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.au...@redhat.com> --- 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