[PATCH v1 2/2] vfio:iommu: Get DMA information from real IOMMU

Pierre Morel
2019-01-09T12:41:54Z

We report the real IOMMU geometry through the VFIO_IOMMU_GET_INFO
ioctl call when the vfio_iommu_type1_info support capabilities.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
---
drivers/vfio/vfio_iommu_type1.c | 43 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index d9fd318..0a7746c 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1673,6 +1673,23 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
return ret;
}

+static int vfio_iommu_type1_caps(struct vfio_iommu *iommu,
+ struct vfio_info_cap *caps)
+{
+ struct vfio_domain *d;
+ struct vfio_iommu_cap_dma info = { .header.id = VFIO_IOMMU_INFO_CAP_DMA,
+ .header.version = 1 };
+ int ret;
+
+ d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
+ if (!d || !d->domain)
+ return -ENODEV;
+ info.dma_start = d->domain->geometry.aperture_start;
+ info.dma_end = d->domain->geometry.aperture_end;
+ ret = vfio_info_add_capability(caps, &info.header, sizeof(info));
+ return ret;
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -1694,6 +1711,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
}
} else if (cmd == VFIO_IOMMU_GET_INFO) {
struct vfio_iommu_type1_info info;
+ struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
+ int ret;

minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);

@@ -1703,7 +1722,29 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
if (info.argsz < minsz)
return -EINVAL;

- info.flags = VFIO_IOMMU_INFO_PGSIZES;
+ if (info.flags & VFIO_IOMMU_INFO_CAPABILITIES) {
+ ret = vfio_iommu_type1_caps(iommu, &caps);
+ if (ret)
+ return ret;
+ }
+ if (caps.size) {
+ if (info.argsz < sizeof(info) + caps.size) {
+ info.argsz = sizeof(info) + caps.size;
+ info.cap_offset = 0;
+ } else {
+ vfio_info_cap_shift(&caps, sizeof(info));
+ if (copy_to_user((void __user *)arg +
+ sizeof(info), caps.buf,
+ caps.size)) {
+ kfree(caps.buf);
+ return -EFAULT;
+ }
+ info.cap_offset = sizeof(info);
+ }
+ kfree(caps.buf);
+ }
+
+ info.flags |= VFIO_IOMMU_INFO_PGSIZES;

info.iova_pgsizes = vfio_pgsize_bitmap(iommu);

--
2.7.4