On 11/30/21 10:28, David Hildenbrand wrote: > TODO: replace by a proper header sync. > > Signed-off-by: David Hildenbrand <da...@redhat.com> > --- > include/standard-headers/linux/virtio_mem.h | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/include/standard-headers/linux/virtio_mem.h > b/include/standard-headers/linux/virtio_mem.h > index 05e5ade75d..18c74c527c 100644 > --- a/include/standard-headers/linux/virtio_mem.h > +++ b/include/standard-headers/linux/virtio_mem.h > @@ -68,9 +68,10 @@ > * explicitly triggered (VIRTIO_MEM_REQ_UNPLUG). > * > * There are no guarantees what will happen if unplugged memory is > - * read/written. Such memory should, in general, not be touched. E.g., > - * even writing might succeed, but the values will simply be discarded at > - * random points in time. > + * read/written. In general, unplugged memory should not be touched, because > + * the resulting action is undefined. There is one exception: without > + * VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE, unplugged memory inside the usable > + * region can be read, to simplify creation of memory dumps. > * > * It can happen that the device cannot process a request, because it is > * busy. The device driver has to retry later. > @@ -87,6 +88,8 @@ > > /* node_id is an ACPI PXM and is valid */ > #define VIRTIO_MEM_F_ACPI_PXM 0 > +/* unplugged memory must not be accessed */ > +#define VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE 1 > > > /* --- virtio-mem: guest -> host requests --- */ >
This is verbatim copy of kernel commit of 61082ad6a6e1f. Reviewed-by: Michal Privoznik <mpriv...@redhat.com> Michal
