[PATCH v6 02/11] igvm: track memory regions

[Ani Sinha <anisinha@redhat.com>]

From: Gerd Hoffmann <kraxel@redhat.com>

Memory regions added by the current IGVM needs to be tracked so that they can be
freed when a new IGVM is loaded.

Reviewed-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 backends/igvm-cfg.c            |  1 +
 backends/igvm.c                | 20 ++++++++++++--------
 include/system/igvm-internal.h |  6 ++++++
 3 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/backends/igvm-cfg.c b/backends/igvm-cfg.c
index e1f09855f6..38438a7b1e 100644
--- a/backends/igvm-cfg.c
+++ b/backends/igvm-cfg.c
@@ -65,6 +65,7 @@ static void igvm_complete(UserCreatable *uc, Error **errp)
     IgvmCfg *igvm = IGVM_CFG(uc);
 
     igvm->file = qigvm_file_init(igvm->filename, errp);
+    QTAILQ_INIT(&igvm->memory_regions);
 }
 
 OBJECT_DEFINE_TYPE_WITH_INTERFACES(IgvmCfg, igvm_cfg, IGVM_CFG, OBJECT,
diff --git a/backends/igvm.c b/backends/igvm.c
index 534032fed8..9e7c90d386 100644
--- a/backends/igvm.c
+++ b/backends/igvm.c
@@ -220,7 +220,7 @@ static void *qigvm_prepare_memory(QIgvm *ctx, uint64_t addr, uint64_t size,
                                   int region_identifier, Error **errp)
 {
     ERRP_GUARD();
-    MemoryRegion *igvm_pages = NULL;
+    IgvmMemoryRegion *imr = NULL;
     Int128 gpa_region_size;
     MemoryRegionSection mrs =
         memory_region_find(get_system_memory(), addr, size);
@@ -254,23 +254,27 @@ static void *qigvm_prepare_memory(QIgvm *ctx, uint64_t addr, uint64_t size,
          */
         g_autofree char *region_name =
             g_strdup_printf("igvm.%X", region_identifier);
-        igvm_pages = g_new0(MemoryRegion, 1);
+        imr = g_new0(IgvmMemoryRegion, 1);
+        imr->mr = g_new0(MemoryRegion, 1);
         if (ctx->machine_state->cgs &&
             ctx->machine_state->cgs->require_guest_memfd) {
-            if (!memory_region_init_ram_guest_memfd(igvm_pages, NULL,
+            if (!memory_region_init_ram_guest_memfd(imr->mr, NULL,
                                                     region_name, size, errp)) {
-                g_free(igvm_pages);
+                g_free(imr->mr);
+                g_free(imr);
                 return NULL;
             }
         } else {
-            if (!memory_region_init_ram(igvm_pages, NULL, region_name, size,
+            if (!memory_region_init_ram(imr->mr, NULL, region_name, size,
                                         errp)) {
-                g_free(igvm_pages);
+                g_free(imr->mr);
+                g_free(imr);
                 return NULL;
             }
         }
-        memory_region_add_subregion(get_system_memory(), addr, igvm_pages);
-        return memory_region_get_ram_ptr(igvm_pages);
+        memory_region_add_subregion(get_system_memory(), addr, imr->mr);
+        QTAILQ_INSERT_TAIL(&ctx->cfg->memory_regions, imr, next);
+        return memory_region_get_ram_ptr(imr->mr);
     }
 }
 
diff --git a/include/system/igvm-internal.h b/include/system/igvm-internal.h
index b5720fae0c..9e9fa1d9af 100644
--- a/include/system/igvm-internal.h
+++ b/include/system/igvm-internal.h
@@ -18,6 +18,11 @@
 #include "system/confidential-guest-support.h"
 #include <igvm/igvm.h>
 
+typedef struct IgvmMemoryRegion {
+    QTAILQ_ENTRY(IgvmMemoryRegion) next;
+    MemoryRegion *mr;
+} IgvmMemoryRegion;
+
 struct IgvmCfg {
     Object parent_obj;
 
@@ -29,6 +34,7 @@ struct IgvmCfg {
     char *filename;
     IgvmHandle file;
     ResettableState reset_state;
+    QTAILQ_HEAD(, IgvmMemoryRegion) memory_regions;
 };
 
 typedef struct QIgvmParameterData {
-- 
2.42.0