vfio/pci: Replace uses of vfio_device_data() with container_of

This tidies a few confused places that think they can have a refcount on
the vfio_device but the device_data could be NULL, that isn't possible by
design.

Most of the change falls out when struct vfio_devices is updated to just
store the struct vfio_pci_device itself. This wasn't possible before
because there was no easy way to get from the 'struct vfio_pci_device' to
the 'struct vfio_device' to put back the refcount.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Message-Id: <13-v3-225de1400dfc+4e074-vfio1_jgg@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 5f1a782..1f70387 100644 (file)
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -517,30 +517,29 @@ out:
 
 static struct pci_driver vfio_pci_driver;
 
-static struct vfio_pci_device *get_pf_vdev(struct vfio_pci_device *vdev,
-                                          struct vfio_device **pf_dev)
+static struct vfio_pci_device *get_pf_vdev(struct vfio_pci_device *vdev)
 {
        struct pci_dev *physfn = pci_physfn(vdev->pdev);
+       struct vfio_device *pf_dev;
 
        if (!vdev->pdev->is_virtfn)
                return NULL;
 
-       *pf_dev = vfio_device_get_from_dev(&physfn->dev);
-       if (!*pf_dev)
+       pf_dev = vfio_device_get_from_dev(&physfn->dev);
+       if (!pf_dev)
                return NULL;
 
        if (pci_dev_driver(physfn) != &vfio_pci_driver) {
-               vfio_device_put(*pf_dev);
+               vfio_device_put(pf_dev);
                return NULL;
        }
 
-       return vfio_device_data(*pf_dev);
+       return container_of(pf_dev, struct vfio_pci_device, vdev);
 }
 
 static void vfio_pci_vf_token_user_add(struct vfio_pci_device *vdev, int val)
 {
-       struct vfio_device *pf_dev;
-       struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev);
+       struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev);
 
        if (!pf_vdev)
                return;
@@ -550,7 +549,7 @@ static void vfio_pci_vf_token_user_add(struct vfio_pci_device *vdev, int val)
        WARN_ON(pf_vdev->vf_token->users < 0);
        mutex_unlock(&pf_vdev->vf_token->lock);
 
-       vfio_device_put(pf_dev);
+       vfio_device_put(&pf_vdev->vdev);
 }
 
 static void vfio_pci_release(struct vfio_device *core_vdev)
@@ -794,7 +793,7 @@ int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
 }
 
 struct vfio_devices {
-       struct vfio_device **devices;
+       struct vfio_pci_device **devices;
        int cur_index;
        int max_index;
 };
@@ -1283,9 +1282,7 @@ reset_info_exit:
                        goto hot_reset_release;
 
                for (; mem_idx < devs.cur_index; mem_idx++) {
-                       struct vfio_pci_device *tmp;
-
-                       tmp = vfio_device_data(devs.devices[mem_idx]);
+                       struct vfio_pci_device *tmp = devs.devices[mem_idx];
 
                        ret = down_write_trylock(&tmp->memory_lock);
                        if (!ret) {
@@ -1300,17 +1297,13 @@ reset_info_exit:
 
 hot_reset_release:
                for (i = 0; i < devs.cur_index; i++) {
-                       struct vfio_device *device;
-                       struct vfio_pci_device *tmp;
-
-                       device = devs.devices[i];
-                       tmp = vfio_device_data(device);
+                       struct vfio_pci_device *tmp = devs.devices[i];
 
                        if (i < mem_idx)
                                up_write(&tmp->memory_lock);
                        else
                                mutex_unlock(&tmp->vma_lock);
-                       vfio_device_put(device);
+                       vfio_device_put(&tmp->vdev);
                }
                kfree(devs.devices);
 
@@ -1777,8 +1770,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_device *vdev,
                return 0; /* No VF token provided or required */
 
        if (vdev->pdev->is_virtfn) {
-               struct vfio_device *pf_dev;
-               struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev);
+               struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev);
                bool match;
 
                if (!pf_vdev) {
@@ -1791,7 +1783,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_device *vdev,
                }
 
                if (!vf_token) {
-                       vfio_device_put(pf_dev);
+                       vfio_device_put(&pf_vdev->vdev);
                        pci_info_ratelimited(vdev->pdev,
                                "VF token required to access device\n");
                        return -EACCES;
@@ -1801,7 +1793,7 @@ static int vfio_pci_validate_vf_token(struct vfio_pci_device *vdev,
                match = uuid_equal(uuid, &pf_vdev->vf_token->uuid);
                mutex_unlock(&pf_vdev->vf_token->lock);
 
-               vfio_device_put(pf_dev);
+               vfio_device_put(&pf_vdev->vdev);
 
                if (!match) {
                        pci_info_ratelimited(vdev->pdev,
@@ -2122,11 +2114,7 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
        if (device == NULL)
                return PCI_ERS_RESULT_DISCONNECT;
 
-       vdev = vfio_device_data(device);
-       if (vdev == NULL) {
-               vfio_device_put(device);
-               return PCI_ERS_RESULT_DISCONNECT;
-       }
+       vdev = container_of(device, struct vfio_pci_device, vdev);
 
        mutex_lock(&vdev->igate);
 
@@ -2142,7 +2130,6 @@ static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
 
 static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
 {
-       struct vfio_pci_device *vdev;
        struct vfio_device *device;
        int ret = 0;
 
@@ -2155,12 +2142,6 @@ static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
        if (!device)
                return -ENODEV;
 
-       vdev = vfio_device_data(device);
-       if (!vdev) {
-               vfio_device_put(device);
-               return -ENODEV;
-       }
-
        if (nr_virtfn == 0)
                pci_disable_sriov(pdev);
        else
@@ -2220,7 +2201,7 @@ static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data)
                return 0;
        }
 
-       vdev = vfio_device_data(device);
+       vdev = container_of(device, struct vfio_pci_device, vdev);
 
        if (vdev->reflck) {
                vfio_pci_reflck_get(vdev->reflck);
@@ -2282,7 +2263,7 @@ static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
                return -EBUSY;
        }
 
-       vdev = vfio_device_data(device);
+       vdev = container_of(device, struct vfio_pci_device, vdev);
 
        /* Fault if the device is not unused */
        if (vdev->refcnt) {
@@ -2290,7 +2271,7 @@ static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
                return -EBUSY;
        }
 
-       devs->devices[devs->cur_index++] = device;
+       devs->devices[devs->cur_index++] = vdev;
        return 0;
 }
 
@@ -2312,7 +2293,7 @@ static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data)
                return -EBUSY;
        }
 
-       vdev = vfio_device_data(device);
+       vdev = container_of(device, struct vfio_pci_device, vdev);
 
        /*
         * Locking multiple devices is prone to deadlock, runaway and
@@ -2323,7 +2304,7 @@ static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data)
                return -EBUSY;
        }
 
-       devs->devices[devs->cur_index++] = device;
+       devs->devices[devs->cur_index++] = vdev;
        return 0;
 }
 
@@ -2371,7 +2352,7 @@ static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
 
        /* Does at least one need a reset? */
        for (i = 0; i < devs.cur_index; i++) {
-               tmp = vfio_device_data(devs.devices[i]);
+               tmp = devs.devices[i];
                if (tmp->needs_reset) {
                        ret = pci_reset_bus(vdev->pdev);
                        break;
@@ -2380,7 +2361,7 @@ static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
 
 put_devs:
        for (i = 0; i < devs.cur_index; i++) {
-               tmp = vfio_device_data(devs.devices[i]);
+               tmp = devs.devices[i];
 
                /*
                 * If reset was successful, affected devices no longer need
@@ -2396,7 +2377,7 @@ put_devs:
                                vfio_pci_set_power_state(tmp, PCI_D3hot);
                }
 
-               vfio_device_put(devs.devices[i]);
+               vfio_device_put(&tmp->vdev);
        }
 
        kfree(devs.devices);