From: Yao Xingtao <yaoxt.fnst@fujitsu.com>

When injecting a new poisoned region through qmp_cxl_inject_poison(),
the newly injected region should not overlap with existing poisoned
regions.

The current validation method does not consider the following
overlapping region:
┌───┬───────┬───┐
│a  │  b(a) │a  │
└───┴───────┴───┘
(a is a newly added region, b is an existing region, and b is a
 subregion of a)

Fixes: 9547754f40ee ("hw/cxl: QMP based poison injection support")
Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20241014121902.2146424-4-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/mem/cxl_type3.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index 44d491d8f6..16c60b9b0d 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -1381,9 +1381,7 @@ void qmp_cxl_inject_poison(const char *path, uint64_t start, uint64_t length,
     ct3d = CXL_TYPE3(obj);
 
     QLIST_FOREACH(p, &ct3d->poison_list, node) {
-        if (((start >= p->start) && (start < p->start + p->length)) ||
-            ((start + length > p->start) &&
-             (start + length <= p->start + p->length))) {
+        if ((start < p->start + p->length) && (start + length > p->start)) {
             error_setg(errp,
                        "Overlap with existing poisoned region not supported");
             return;
-- 
MST