vfio/type1: Add extension to test DMA cache coherence of IOMMU
Now that the type1 IOMMU backend can support IOMMU_CACHE, we need to
be able to test whether coherency is currently enforced. Add an
extension for this.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 8c7bb9b..1f90344 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -867,6 +867,23 @@
kfree(iommu);
}
+static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
+{
+ struct vfio_domain *domain;
+ int ret = 1;
+
+ mutex_lock(&iommu->lock);
+ list_for_each_entry(domain, &iommu->domain_list, next) {
+ if (!(domain->prot & IOMMU_CACHE)) {
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&iommu->lock);
+
+ return ret;
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -878,6 +895,10 @@
case VFIO_TYPE1_IOMMU:
case VFIO_TYPE1v2_IOMMU:
return 1;
+ case VFIO_DMA_CC_IOMMU:
+ if (!iommu)
+ return 0;
+ return vfio_domains_have_iommu_cache(iommu);
default:
return 0;
}