From 661984f4c417a5ccd3b739ad89cfd4b9907f4146 Mon Sep 17 00:00:00 2001
Message-Id: <661984f4c417a5ccd3b739ad89cfd4b9907f4146.1444668695.git.jen@redhat.com>
In-Reply-To: <860bcb286a4f0cfcc02e2d5c16c2c94f85fddf12.1444668695.git.jen@redhat.com>
References: <860bcb286a4f0cfcc02e2d5c16c2c94f85fddf12.1444668695.git.jen@redhat.com>
From: Markus Armbruster <armbru@redhat.com>
Date: Fri, 9 Oct 2015 14:37:30 -0500
Subject: [CHANGE 03/11] memory: allow destroying a non-empty MemoryRegion
To: rhvirt-patches@redhat.com,
jen@redhat.com
RH-Author: Markus Armbruster <armbru@redhat.com>
Message-id: <1444401458-7995-2-git-send-email-armbru@redhat.com>
Patchwork-id: 68107
O-Subject: [RHEV-7.2 qemu-kvm-rhev PATCH v2 1/9] memory: allow destroying a non-empty MemoryRegion
Bugzilla: 1264347
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Eduardo Habkost <ehabkost@redhat.com>
From: Paolo Bonzini <pbonzini@redhat.com>
This is legal; the MemoryRegion will simply unreference all the
existing subregions and possibly bring them down with it as well.
However, it requires a bit of care to avoid an infinite loop.
Finalizing a memory region cannot trigger an address space update,
but memory_region_del_subregion errs on the side of caution and
might trigger a spurious update: avoid that by resetting mr->enabled
first.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1443689999-12182-2-git-send-email-armbru@redhat.com>
(cherry picked from commit 2e2b8eb70fdb7dfbec39f3a19b20f9a73f2f813e)
---
memory.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
Signed-off-by: Jeff E. Nelson <jen@redhat.com>
---
memory.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/memory.c b/memory.c
index 7de38a5..85f353f 100644
--- a/memory.c
+++ b/memory.c
@@ -1312,7 +1312,22 @@ static void memory_region_finalize(Object *obj)
{
MemoryRegion *mr = MEMORY_REGION(obj);
- assert(QTAILQ_EMPTY(&mr->subregions));
+ assert(!mr->container);
+
+ /* We know the region is not visible in any address space (it
+ * does not have a container and cannot be a root either because
+ * it has no references, so we can blindly clear mr->enabled.
+ * memory_region_set_enabled instead could trigger a transaction
+ * and cause an infinite loop.
+ */
+ mr->enabled = false;
+ memory_region_transaction_begin();
+ while (!QTAILQ_EMPTY(&mr->subregions)) {
+ MemoryRegion *subregion = QTAILQ_FIRST(&mr->subregions);
+ memory_region_del_subregion(mr, subregion);
+ }
+ memory_region_transaction_commit();
+
mr->destructor(mr);
memory_region_clear_coalescing(mr);
g_free((char *)mr->name);
--
2.4.3