This patch allows the user-space to retrieve the reserved IOVA range(s),
if any. The implementation is based on capability chains, now also added
to VFIO_IOMMU_GET_INFO.
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
---
RFC v1 -> v2:
- add resv_mutex lock/unlock
---
drivers/vfio/vfio_iommu_type1.c | 70 ++++++++++++++++++++++++++++++++++++++++-
include/uapi/linux/vfio.h | 16 +++++++++-
2 files changed, 84 insertions(+), 2 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 2ba1942..205f6ad 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -965,6 +965,49 @@ static int vfio_domains_have_iommu_cache(struct vfio_iommu *iommu)
return ret;
}
+static int add_resv_iova_range(struct vfio_info_cap *caps, u64 start, u64 end)
+{
+ struct vfio_iommu_type1_info_cap_resv_iova_range *cap;
+ struct vfio_info_cap_header *header;
+
+ header = vfio_info_cap_add(caps, sizeof(*cap),
+ VFIO_IOMMU_TYPE1_INFO_CAP_RESV_IOVA_RANGE, 1);
+
+ if (IS_ERR(header))
+ return PTR_ERR(header);
+
+ cap = container_of(header,
+ struct vfio_iommu_type1_info_cap_resv_iova_range,
+ header);
+
+ cap->start = start;
+ cap->end = end;
+ return 0;
+}
+
+static int build_resv_iova_range_caps(struct vfio_iommu *iommu,
+ struct vfio_info_cap *caps)
+{
+ struct iommu_reserved_region *resv;
+ struct vfio_domain *domain;
+ struct iommu_domain *d;
+ int ret = 0;
+
+ domain = list_first_entry(&iommu->domain_list,
+ struct vfio_domain, next);
+ d = domain->domain;
+
+ mutex_lock(&d->resv_mutex);
+ iommu_reserved_region_for_each(resv, d) {
+ ret = add_resv_iova_range(caps, resv->start,
+ resv->start + resv->length - 1);
+ if (ret)
+ break;
+ }
+ mutex_unlock(&d->resv_mutex);
+ return ret;
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -986,8 +1029,10 @@ 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;
@@ -999,6 +1044,29 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
+ ret = build_resv_iova_range_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 255a211..ae96f2c 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -488,7 +488,21 @@ struct vfio_iommu_type1_info {
__u32 argsz;
__u32 flags;
#define VFIO_IOMMU_INFO_PGSIZES (1 << 0) /* supported page sizes info */
- __u64 iova_pgsizes; /* Bitmap of supported page sizes */
+#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 RESV_IOVA_RANGE capability allows to report the reserved IOVA range(s),
+ * if any.
+ */
+#define VFIO_IOMMU_TYPE1_INFO_CAP_RESV_IOVA_RANGE 1
+struct vfio_iommu_type1_info_cap_resv_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
--
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