* Mon Oct 07 2024 Miroslav Rezanina <mrezanin@redhat.com> - 9.1.0-3

- kvm-hostmem-Apply-merge-property-after-the-memory-region.patch [RHEL-58936]
- Resolves: RHEL-58936
  ([RHEL-10.0] QEMU core dump on applying merge property to memory backend)

kvm-hostmem-Apply-merge-property-after-the-memory-region.patch

@@ -0,0 +1,61 @@
+From d0163127a47250170e01e39f48250a2725f531c0 Mon Sep 17 00:00:00 2001
+From: Gavin Shan <gshan@redhat.com>
+Date: Tue, 1 Oct 2024 16:58:57 +1000
+Subject: [PATCH] hostmem: Apply merge property after the memory region is
+ initialized
+
+RH-Author: Gavin Shan <gshan@redhat.com>
+RH-MergeRequest: 272: hostmem: Apply merge property after the memory region is initialized
+RH-Jira: RHEL-58936
+RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
+RH-Acked-by: Eric Auger <eric.auger@redhat.com>
+RH-Acked-by: David Hildenbrand <david@redhat.com>
+RH-Commit: [1/1] aa47bedf64698b277bb8835f4689d4f1d5eca53c (gwshan/qemu-centos)
+
+JIRA: https://issues.redhat.com/browse/RHEL-58936
+
+The semantic change has been introduced by commit 5becdc0ab0 ("hostmem:
+simplify the code for merge and dump properties") even it clarifies that
+no senmatic change has been introduced. After the commit, the merge
+property can be applied even the corresponding memory region isn't
+initialized yet. This leads to crash dump by the following command
+lines.
+
+  # /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64  \
+    -accel kvm  -machine virt -cpu host                      \
+    -object memory-backend-ram,id=mem-memN0,size=4096M,merge=off
+    :
+    qemu-system-aarch64: ../system/memory.c:2419: memory_region_get_ram_ptr: \
+    Assertion `mr->ram_block' failed.
+
+Fix it by applying the merge property only when the memory region is
+initialized.
+
+Message-ID: <20240915233117.478169-1-gshan@redhat.com>
+Fixes: 5becdc0ab083 ("hostmem: simplify the code for merge and dump properties")
+Reported-by: Zhenyu Zhang <zhenyzha@redhat.com>
+Tested-by: Zhenyu Zhang <zhenyzha@redhat.com>
+Signed-off-by: Gavin Shan <gshan@redhat.com>
+Signed-off-by: David Hildenbrand <david@redhat.com>
+(cherry picked from commit 78c8f780d3f0d6d17aa93d6f99ff72960080fdd7)
+Signed-off-by: Gavin Shan <gshan@redhat.com>
+---
+ backends/hostmem.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/backends/hostmem.c b/backends/hostmem.c
+index 4e5576a4ad..181446626a 100644
+--- a/backends/hostmem.c
++++ b/backends/hostmem.c
+@@ -178,7 +178,7 @@ static void host_memory_backend_set_merge(Object *obj, bool value, Error **errp)
+         return;
+     }
+ 
+-    if (!host_memory_backend_mr_inited(backend) &&
++    if (host_memory_backend_mr_inited(backend) &&
+         value != backend->merge) {
+         void *ptr = memory_region_get_ram_ptr(&backend->mr);
+         uint64_t sz = memory_region_size(&backend->mr);
+-- 
+2.39.3
+

qemu-kvm.spec

@@ -143,7 +143,7 @@ Obsoletes: %{name}-block-ssh <= %{epoch}:%{version}                    \
 Summary: QEMU is a machine emulator and virtualizer
 Name: qemu-kvm
 Version: 9.1.0
-Release: 2%{?rcrel}%{?dist}%{?cc_suffix}
+Release: 3%{?rcrel}%{?dist}%{?cc_suffix}
 # Epoch because we pushed a qemu-1.0 package. AIUI this can't ever be dropped
 # Epoch 15 used for RHEL 8
 # Epoch 17 used for RHEL 9 (due to release versioning offset in RHEL 8.5)
@@ -235,6 +235,8 @@ Patch32: kvm-remove-stale-compat-definitions.patch
 Patch33: kvm-RH-Author-Shaoqin-Huang-shahuang-redhat.com.patch
 # For RHEL-57028 - fsfreeze hooks break on the systems first restorecon [rhel-10]
 Patch34: kvm-qemu-guest-agent-Update-the-logfile-path-of-qga-fsfr.patch
+# For RHEL-58936 - [RHEL-10.0] QEMU core dump on applying merge property to memory backend
+Patch35: kvm-hostmem-Apply-merge-property-after-the-memory-region.patch
 
 %if %{have_clang}
 BuildRequires: clang
@@ -1302,6 +1304,11 @@ useradd -r -u 107 -g qemu -G kvm -d / -s /sbin/nologin \
 %endif
 
 %changelog
+* Mon Oct 07 2024 Miroslav Rezanina <mrezanin@redhat.com> - 9.1.0-3
+- kvm-hostmem-Apply-merge-property-after-the-memory-region.patch [RHEL-58936]
+- Resolves: RHEL-58936
+  ([RHEL-10.0] QEMU core dump on applying merge property to memory backend)
+
 * Mon Sep 30 2024 Miroslav Rezanina <mrezanin@redhat.com> - 9.1.0-2
 - kvm-x86-create-new-pc-q35-machine-type-for-rhel-9.6.patch [RHEL-29002 RHEL-29003 RHEL-35587 RHEL-38411 RHEL-45141]
 - kvm-arm-create-new-virt-machine-type-for-rhel-9.6.patch [RHEL-29002 RHEL-29003 RHEL-35587 RHEL-38411 RHEL-45141]