even if an entry overlaps with notifier's range, should not map/unmap out of bound part in the entry.
This would cause problem in below case: 1. initially there are two notifiers with ranges 0-0xfedfffff, 0xfef00000-0xffffffffffffffff, IOVAs from 0x3c000000 - 0x3c1fffff is in shadow page table. 2. in vfio, memory_region_register_iommu_notifier() is followed by memory_region_iommu_replay(), which will first call address space unmap, and walk and add back all entries in vtd shadow page table. e.g. (1) for notifier 0-0xfedfffff, IOVAs from 0 - 0xffffffff get unmapped, and IOVAs from 0x3c000000 - 0x3c1fffff get mapped (2) for notifier 0xfef00000-0xffffffffffffffff IOVAs from 0 - 0x7fffffffff get unmapped, but IOVAs from 0x3c000000 - 0x3c1fffff cannot get mapped back. Signed-off-by: Yan Zhao <yan.y.z...@intel.com> --- memory.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/memory.c b/memory.c index 07c8315..a6b9da6 100644 --- a/memory.c +++ b/memory.c @@ -1948,6 +1948,14 @@ void memory_region_notify_one(IOMMUNotifier *notifier, return; } + if (entry->iova < notifier->start) { + entry->iova = notifier->start; + } + + if (entry->iova + entry->addr_mask > notifier->end) { + entry->addr_mask = notifier->end - entry->iova; + } + if (entry->perm & IOMMU_RW) { printf("map %lx %lx\n", entry->iova, entry->iova + entry->addr_mask); request_flags = IOMMU_NOTIFIER_MAP; -- 2.7.4