[PATCH 5/9] vfio/pci: introduce vfio_pci_device structure

Max Gurtovoy
2021-03-09T08:35:23Z

This structure will hold the specific attributes for the generic
vfio_pci.ko driver. It will be allocated by the vfio_pci driver that
will register the vfio subsystem using vfio_pci_core_register_device
and it will unregister the using vfio_pci_core_unregister_device. In
this way every vfio_pci future driver will be able to use this mechanism
to set vendor specific attributes in its vendor specific structure and
register to subsystem core while utilizing vfio_pci_core library.

This is a standard Linux subsystem behaviour and will also ease on
vfio_pci drivers to extend callbacks of vfio_device_ops and will be able
to use container_of mechanism as well (instead of passing void pointers
as around the stack).

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
---
drivers/vfio/pci/vfio_pci.c | 31 +++++++++++++++++++++----
drivers/vfio/pci/vfio_pci_core.c | 39 +++++++++++++-------------------
drivers/vfio/pci/vfio_pci_core.h | 5 ++--
3 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 447c31f4e64e..dbc0a6559914 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -19,6 +19,7 @@
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/list.h>
#include <linux/notifier.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
@@ -31,6 +32,10 @@
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
#define DRIVER_DESC "VFIO PCI - User Level meta-driver"

+struct vfio_pci_device {
+ struct vfio_pci_core_device vdev;
+};
+
static char ids[1024] __initdata;
module_param_string(ids, ids, sizeof(ids), 0);
MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified");
@@ -139,21 +144,37 @@ static const struct vfio_device_ops vfio_pci_ops = {

static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
- struct vfio_pci_core_device *vdev;
+ struct vfio_pci_device *vpdev;
+ int ret;

if (vfio_pci_is_denylisted(pdev))
return -EINVAL;

- vdev = vfio_create_pci_device(pdev, &vfio_pci_ops);
- if (IS_ERR(vdev))
- return PTR_ERR(vdev);
+ vpdev = kzalloc(sizeof(*vpdev), GFP_KERNEL);
+ if (!vpdev)
+ return -ENOMEM;
+
+ ret = vfio_pci_core_register_device(&vpdev->vdev, pdev, &vfio_pci_ops);
+ if (ret)
+ goto out_free;

return 0;
+
+out_free:
+ kfree(vpdev);
+ return ret;
}

static void vfio_pci_remove(struct pci_dev *pdev)
{
- vfio_destroy_pci_device(pdev);
+ struct vfio_device *vdev = dev_get_drvdata(&pdev->dev);
+ struct vfio_pci_core_device *core_vpdev = vfio_device_data(vdev);
+ struct vfio_pci_device *vpdev;
+
+ vpdev = container_of(core_vpdev, struct vfio_pci_device, vdev);
+
+ vfio_pci_core_unregister_device(core_vpdev);
+ kfree(vpdev);
}

static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 878a3609b916..7b6be1e4646f 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1837,15 +1837,15 @@ static int vfio_pci_bus_notifier(struct notifier_block *nb,
return 0;
}

-struct vfio_pci_core_device *vfio_create_pci_device(struct pci_dev *pdev,
+int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev,
+ struct pci_dev *pdev,
const struct vfio_device_ops *vfio_pci_ops)
{
- struct vfio_pci_core_device *vdev;
struct iommu_group *group;
int ret;

if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
- return ERR_PTR(-EINVAL);
+ return -EINVAL;

/*
* Prevent binding to PFs with VFs enabled, the VFs might be in use
@@ -1857,18 +1857,12 @@ struct vfio_pci_core_device *vfio_create_pci_device(struct pci_dev *pdev,
*/
if (pci_num_vf(pdev)) {
pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
- return ERR_PTR(-EBUSY);
+ return -EBUSY;
}

group = vfio_iommu_group_get(&pdev->dev);
if (!group)
- return ERR_PTR(-EINVAL);
-
- vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
- if (!vdev) {
- ret = -ENOMEM;
- goto out_group_put;
- }
+ return -EINVAL;

vdev->pdev = pdev;
vdev->vfio_pci_ops = vfio_pci_ops;
@@ -1884,7 +1878,7 @@ struct vfio_pci_core_device *vfio_create_pci_device(struct pci_dev *pdev,

ret = vfio_add_group_dev(&pdev->dev, vfio_pci_ops, vdev);
if (ret)
- goto out_free;
+ goto out_group_put;

ret = vfio_pci_reflck_attach(vdev);
if (ret)
@@ -1928,7 +1922,7 @@ struct vfio_pci_core_device *vfio_create_pci_device(struct pci_dev *pdev,
vfio_pci_set_power_state(vdev, PCI_D3hot);
}

- return vdev;
+ return 0;

out_vf_token:
kfree(vdev->vf_token);
@@ -1936,22 +1930,22 @@ struct vfio_pci_core_device *vfio_create_pci_device(struct pci_dev *pdev,
vfio_pci_reflck_put(vdev->reflck);
out_del_group_dev:
vfio_del_group_dev(&pdev->dev);
-out_free:
- kfree(vdev);
out_group_put:
vfio_iommu_group_put(group, &pdev->dev);
- return ERR_PTR(ret);
+ return ret;
}
-EXPORT_SYMBOL_GPL(vfio_create_pci_device);
+EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);

-void vfio_destroy_pci_device(struct pci_dev *pdev)
+void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev)
{
- struct vfio_pci_core_device *vdev;
+ struct pci_dev *pdev;
+ struct vfio_pci_core_device *g_vdev;

+ pdev = vdev->pdev;
pci_disable_sriov(pdev);

- vdev = vfio_del_group_dev(&pdev->dev);
- if (!vdev)
+ g_vdev = vfio_del_group_dev(&pdev->dev);
+ if (g_vdev != vdev)
return;

if (vdev->vf_token) {
@@ -1973,7 +1967,6 @@ void vfio_destroy_pci_device(struct pci_dev *pdev)
vfio_pci_set_power_state(vdev, PCI_D0);

kfree(vdev->pm_save);
- kfree(vdev);

if (vfio_pci_is_vga(pdev)) {
vga_client_register(pdev, NULL, NULL, NULL);
@@ -1982,7 +1975,7 @@ void vfio_destroy_pci_device(struct pci_dev *pdev)
VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM);
}
}
-EXPORT_SYMBOL_GPL(vfio_destroy_pci_device);
+EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_device);

static pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev,
pci_channel_state_t state)
diff --git a/drivers/vfio/pci/vfio_pci_core.h b/drivers/vfio/pci/vfio_pci_core.h
index a3517a9472bd..46eb3443125b 100644
--- a/drivers/vfio/pci/vfio_pci_core.h
+++ b/drivers/vfio/pci/vfio_pci_core.h
@@ -231,9 +231,10 @@ static inline int vfio_pci_info_zdev_add_caps(struct vfio_pci_core_device *vdev,
#endif

/* Exported functions */
-struct vfio_pci_core_device *vfio_create_pci_device(struct pci_dev *pdev,
+int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev,
+ struct pci_dev *pdev,
const struct vfio_device_ops *vfio_pci_ops);
-void vfio_destroy_pci_device(struct pci_dev *pdev);
+void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev);

long vfio_pci_core_ioctl(void *device_data, unsigned int cmd,
unsigned long arg);
--
2.25.4