[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v4] memory: assert on out of scope notification
From: |
Yan Zhao |
Subject: |
[Qemu-devel] [PATCH v4] memory: assert on out of scope notification |
Date: |
Tue, 25 Jun 2019 11:21:18 +0800 |
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 <address@hidden>
Signed-off-by: Yan Zhao <address@hidden>
---
v4:
1. modified commit title
2. using "assert" instead of printing warning message
(Eric Auger)
v3:
refined code style and message format
v2:
1. added a local variable entry_end (Eric Auger)
2. using PRIx64 as format for address range in warning message
(Eric Auger)
---
memory.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/memory.c b/memory.c
index 0a089a7..35e8e77 100644
--- a/memory.c
+++ b/memory.c
@@ -1937,16 +1937,18 @@ void memory_region_notify_one(IOMMUNotifier *notifier,
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 {
--
2.7.4
- [Qemu-devel] [PATCH v4] memory: assert on out of scope notification,
Yan Zhao <=