[PATCH v3 3/7] vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages()

Jason Gunthorpe
2022-05-02T17:31:52Z

Every caller has a readily available vfio_device pointer, use that instead
of passing in a generic struct device. The struct vfio_device already
contains the group we need so this avoids complexity, extra refcountings,
and a confusing lifecycle model.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
.../driver-api/vfio-mediated-device.rst | 4 +-
drivers/s390/cio/vfio_ccw_cp.c | 6 +--
drivers/s390/crypto/vfio_ap_ops.c | 9 ++---
drivers/vfio/vfio.c | 40 ++++++-------------
include/linux/vfio.h | 4 +-
5 files changed, 24 insertions(+), 39 deletions(-)

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 784bbeb22adcf5..2f9e6025eb2fe1 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -262,10 +262,10 @@ Translation APIs for Mediated Devices
The following APIs are provided for translating user pfn to host pfn in a VFIO
driver::

- extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
+ int vfio_pin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
int npage, int prot, unsigned long *phys_pfn);

- extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
+ int vfio_unpin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
int npage);

These functions call back into the back-end IOMMU module by using the pin_pages
diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c
index 7a1cf3091cd647..0c2be9421ab78f 100644
--- a/drivers/s390/cio/vfio_ccw_cp.c
+++ b/drivers/s390/cio/vfio_ccw_cp.c
@@ -103,13 +103,13 @@ static int pfn_array_pin(struct pfn_array *pa, struct vfio_device *vdev)
{
int ret = 0;

- ret = vfio_pin_pages(vdev->dev, pa->pa_iova_pfn, pa->pa_nr,
+ ret = vfio_pin_pages(vdev, pa->pa_iova_pfn, pa->pa_nr,
IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);

if (ret < 0) {
goto err_out;
} else if (ret > 0 && ret != pa->pa_nr) {
- vfio_unpin_pages(vdev->dev, pa->pa_iova_pfn, ret);
+ vfio_unpin_pages(vdev, pa->pa_iova_pfn, ret);
ret = -EINVAL;
goto err_out;
}
@@ -127,7 +127,7 @@ static void pfn_array_unpin_free(struct pfn_array *pa, struct vfio_device *vdev)
{
/* Only unpin if any pages were pinned to begin with */
if (pa->pa_nr)
- vfio_unpin_pages(vdev->dev, pa->pa_iova_pfn, pa->pa_nr);
+ vfio_unpin_pages(vdev, pa->pa_iova_pfn, pa->pa_nr);
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
}
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index bfa7ee6ef532d9..e8914024f5b1af 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -124,8 +124,7 @@ static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
q->saved_isc = VFIO_AP_ISC_INVALID;
}
if (q->saved_pfn && !WARN_ON(!q->matrix_mdev)) {
- vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
- &q->saved_pfn, 1);
+ vfio_unpin_pages(&q->matrix_mdev->vdev, &q->saved_pfn, 1);
q->saved_pfn = 0;
}
}
@@ -258,7 +257,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
return status;
}

- ret = vfio_pin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1,
+ ret = vfio_pin_pages(&q->matrix_mdev->vdev, &g_pfn, 1,
IOMMU_READ | IOMMU_WRITE, &h_pfn);
switch (ret) {
case 1:
@@ -301,7 +300,7 @@ static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
break;
case AP_RESPONSE_OTHERWISE_CHANGED:
/* We could not modify IRQ setings: clear new configuration */
- vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1);
+ vfio_unpin_pages(&q->matrix_mdev->vdev, &g_pfn, 1);
kvm_s390_gisc_unregister(kvm, isc);
break;
default:
@@ -1250,7 +1249,7 @@ static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
struct vfio_iommu_type1_dma_unmap *unmap = data;
unsigned long g_pfn = unmap->iova >> PAGE_SHIFT;

- vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1);
+ vfio_unpin_pages(&matrix_mdev->vdev, &g_pfn, 1);
return NOTIFY_OK;
}

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 13494c1e497405..dc5d40b07e2381 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1927,32 +1927,26 @@ EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
* @phys_pfn[out]: array of host PFNs
* Return error or number of pages pinned.
*/
-int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
+int vfio_pin_pages(struct vfio_device *vdev, unsigned long *user_pfn, int npage,
int prot, unsigned long *phys_pfn)
{
struct vfio_container *container;
- struct vfio_group *group;
+ struct vfio_group *group = vdev->group;
struct vfio_iommu_driver *driver;
int ret;

- if (!dev || !user_pfn || !phys_pfn || !npage)
+ if (!user_pfn || !phys_pfn || !npage)
return -EINVAL;

if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
return -E2BIG;

- group = vfio_group_get_from_dev(dev);
- if (!group)
- return -ENODEV;
-
- if (group->dev_counter > 1) {
- ret = -EINVAL;
- goto err_pin_pages;
- }
+ if (group->dev_counter > 1)
+ return -EINVAL;

ret = vfio_group_add_container_user(group);
if (ret)
- goto err_pin_pages;
+ return ret;

container = group->container;
driver = container->iommu_driver;
@@ -1965,8 +1959,6 @@ int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,

vfio_group_try_dissolve_container(group);

-err_pin_pages:
- vfio_group_put(group);
return ret;
}
EXPORT_SYMBOL(vfio_pin_pages);
@@ -1980,28 +1972,24 @@ EXPORT_SYMBOL(vfio_pin_pages);
* be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
* Return error or number of pages unpinned.
*/
-int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
+int vfio_unpin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
+ int npage)
{
struct vfio_container *container;
- struct vfio_group *group;
struct vfio_iommu_driver *driver;
int ret;

- if (!dev || !user_pfn || !npage)
+ if (!user_pfn || !npage)
return -EINVAL;

if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
return -E2BIG;

- group = vfio_group_get_from_dev(dev);
- if (!group)
- return -ENODEV;
-
- ret = vfio_group_add_container_user(group);
+ ret = vfio_group_add_container_user(vdev->group);
if (ret)
- goto err_unpin_pages;
+ return ret;

- container = group->container;
+ container = vdev->group->container;
driver = container->iommu_driver;
if (likely(driver && driver->ops->unpin_pages))
ret = driver->ops->unpin_pages(container->iommu_data, user_pfn,
@@ -2009,10 +1997,8 @@ int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
else
ret = -ENOTTY;

- vfio_group_try_dissolve_container(group);
+ vfio_group_try_dissolve_container(vdev->group);

-err_unpin_pages:
- vfio_group_put(group);
return ret;
}
EXPORT_SYMBOL(vfio_unpin_pages);
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 748ec0e0293aea..8f2a09801a660b 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -150,9 +150,9 @@ extern long vfio_external_check_extension(struct vfio_group *group,

#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))

-extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
+extern int vfio_pin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
int npage, int prot, unsigned long *phys_pfn);
-extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
+extern int vfio_unpin_pages(struct vfio_device *vdev, unsigned long *user_pfn,
int npage);

extern int vfio_group_pin_pages(struct vfio_group *group,
--
2.36.0