Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
include/exec/memory.h | 3 +++
softmmu/memory.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 6fa0b071f0..5154b123d8 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -791,6 +791,9 @@ struct MemoryRegion {
unsigned ioeventfd_nb;
MemoryRegionIoeventfd *ioeventfds;
RamDiscardManager *rdm; /* Only for RAM */
+
+ /* For devices designed to perform re-entrant IO into their own IO MRs */
+ bool disable_reentrancy_guard;
};
struct IOMMUMemoryRegion {
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 57bf18a257..3018fa2edb 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -544,7 +544,7 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
}
/* Do not allow more than one simultanous access to a device's IO Regions */
- if (mr->owner &&
+ if (mr->owner && !mr->disable_reentrancy_guard &&
!mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
if (dev) {