1.https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg03651.html
2.https://lists.linuxfoundation.org/pipermail/iommu/2016-
November/019002.html
3.https://patchwork.kernel.org/patch/10084655/
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/vfio/vfio_iommu_type1.c | 172
+++++++++++++++++++++++++++++++++++++++-
include/uapi/linux/vfio.h | 13 +++
2 files changed, 184 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index e30e29a..72ca78a 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -28,6 +28,7 @@
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/iommu.h>
+#include <linux/list_sort.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
@@ -92,6 +93,12 @@ struct vfio_group {
struct list_head next;
};
+struct vfio_iommu_iova {
+ struct list_head list;
+ phys_addr_t start;
+ phys_addr_t end;
+};
+
/*
* Guest RAM pinning working set or DMA target
*/
@@ -1537,6 +1544,144 @@ static int vfio_domains_have_iommu_cache(struct
vfio_iommu *iommu)
return ret;
}
+static int vfio_add_iova_cap(struct vfio_info_cap *caps, u64 start, u64 end)
+{
+ struct vfio_iommu_type1_info_cap_iova_range *cap;
+ struct vfio_info_cap_header *header;
+
+ header = vfio_info_cap_add(caps, sizeof(*cap),
+ VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);
+ if (IS_ERR(header))
+ return PTR_ERR(header);
+
+ cap = container_of(header,
+ struct vfio_iommu_type1_info_cap_iova_range,
+ header);
+
+ cap->start = start;
+ cap->end = end;
+
+ return 0;
+}
+
+static int vfio_insert_iova(phys_addr_t start, phys_addr_t end,
+ struct list_head *head)
+{
+ struct vfio_iommu_iova *region;
+
+ region = kzalloc(sizeof(*region), GFP_KERNEL);
+ if (!region)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(®ion->list);
+ region->start = start;
+ region->end = end;
+
+ list_add_tail(®ion->list, head);
+ return 0;
+}
+
+/*
+ * Check and update iova region list in case a reserved region
+ * overlaps the iommu iova range.
+ */
+static int vfio_update_iommu_iova_range(phys_addr_t start, phys_addr_t end,
+ struct list_head *iova)
+{
+ struct vfio_iommu_iova *node;
+ phys_addr_t a, b;
+ int ret = 0;
+
+ if (list_empty(iova))
+ return -ENODEV;
+
+ node = list_last_entry(iova, struct vfio_iommu_iova, list);
+ a = node->start;
+ b = node->end;
+
+ /* No overlap */
+ if ((start > b) || (end < a))
+ return 0;
+
+ if (start > a)
+ ret = vfio_insert_iova(a, start - 1, &node->list);
+ if (ret)
+ goto done;
+ if (end < b)
+ ret = vfio_insert_iova(end + 1, b, &node->list);
+
+done:
+ list_del(&node->list);
+ kfree(node);
+
+ return ret;
+}
+
+static int vfio_resv_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct iommu_resv_region *ra, *rb;
+
+ ra = container_of(a, struct iommu_resv_region, list);
+ rb = container_of(b, struct iommu_resv_region, list);
+
+ if (ra->start < rb->start)
+ return -1;
+ if (ra->start > rb->start)
+ return 1;
+ return 0;
+}
+
+static int vfio_build_iommu_iova_caps(struct vfio_iommu *iommu,
+ struct vfio_info_cap *caps)
+{
+ struct iommu_resv_region *resv, *resv_next;
+ struct vfio_iommu_iova *iova, *iova_next;
+ struct list_head group_resv_regions, vfio_iova_regions;
+ struct vfio_domain *domain;
+ struct vfio_group *g;
+ phys_addr_t start, end;
+ int ret = 0;
+
+ domain = list_first_entry(&iommu->domain_list,
+ struct vfio_domain, next);
+ /* Get the default iova range supported */
+ start = domain->domain->geometry.aperture_start;
+ end = domain->domain->geometry.aperture_end;
+ INIT_LIST_HEAD(&vfio_iova_regions);
+ vfio_insert_iova(start, end, &vfio_iova_regions);
+
+ /* Get reserved regions if any */
+ INIT_LIST_HEAD(&group_resv_regions);
+ list_for_each_entry(g, &domain->group_list, next)
+ iommu_get_group_resv_regions(g->iommu_group,
+ &group_resv_regions);
+ list_sort(NULL, &group_resv_regions, vfio_resv_cmp);
+
+ /* Update iova range excluding reserved regions */
+ list_for_each_entry(resv, &group_resv_regions, list) {
+ ret = vfio_update_iommu_iova_range(resv->start,
+ resv->start + resv->length - 1,
+ &vfio_iova_regions);
+ if (ret)
+ goto done;
+ }
+
+ list_for_each_entry(iova, &vfio_iova_regions, list) {
+ ret = vfio_add_iova_cap(caps, iova->start, iova->end);
+ if (ret)
+ goto done;
+ }
+
+done:
+ list_for_each_entry_safe(resv, resv_next, &group_resv_regions, list)
+ kfree(resv);
+
+ list_for_each_entry_safe(iova, iova_next, &vfio_iova_regions, list)
+ kfree(iova);
+
+ return ret;
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -1558,8 +1703,10 @@ 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);
+ minsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
@@ -1571,6 +1718,29 @@ static long vfio_iommu_type1_ioctl(void
*iommu_data,
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
+ ret = vfio_build_iommu_iova_caps(iommu, &caps);
+ if (ret)
+ return ret;
+
+ if (caps.size) {
+ info.flags |= VFIO_IOMMU_INFO_CAPS;
+ 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);
+ }
+
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index e3301db..c4e338b 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -517,7 +517,20 @@ struct vfio_iommu_type1_info {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */
+#define VFIO_IOMMU_INFO_CAPS (1 << 1) /* Info supports caps */
__u64 iova_pgsizes; /* Bitmap of supported page sizes */
+ __u32 cap_offset; /* Offset within info struct of first cap */
+ __u32 __resv;
+};
+
+/*
+ * The IOVA_RANGE capability allows to report the IOVA range(s),
+ */
+#define VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE 1
+struct vfio_iommu_type1_info_cap_iova_range {
+ struct vfio_info_cap_header header;
+ __u64 start;
+ __u64 end;
};
#define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12)
--
1.9.1
