From: Marc-André Lureau <marcandre.lureau@redhat.com>

This was never turned off, effectively some dead code.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 include/system/memory.h       | 12 +-----------
 hw/vfio/listener.c            |  2 +-
 hw/virtio/virtio-mem.c        | 22 ++--------------------
 system/ram-block-attributes.c | 23 +----------------------
 4 files changed, 5 insertions(+), 54 deletions(-)

diff --git a/include/system/memory.h b/include/system/memory.h
index 0562af31361..be36fd93dc0 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -580,26 +580,16 @@ struct RamDiscardListener {
      */
     NotifyRamDiscard notify_discard;
 
-    /*
-     * @double_discard_supported:
-     *
-     * The listener suppors getting @notify_discard notifications that span
-     * already discarded parts.
-     */
-    bool double_discard_supported;
-
     MemoryRegionSection *section;
     QLIST_ENTRY(RamDiscardListener) next;
 };
 
 static inline void ram_discard_listener_init(RamDiscardListener *rdl,
                                              NotifyRamPopulate populate_fn,
-                                             NotifyRamDiscard discard_fn,
-                                             bool double_discard_supported)
+                                             NotifyRamDiscard discard_fn)
 {
     rdl->notify_populate = populate_fn;
     rdl->notify_discard = discard_fn;
-    rdl->double_discard_supported = double_discard_supported;
 }
 
 /**
diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
index 1087fdc142e..960da9e0a93 100644
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -283,7 +283,7 @@ static bool vfio_ram_discard_register_listener(VFIOContainer *bcontainer,
 
     ram_discard_listener_init(&vrdl->listener,
                               vfio_ram_discard_notify_populate,
-                              vfio_ram_discard_notify_discard, true);
+                              vfio_ram_discard_notify_discard);
     ram_discard_manager_register_listener(rdm, &vrdl->listener, section);
     QLIST_INSERT_HEAD(&bcontainer->vrdl_list, vrdl, next);
 
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
index c1e2defb68e..251d1d50aaa 100644
--- a/hw/virtio/virtio-mem.c
+++ b/hw/virtio/virtio-mem.c
@@ -331,14 +331,6 @@ static int virtio_mem_notify_populate_cb(MemoryRegionSection *s, void *arg)
     return rdl->notify_populate(rdl, s);
 }
 
-static int virtio_mem_notify_discard_cb(MemoryRegionSection *s, void *arg)
-{
-    RamDiscardListener *rdl = arg;
-
-    rdl->notify_discard(rdl, s);
-    return 0;
-}
-
 static void virtio_mem_notify_unplug(VirtIOMEM *vmem, uint64_t offset,
                                      uint64_t size)
 {
@@ -398,12 +390,7 @@ static void virtio_mem_notify_unplug_all(VirtIOMEM *vmem)
     }
 
     QLIST_FOREACH(rdl, &vmem->rdl_list, next) {
-        if (rdl->double_discard_supported) {
-            rdl->notify_discard(rdl, rdl->section);
-        } else {
-            virtio_mem_for_each_plugged_section(vmem, rdl->section, rdl,
-                                                virtio_mem_notify_discard_cb);
-        }
+        rdl->notify_discard(rdl, rdl->section);
     }
 }
 
@@ -1824,12 +1811,7 @@ static void virtio_mem_rdm_unregister_listener(RamDiscardManager *rdm,
 
     g_assert(rdl->section->mr == &vmem->memdev->mr);
     if (vmem->size) {
-        if (rdl->double_discard_supported) {
-            rdl->notify_discard(rdl, rdl->section);
-        } else {
-            virtio_mem_for_each_plugged_section(vmem, rdl->section, rdl,
-                                                virtio_mem_notify_discard_cb);
-        }
+        rdl->notify_discard(rdl, rdl->section);
     }
 
     memory_region_section_free_copy(rdl->section);
diff --git a/system/ram-block-attributes.c b/system/ram-block-attributes.c
index 9f72a6b3545..630b0fda126 100644
--- a/system/ram-block-attributes.c
+++ b/system/ram-block-attributes.c
@@ -61,16 +61,6 @@ ram_block_attributes_notify_populate_cb(MemoryRegionSection *section,
     return rdl->notify_populate(rdl, section);
 }
 
-static int
-ram_block_attributes_notify_discard_cb(MemoryRegionSection *section,
-                                       void *arg)
-{
-    RamDiscardListener *rdl = arg;
-
-    rdl->notify_discard(rdl, section);
-    return 0;
-}
-
 static int
 ram_block_attributes_for_each_populated_section(const RamBlockAttributes *attr,
                                                 MemoryRegionSection *section,
@@ -191,22 +181,11 @@ ram_block_attributes_rdm_unregister_listener(RamDiscardManager *rdm,
                                              RamDiscardListener *rdl)
 {
     RamBlockAttributes *attr = RAM_BLOCK_ATTRIBUTES(rdm);
-    int ret;
 
     g_assert(rdl->section);
     g_assert(rdl->section->mr == attr->ram_block->mr);
 
-    if (rdl->double_discard_supported) {
-        rdl->notify_discard(rdl, rdl->section);
-    } else {
-        ret = ram_block_attributes_for_each_populated_section(attr,
-                rdl->section, rdl, ram_block_attributes_notify_discard_cb);
-        if (ret) {
-            error_report("%s: Failed to unregister RAM discard listener: %s",
-                         __func__, strerror(-ret));
-            exit(1);
-        }
-    }
+    rdl->notify_discard(rdl, rdl->section);
 
     memory_region_section_free_copy(rdl->section);
     rdl->section = NULL;
-- 
2.52.0

On 2/4/26 11:06, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> This was never turned off, effectively some dead code.
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>   include/system/memory.h       | 12 +-----------
>   hw/vfio/listener.c            |  2 +-
>   hw/virtio/virtio-mem.c        | 22 ++--------------------
>   system/ram-block-attributes.c | 23 +----------------------
>   4 files changed, 5 insertions(+), 54 deletions(-)


Reviewed-by: Cédric Le Goater <clg@redhat.com

Thanks,

C.