvt_cache_add(struct intel_vgpu *vgpu, gfn_t gfn, kvm_pfn_t pfn)
                return;
 
        new->gfn = gfn;
-       new->pfn = pfn;
+       new->iova = iova;
 
        mutex_lock(&vgpu->vdev.cache_lock);
        while (*link) {
@@ -182,6 +212,7 @@ static void gvt_cache_remove(struct intel_vgpu *vgpu, gfn_t gfn)
        }
 
        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);
@@ -204,6 +235,7 @@ static void gvt_cache_destroy(struct intel_vgpu *vgpu)
        mutex_lock(&vgpu->vdev.cache_lock);
        while ((node = rb_first(&vgpu->vdev.cache))) {
                dma = rb_entry(node, struct gvt_dma, node);
+               gvt_dma_unmap_iova(vgpu, dma->iova);
                gfn = dma->gfn;
 
                vfio_unpin_pages(dev, &gfn, 1);
@@ -1348,7 +1380,7 @@ 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 pfn;
+       unsigned long iova, pfn;
        struct kvmgt_guest_info *info;
        struct device *dev;
        int rc;
@@ -1357,9 +1389,9 @@ static unsigned long kvmgt_gfn_to_pfn(unsigned long handle, unsigned long gfn)
                return INTEL_GVT_INVALID_ADDR;
 
        info = (struct kvmgt_guest_info *)handle;
-       pfn = gvt_cache_find(info->vgpu, gfn);
-       if (pfn != 0)
-               return pfn;
+       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);
@@ -1368,9 +1400,13 @@ static unsigned long kvmgt_gfn_to_pfn(unsigned long handle, unsigned long gfn)
                gvt_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_err("gvt_dma_map_iova failed for gfn: 0x%lx\n", gfn);
 
-       gvt_cache_add(info->vgpu, gfn, pfn);
-       return pfn;
+       gvt_cache_add(info->vgpu, gfn, iova);
+       return iova;
 }
 
 static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa,