drm/i915/gvt: convert to use vfio_register_emulated_iommu_dev

This is straightforward conversion, the intel_vgpu already has a pointer
to the vfio_dev, which can be replaced with the embedded structure and
we can replace all the mdev_get_drvdata() with a simple container_of().

Based on an patch from Jason Gunthorpe.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20220411141403.86980-29-hch@lst.de
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Zhi Wang <zhi.a.wang@intel.com>

diff --git a/drivers/gpu/drm/i915/gvt/gvt.h b/drivers/gpu/drm/i915/gvt/gvt.h
index 8565189..c32e8eb 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/gvt.h
+++ b/drivers/gpu/drm/i915/gvt/gvt.h
@@ -211,7 +211,7 @@ struct intel_vgpu {
 
        u32 scan_nonprivbb;
 
-       struct mdev_device *mdev;
+       struct vfio_device vfio_device;
        struct vfio_region *region;
        int num_regions;
        struct eventfd_ctx *intx_trigger;

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 38629ab..4113f85 100644 (file)
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -100,6 +100,9 @@ struct gvt_dma {
        struct kref ref;
 };
 
+#define vfio_dev_to_vgpu(vfio_dev) \
+       container_of((vfio_dev), struct intel_vgpu, vfio_device)
+
 static void kvmgt_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                const u8 *val, int len,
                struct kvm_page_track_notifier_node *node);
@@ -723,44 +726,6 @@ int intel_gvt_set_edid(struct intel_vgpu *vgpu, int port_num)
        return ret;
 }
 
-static int intel_vgpu_create(struct mdev_device *mdev)
-{
-       struct device *pdev = mdev_parent_dev(mdev);
-       struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
-       struct intel_vgpu_type *type;
-       struct intel_vgpu *vgpu;
-
-       type = &gvt->types[mdev_get_type_group_id(mdev)];
-       if (!type)
-               return -EINVAL;
-
-       vgpu = intel_gvt_create_vgpu(gvt, type);
-       if (IS_ERR(vgpu)) {
-               gvt_err("failed to create intel vgpu: %ld\n", PTR_ERR(vgpu));
-               return PTR_ERR(vgpu);
-       }
-
-       INIT_WORK(&vgpu->release_work, intel_vgpu_release_work);
-
-       vgpu->mdev = mdev;
-       mdev_set_drvdata(mdev, vgpu);
-
-       gvt_dbg_core("intel_vgpu_create succeeded for mdev: %s\n",
-                    dev_name(mdev_dev(mdev)));
-       return 0;
-}
-
-static int intel_vgpu_remove(struct mdev_device *mdev)
-{
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
-
-       if (vgpu->attached)
-               return -EBUSY;
-
-       intel_gvt_destroy_vgpu(vgpu);
-       return 0;
-}
-
 static int intel_vgpu_iommu_notifier(struct notifier_block *nb,
                                     unsigned long action, void *data)
 {
@@ -829,9 +794,9 @@ out:
        return ret;
 }
 
-static int intel_vgpu_open_device(struct mdev_device *mdev)
+static int intel_vgpu_open_device(struct vfio_device *vfio_dev)
 {
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
+       struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
        unsigned long events;
        int ret;
        struct vfio_group *vfio_group;
@@ -840,7 +805,7 @@ static int intel_vgpu_open_device(struct mdev_device *mdev)
        vgpu->group_notifier.notifier_call = intel_vgpu_group_notifier;
 
        events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
-       ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY, &events,
+       ret = vfio_register_notifier(vfio_dev->dev, VFIO_IOMMU_NOTIFY, &events,
                                &vgpu->iommu_notifier);
        if (ret != 0) {
                gvt_vgpu_err("vfio_register_notifier for iommu failed: %d\n",
@@ -849,7 +814,7 @@ static int intel_vgpu_open_device(struct mdev_device *mdev)
        }
 
        events = VFIO_GROUP_NOTIFY_SET_KVM;
-       ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY, &events,
+       ret = vfio_register_notifier(vfio_dev->dev, VFIO_GROUP_NOTIFY, &events,
                                &vgpu->group_notifier);
        if (ret != 0) {
                gvt_vgpu_err("vfio_register_notifier for group failed: %d\n",
@@ -857,7 +822,8 @@ static int intel_vgpu_open_device(struct mdev_device *mdev)
                goto undo_iommu;
        }
 
-       vfio_group = vfio_group_get_external_user_from_dev(mdev_dev(mdev));
+       vfio_group =
+               vfio_group_get_external_user_from_dev(vgpu->vfio_device.dev);
        if (IS_ERR_OR_NULL(vfio_group)) {
                ret = !vfio_group ? -EFAULT : PTR_ERR(vfio_group);
                gvt_vgpu_err("vfio_group_get_external_user_from_dev failed\n");
@@ -865,14 +831,6 @@ static int intel_vgpu_open_device(struct mdev_device *mdev)
        }
        vgpu->vfio_group = vfio_group;
 
-       /* Take a module reference as mdev core doesn't take
-        * a reference for vendor driver.
-        */
-       if (!try_module_get(THIS_MODULE)) {
-               ret = -ENODEV;
-               goto undo_group;
-       }
-
        ret = -EEXIST;
        if (vgpu->attached)
                goto undo_group;
@@ -910,11 +868,11 @@ undo_group:
        vgpu->vfio_group = NULL;
 
 undo_register:
-       vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
+       vfio_unregister_notifier(vfio_dev->dev, VFIO_GROUP_NOTIFY,
                                        &vgpu->group_notifier);
 
 undo_iommu:
-       vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
+       vfio_unregister_notifier(vfio_dev->dev, VFIO_IOMMU_NOTIFY,
                                        &vgpu->iommu_notifier);
 out:
        return ret;
@@ -944,19 +902,16 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
 
        intel_gvt_release_vgpu(vgpu);
 
-       ret = vfio_unregister_notifier(mdev_dev(vgpu->mdev), VFIO_IOMMU_NOTIFY,
+       ret = vfio_unregister_notifier(vgpu->vfio_device.dev, VFIO_IOMMU_NOTIFY,
                                        &vgpu->iommu_notifier);
        drm_WARN(&i915->drm, ret,
                 "vfio_unregister_notifier for iommu failed: %d\n", ret);
 
-       ret = vfio_unregister_notifier(mdev_dev(vgpu->mdev), VFIO_GROUP_NOTIFY,
+       ret = vfio_unregister_notifier(vgpu->vfio_device.dev, VFIO_GROUP_NOTIFY,
                                        &vgpu->group_notifier);
        drm_WARN(&i915->drm, ret,
                 "vfio_unregister_notifier for group failed: %d\n", ret);
 
-       /* dereference module reference taken at open */
-       module_put(THIS_MODULE);
-
        debugfs_remove(debugfs_lookup(KVMGT_DEBUGFS_FILENAME, vgpu->debugfs));
 
        kvm_page_track_unregister_notifier(vgpu->kvm, &vgpu->track_node);
@@ -971,11 +926,9 @@ static void __intel_vgpu_release(struct intel_vgpu *vgpu)
        vgpu->attached = false;
 }
 
-static void intel_vgpu_close_device(struct mdev_device *mdev)
+static void intel_vgpu_close_device(struct vfio_device *vfio_dev)
 {
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
-
-       __intel_vgpu_release(vgpu);
+       __intel_vgpu_release(vfio_dev_to_vgpu(vfio_dev));
 }
 
 static void intel_vgpu_release_work(struct work_struct *work)
@@ -1127,10 +1080,10 @@ static bool gtt_entry(struct intel_vgpu *vgpu, loff_t *ppos)
                        true : false;
 }
 
-static ssize_t intel_vgpu_read(struct mdev_device *mdev, char __user *buf,
+static ssize_t intel_vgpu_read(struct vfio_device *vfio_dev, char __user *buf,
                        size_t count, loff_t *ppos)
 {
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
+       struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
        unsigned int done = 0;
        int ret;
 
@@ -1201,11 +1154,11 @@ read_err:
        return -EFAULT;
 }
 
-static ssize_t intel_vgpu_write(struct mdev_device *mdev,
+static ssize_t intel_vgpu_write(struct vfio_device *vfio_dev,
                                const char __user *buf,
                                size_t count, loff_t *ppos)
 {
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
+       struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
        unsigned int done = 0;
        int ret;
 
@@ -1275,13 +1228,14 @@ write_err:
        return -EFAULT;
 }
 
-static int intel_vgpu_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
+static int intel_vgpu_mmap(struct vfio_device *vfio_dev,
+               struct vm_area_struct *vma)
 {
+       struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
        unsigned int index;
        u64 virtaddr;
        unsigned long req_size, pgoff, req_start;
        pgprot_t pg_prot;
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
 
        index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
        if (index >= VFIO_PCI_ROM_REGION_INDEX)
@@ -1404,10 +1358,10 @@ static int intel_vgpu_set_irqs(struct intel_vgpu *vgpu, u32 flags,
        return func(vgpu, index, start, count, flags, data);
 }
 
-static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
+static long intel_vgpu_ioctl(struct vfio_device *vfio_dev, unsigned int cmd,
                             unsigned long arg)
 {
-       struct intel_vgpu *vgpu = mdev_get_drvdata(mdev);
+       struct intel_vgpu *vgpu = vfio_dev_to_vgpu(vfio_dev);
        unsigned long minsz;
 
        gvt_dbg_core("vgpu%d ioctl, cmd: %d\n", vgpu->id, cmd);
@@ -1682,14 +1636,9 @@ static ssize_t
 vgpu_id_show(struct device *dev, struct device_attribute *attr,
             char *buf)
 {
-       struct mdev_device *mdev = mdev_from_dev(dev);
+       struct intel_vgpu *vgpu = dev_get_drvdata(dev);
 
-       if (mdev) {
-               struct intel_vgpu *vgpu = (struct intel_vgpu *)
-                       mdev_get_drvdata(mdev);
-               return sprintf(buf, "%d\n", vgpu->id);
-       }
-       return sprintf(buf, "\n");
+       return sprintf(buf, "%d\n", vgpu->id);
 }
 
 static DEVICE_ATTR_RO(vgpu_id);
@@ -1709,19 +1658,72 @@ static const struct attribute_group *intel_vgpu_groups[] = {
        NULL,
 };
 
-const struct mdev_parent_ops intel_vgpu_mdev_ops = {
-       .mdev_attr_groups       = intel_vgpu_groups,
-       .supported_type_groups  = gvt_vgpu_type_groups,
-       .create                 = intel_vgpu_create,
-       .remove                 = intel_vgpu_remove,
+static const struct vfio_device_ops intel_vgpu_dev_ops = {
+       .open_device    = intel_vgpu_open_device,
+       .close_device   = intel_vgpu_close_device,
+       .read           = intel_vgpu_read,
+       .write          = intel_vgpu_write,
+       .mmap           = intel_vgpu_mmap,
+       .ioctl          = intel_vgpu_ioctl,
+};
 
-       .open_device            = intel_vgpu_open_device,
-       .close_device           = intel_vgpu_close_device,
+static int intel_vgpu_probe(struct mdev_device *mdev)
+{
+       struct device *pdev = mdev_parent_dev(mdev);
+       struct intel_gvt *gvt = kdev_to_i915(pdev)->gvt;
+       struct intel_vgpu_type *type;
+       struct intel_vgpu *vgpu;
+       int ret;
+
+       type = &gvt->types[mdev_get_type_group_id(mdev)];
+       if (!type)
+               return -EINVAL;
+
+       vgpu = intel_gvt_create_vgpu(gvt, type);
+       if (IS_ERR(vgpu)) {
+               gvt_err("failed to create intel vgpu: %ld\n", PTR_ERR(vgpu));
+               return PTR_ERR(vgpu);
+       }
 
-       .read                   = intel_vgpu_read,
-       .write                  = intel_vgpu_write,
-       .mmap                   = intel_vgpu_mmap,
-       .ioctl                  = intel_vgpu_ioctl,
+       INIT_WORK(&vgpu->release_work, intel_vgpu_release_work);
+       vfio_init_group_dev(&vgpu->vfio_device, &mdev->dev,
+                           &intel_vgpu_dev_ops);
+
+       dev_set_drvdata(&mdev->dev, vgpu);
+       ret = vfio_register_emulated_iommu_dev(&vgpu->vfio_device);
+       if (ret) {
+               intel_gvt_destroy_vgpu(vgpu);
+               return ret;
+       }
+
+       gvt_dbg_core("intel_vgpu_create succeeded for mdev: %s\n",
+                    dev_name(mdev_dev(mdev)));
+       return 0;
+}
+
+static void intel_vgpu_remove(struct mdev_device *mdev)
+{
+       struct intel_vgpu *vgpu = dev_get_drvdata(&mdev->dev);
+
+       if (WARN_ON_ONCE(vgpu->attached))
+               return;
+       intel_gvt_destroy_vgpu(vgpu);
+}
+
+static struct mdev_driver intel_vgpu_mdev_driver = {
+       .driver = {
+               .name           = "intel_vgpu_mdev",
+               .owner          = THIS_MODULE,
+               .dev_groups     = intel_vgpu_groups,
+       },
+       .probe          = intel_vgpu_probe,
+       .remove         = intel_vgpu_remove,
+};
+
+const struct mdev_parent_ops intel_vgpu_mdev_ops = {
+       .owner                  = THIS_MODULE,
+       .supported_type_groups  = gvt_vgpu_type_groups,
+       .device_driver          = &intel_vgpu_mdev_driver,
 };
 
 int intel_gvt_page_track_add(struct intel_vgpu *info, u64 gfn)
@@ -1925,11 +1927,21 @@ void intel_gvt_dma_unmap_guest_page(struct intel_vgpu *vgpu,
 
 static int __init kvmgt_init(void)
 {
-       return intel_gvt_set_ops(&intel_gvt_vgpu_ops);
+       int ret;
+
+       ret = intel_gvt_set_ops(&intel_gvt_vgpu_ops);
+       if (ret)
+               return ret;
+
+       ret = mdev_register_driver(&intel_vgpu_mdev_driver);
+       if (ret)
+               intel_gvt_clear_ops(&intel_gvt_vgpu_ops);
+       return ret;
 }
 
 static void __exit kvmgt_exit(void)
 {
+       mdev_unregister_driver(&intel_vgpu_mdev_driver);
        intel_gvt_clear_ops(&intel_gvt_vgpu_ops);
 }