[PATCH v6 03/11] igvm: cleanup memory regions

[Ani Sinha <anisinha@redhat.com>]

From: Gerd Hoffmann <kraxel@redhat.com>

This change cleans up existing memory regions that were created by the current
IGVM. The cleanup would be necessary when a new IGVM is loaded. This cleanup
function is called in a subsequent patch.

Reviewed-by: Alexander Graf <graf@amazon.com>
Tested-by: Ani Sinha <anisinha@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 backends/igvm-cfg.c   |  2 ++
 backends/igvm.c       | 19 +++++++++++++++++++
 include/system/igvm.h |  1 +
 3 files changed, 22 insertions(+)

diff --git a/backends/igvm-cfg.c b/backends/igvm-cfg.c
index 38438a7b1e..935ba54f54 100644
--- a/backends/igvm-cfg.c
+++ b/backends/igvm-cfg.c
@@ -52,6 +52,8 @@ static void igvm_reset_hold(Object *obj, ResetType type)
 
     trace_igvm_reset_hold(type);
 
+    /* cleanup existing memory regions first */
+    qigvm_cleanup_memory(igvm);
     qigvm_process_file(igvm, ms, false, &error_fatal);
 }
 
diff --git a/backends/igvm.c b/backends/igvm.c
index 9e7c90d386..9b101c8182 100644
--- a/backends/igvm.c
+++ b/backends/igvm.c
@@ -14,6 +14,7 @@
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/target-info-qapi.h"
+#include "migration/vmstate.h"
 #include "system/igvm.h"
 #include "system/igvm-cfg.h"
 #include "system/igvm-internal.h"
@@ -1109,3 +1110,21 @@ cleanup_parameters:
 cleanup:
     return retval;
 }
+
+/*
+ * cleanup any memory regions created by qigvm_prepare_memory()
+ */
+void qigvm_cleanup_memory(IgvmCfg *cfg)
+{
+    IgvmMemoryRegion *imr, *tmp;
+
+    QTAILQ_FOREACH_SAFE(imr, &cfg->memory_regions, next, tmp)
+    {
+        memory_region_del_subregion(get_system_memory(), imr->mr);
+        vmstate_unregister_ram(imr->mr, NULL);
+        QTAILQ_REMOVE(&cfg->memory_regions, imr, next);
+        /* this triggers MemoryRegion cleanup */
+        object_unparent(OBJECT(imr->mr));
+        g_free(imr);
+    }
+}
diff --git a/include/system/igvm.h b/include/system/igvm.h
index 64d3542311..e219f1a4ed 100644
--- a/include/system/igvm.h
+++ b/include/system/igvm.h
@@ -20,6 +20,7 @@ typedef struct QIgvm QIgvm;
 
 int qigvm_process_file(IgvmCfg *igvm, MachineState *machine_state,
                        bool onlyVpContext, Error **errp);
+void qigvm_cleanup_memory(IgvmCfg *igvm);
 
 /* x86 native */
 int qigvm_x86_get_mem_map_entry(int index,
-- 
2.42.0