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| author | David Hildenbrand <david@redhat.com> | 2023-01-17 12:22:47 +0100 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2023-02-06 19:22:56 +0100 |
| commit | ce1761f0f9f0dde30a56cdcff68c034874fb91a0 (patch) | |
| tree | 83d89c9e084cdef0b7ec09ccbc7b88992a0a3caa | |
| parent | 80fe315c384153af957ee94d43d08b90ad1d5ef7 (diff) | |
| download | qemu-ce1761f0f9f0dde30a56cdcff68c034874fb91a0.zip qemu-ce1761f0f9f0dde30a56cdcff68c034874fb91a0.tar.gz qemu-ce1761f0f9f0dde30a56cdcff68c034874fb91a0.tar.bz2 | |
virtio-mem: Fail if a memory backend with "prealloc=on" is specified
"prealloc=on" for the memory backend does not work as expected, as
virtio-mem will simply discard all preallocated memory immediately again.
In the best case, it's an expensive NOP. In the worst case, it's an
unexpected allocation error.
Instead, "prealloc=on" should be specified for the virtio-mem device only,
such that virtio-mem will try preallocating memory before plugging
memory dynamically to the guest. Fail if such a memory backend is
provided.
Tested-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>S
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
| -rw-r--r-- | hw/virtio/virtio-mem.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index 1ed1f5a..02f7b54 100644 --- a/hw/virtio/virtio-mem.c +++ b/hw/virtio/virtio-mem.c @@ -772,6 +772,12 @@ static void virtio_mem_device_realize(DeviceState *dev, Error **errp) error_setg(errp, "'%s' property specifies an unsupported memdev", VIRTIO_MEM_MEMDEV_PROP); return; + } else if (vmem->memdev->prealloc) { + error_setg(errp, "'%s' property specifies a memdev with preallocation" + " enabled: %s. Instead, specify 'prealloc=on' for the" + " virtio-mem device. ", VIRTIO_MEM_MEMDEV_PROP, + object_get_canonical_path_component(OBJECT(vmem->memdev))); + return; } if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) || |