Re: [PATCH 3/9] vfio/mdev: Pass in a struct vfio_device * to vfio_pin/unpin_pages()

On Tue, 2022-04-12 at 12:53 -0300, Jason Gunthorpe wrote:

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.

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 | 8 ++-- drivers/vfio/vfio.c | 40 ++++++----------- -- include/linux/vfio.h | 4 +- 5 files changed, 24 insertions(+), 38 deletions(-)

For the -ccw bits:

Acked-by: Eric Farman farman@linux.ibm.com

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 9f26079cacae35..6aeca741dc9be1 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -279,10 +279,10 @@ 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,

• 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);

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 af5048a1ba8894..e362cb962a7234 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 69768061cd7bd9..a10b3369d76c41 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -124,7 +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),
  

• vfio_unpin_pages(&q->matrix_mdev->vdev,
  	 &q->saved_pfn, 1);
  

  q->saved_pfn = 0; }

@@ -258,7 +258,7 @@ 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 +301,7 @@ 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 +1250,7 @@ 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 8a5c46aa2bef61..24b92a45cfc8f1 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -2142,32 +2142,26 @@ 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;

@@ -2180,8 +2174,6 @@ 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); @@ -2195,28 +2187,24 @@ 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, @@ -2224,10 +2212,8 @@ 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,