memory: assert on out of scope notification
It is wrong for an entry to have parts out of scope of notifier's range.
assert this condition.
Out of scope mapping/unmapping would cause problem, as 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.
Cc: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
Message-Id: <1561432878-13754-1-git-send-email-yan.y.zhao@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/memory.c b/memory.c
index 8141486..c90a2cf 100644
--- a/memory.c
+++ b/memory.c
@@ -1942,16 +1942,18 @@
IOMMUTLBEntry *entry)
{
IOMMUNotifierFlag request_flags;
+ hwaddr entry_end = entry->iova + entry->addr_mask;
/*
* Skip the notification if the notification does not overlap
* with registered range.
*/
- if (notifier->start > entry->iova + entry->addr_mask ||
- notifier->end < entry->iova) {
+ if (notifier->start > entry_end || notifier->end < entry->iova) {
return;
}
+ assert(entry->iova >= notifier->start && entry_end <= notifier->end);
+
if (entry->perm & IOMMU_RW) {
request_flags = IOMMU_NOTIFIER_MAP;
} else {
