From: Gavin Shan Date: Sun, 15 Sep 2024 23:31:17 +0000 (+1000) Subject: hostmem: Apply merge property after the memory region is initialized X-Git-Tag: v9.2.0-rc0~74^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=78c8f780d3f0d6d17aa93d6f99ff72960080fdd7;p=thirdparty%2Fqemu.git hostmem: Apply merge property after the memory region is initialized 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 Tested-by: Zhenyu Zhang Signed-off-by: Gavin Shan Signed-off-by: David Hildenbrand --- diff --git a/backends/hostmem.c b/backends/hostmem.c index 4e5576a4ada..181446626ae 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);