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[PULL,6/6] hostmem: Apply merge property after the memory region is initialized

Message ID 20240924100329.248738-7-david@redhat.com (mailing list archive)
State New, archived
Headers show
Series [PULL,1/6] virtio: kconfig: memory devices are PCI only | expand

Commit Message

David Hildenbrand Sept. 24, 2024, 10:03 a.m. UTC 
From: Gavin Shan <gshan@redhat.com>

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>
---
 backends/hostmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

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);