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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>
hifive-unleashed-5.1
Alex Williamson 2014-02-26 11:38:37 -07:00
parent 1ef3e2bc04
commit aa42931827
2 changed files with 26 additions and 0 deletions
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21
drivers/vfio/vfio_iommu_type1.c
View File

@ -867,6 +867,23 @@ static void vfio_iommu_type1_release(void *iommu_data)
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 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
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;
}

5
include/uapi/linux/vfio.h
View File

@ -24,6 +24,11 @@
#define VFIO_TYPE1_IOMMU 1
#define VFIO_SPAPR_TCE_IOMMU 2
#define VFIO_TYPE1v2_IOMMU 3
/*
* IOMMU enforces DMA cache coherence (ex. PCIe NoSnoop stripping). This
* capability is subject to change as groups are added or removed.
*/
#define VFIO_DMA_CC_IOMMU 4
/*
* The IOCTL interface is designed for extensibility by embedding the