| Message ID | 20230112164403.105085-7-david@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-mem: Handle preallocation with migration | expand |
* David Hildenbrand (david@redhat.com) wrote: > "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> > Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > hw/virtio/virtio-mem.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c > index 1ed1f5a4af..02f7b5469a 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) || > -- > 2.39.0 >
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c index 1ed1f5a4af..02f7b5469a 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) ||