From ad721705d09c62f0d108a6b4f59867ebfd592c90 Mon Sep 17 00:00:00 2001 From: Kirti Wankhede Date: Fri, 29 May 2020 02:00:53 +0530 Subject: [PATCH] vfio iommu: Add migration capability to report supported features Added migration capability in IOMMU info chain. User application should check IOMMU info chain for migration capability to use dirty page tracking feature provided by kernel module. User application must check page sizes supported and maximum dirty bitmap size returned by this capability structure for ioctls used to get dirty bitmap. Signed-off-by: Kirti Wankhede Reviewed-by: Cornelia Huck Reviewed-by: Yan Zhao Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 23 ++++++++++++++++++++++- include/uapi/linux/vfio.h | 23 +++++++++++++++++++++++ 2 files changed, 45 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index e31fcc23e81a..f5c6ca46f165 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -2423,6 +2423,22 @@ static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu, return ret; } +static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu, + struct vfio_info_cap *caps) +{ + struct vfio_iommu_type1_info_cap_migration cap_mig; + + cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION; + cap_mig.header.version = 1; + + cap_mig.flags = 0; + /* support minimum pgsize */ + cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap); + cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX; + + return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig)); +} + static long vfio_iommu_type1_ioctl(void *iommu_data, unsigned int cmd, unsigned long arg) { @@ -2469,8 +2485,13 @@ static long vfio_iommu_type1_ioctl(void *iommu_data, info.iova_pgsizes = iommu->pgsize_bitmap; - ret = vfio_iommu_iova_build_caps(iommu, &caps); + ret = vfio_iommu_migration_build_caps(iommu, &caps); + + if (!ret) + ret = vfio_iommu_iova_build_caps(iommu, &caps); + mutex_unlock(&iommu->lock); + if (ret) return ret; diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index ff4b6706f7df..fde4692a6989 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -1013,6 +1013,29 @@ struct vfio_iommu_type1_info_cap_iova_range { struct vfio_iova_range iova_ranges[]; }; +/* + * The migration capability allows to report supported features for migration. + * + * The structures below define version 1 of this capability. + * + * The existence of this capability indicates that IOMMU kernel driver supports + * dirty page logging. + * + * pgsize_bitmap: Kernel driver returns bitmap of supported page sizes for dirty + * page logging. + * max_dirty_bitmap_size: Kernel driver returns maximum supported dirty bitmap + * size in bytes that can be used by user applications when getting the dirty + * bitmap. + */ +#define VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION 1 + +struct vfio_iommu_type1_info_cap_migration { + struct vfio_info_cap_header header; + __u32 flags; + __u64 pgsize_bitmap; + __u64 max_dirty_bitmap_size; /* in bytes */ +}; + #define VFIO_IOMMU_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 12) /**