On Thu, Jul 14, 2022 at 06:18:22PM +1000, Alexey Kardashevskiy wrote:
+/*
+ * A simple iommu_ops to allow less cruft in generic VFIO code.
+ */
+static bool spapr_tce_iommu_capable(enum iommu_cap cap)
+{
+ switch (cap) {
+ case IOMMU_CAP_CACHE_COHERENCY:
I would add a remark here that it is because vfio is going to use
SPAPR mode but still checks that the iommu driver support coherency -
with out that detail it looks very strange to have caps without
implementing unmanaged domains
+static struct iommu_domain *spapr_tce_iommu_domain_alloc(unsigned int type)
+{
+ struct iommu_domain *dom;
+
+ if (type != IOMMU_DOMAIN_BLOCKED)
+ return NULL;
+
+ dom = kzalloc(sizeof(*dom), GFP_KERNEL);
+ if (!dom)
+ return NULL;
+
+ dom->geometry.aperture_start = 0;
+ dom->geometry.aperture_end = ~0ULL;
+ dom->geometry.force_aperture = true;
A blocked domain doesn't really have an aperture, all DMA is rejected,
so I think these can just be deleted and left at zero.
Generally I'm suggesting drivers just use a static singleton instance
for the blocked domain instead of the allocation like this, but that
is a very minor nit.
+static struct iommu_device *spapr_tce_iommu_probe_device(struct device *dev)
+{
+ struct pci_dev *pdev;
+ struct pci_controller *hose;
+
+ /* Weirdly iommu_device_register() assigns the same ops to all buses */
+ if (!dev_is_pci(dev))
+ return ERR_PTR(-EPERM);
Less "weirdly", more by design. The iommu driver should check if the
given struct device is supported or not, it isn't really a bus
specific operation.
+static struct iommu_group *spapr_tce_iommu_device_group(struct device *dev)
+{
+ struct pci_controller *hose;
+ struct pci_dev *pdev;
+
+ /* Weirdly iommu_device_register() assigns the same ops to all buses */
+ if (!dev_is_pci(dev))
+ return ERR_PTR(-EPERM);
This doesn't need repeating, if probe_device() fails then this will
never be called.
+static int spapr_tce_iommu_attach_dev(struct iommu_domain *dom,
+ struct device *dev)
+{
+ struct iommu_group *grp = iommu_group_get(dev);
+ struct iommu_table_group *table_group;
+ int ret = -EINVAL;
+
+ if (!grp)
+ return -ENODEV;
+
+ table_group = iommu_group_get_iommudata(grp);
+
+ if (dom->type == IOMMU_DOMAIN_BLOCKED)
+ ret = table_group->ops->take_ownership(table_group);
Ideally there shouldn't be dom->type checks like this.
The blocking domain should have its own iommu_domain_ops that only
process the blocking operation. Ie call this like
spapr_tce_iommu_blocking_attach_dev()
Instead of having a "default_domain_ops" leave it NULL and create a
spapr_tce_blocking_domain_ops with these two functions and assign it
to domain->ops when creating. Then it is really clear these functions
are only called for the DOMAIN_BLOCKED type and you don't need to
check it.
+static void spapr_tce_iommu_detach_dev(struct iommu_domain *dom,
+ struct device *dev)
+{
+ struct iommu_group *grp = iommu_group_get(dev);
+ struct iommu_table_group *table_group;
+
+ table_group = iommu_group_get_iommudata(grp);
+ WARN_ON(dom->type != IOMMU_DOMAIN_BLOCKED);
+ table_group->ops->release_ownership(table_group);
+}
Ditto
+struct iommu_group *pSeries_pci_device_group(struct pci_controller *hose,
+ struct pci_dev *pdev)
+{
+ struct device_node *pdn, *dn = pdev->dev.of_node;
+ struct iommu_group *grp;
+ struct pci_dn *pci;
+
+ pdn = pci_dma_find(dn, NULL);
+ if (!pdn || !PCI_DN(pdn))
+ return ERR_PTR(-ENODEV);
+
+ pci = PCI_DN(pdn);
+ if (!pci->table_group)
+ return ERR_PTR(-ENODEV);
+
+ grp = pci->table_group->group;
+ if (!grp)
+ return ERR_PTR(-ENODEV);
+
+ return iommu_group_ref_get(grp);
Not for this series, but this is kind of backwards, the driver
specific data (ie the table_group) should be in
iommu_group_get_iommudata()...
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 8a65ea61744c..3b53b466e49b 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -1152,8 +1152,6 @@ static void tce_iommu_release_ownership(struct tce_container *container,
for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
if (container->tables[i])
table_group->ops->unset_window(table_group, i);
-
- table_group->ops->release_ownership(table_group);
}
static long tce_iommu_take_ownership(struct tce_container *container,
@@ -1161,10 +1159,6 @@ static long tce_iommu_take_ownership(struct tce_container *container,
{
long i, ret = 0;
- ret = table_group->ops->take_ownership(table_group);
- if (ret)
- return ret;
-
/* Set all windows to the new group */
for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
struct iommu_table *tbl = container->tables[i];
@@ -1183,8 +1177,6 @@ static long tce_iommu_take_ownership(struct tce_container *container,
for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
table_group->ops->unset_window(table_group, i);
- table_group->ops->release_ownership(table_group);
-
This is great, makes alot of sense.
Anyhow, it all looks fine to me as is even:
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
