On 10/24/25 10:43, Zhenzhong Duan wrote:
When doing ditry tracking or calculating dirty tracking range, readonly
regions can be bypassed, because corresponding DMA mappings are readonly
and never become dirty.
This can optimize dirty tracking a bit for passthrough device.
Signed-off-by: Zhenzhong Duan <[email protected]>
---
hw/vfio/listener.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
index 0862b2b834..cbd86c79af 100644
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -828,7 +828,8 @@ static void vfio_dirty_tracking_update(MemoryListener
*listener,
container_of(listener, VFIODirtyRangesListener, listener);
hwaddr iova, end;
- if (!vfio_listener_valid_section(section, false, "tracking_update") ||
+ /* Bypass readonly section as it never become dirty */
+ if (!vfio_listener_valid_section(section, true, "tracking_update") ||
!vfio_get_section_iova_range(dirty->bcontainer, section,
&iova, &end, NULL)) {
return;
@@ -1087,6 +1088,12 @@ static void vfio_iommu_map_dirty_notify(IOMMUNotifier
*n, IOMMUTLBEntry *iotlb)
if (!mr) {
goto out_unlock;
}
+
+ if (!(iotlb->perm & IOMMU_WO) || mr->readonly) {
In case you resend, please add a trace event.
Anyhow,
Reviewed-by: Cédric Le Goater <[email protected]>
Thanks,
C.
+ rcu_read_unlock();
+ return;
+ }
+
translated_addr = memory_region_get_ram_addr(mr) + xlat;
ret = vfio_container_query_dirty_bitmap(bcontainer, iova, iotlb->addr_mask + 1,
@@ -1222,7 +1229,7 @@ static void vfio_listener_log_sync(MemoryListener
*listener,
int ret;
Error *local_err = NULL;
- if (vfio_listener_skipped_section(section, false)) {
+ if (vfio_listener_skipped_section(section, true)) {
return;
}
