From: David Hildenbrand <da...@redhat.com> Let's synchronize the new feature flag, available in Linux since v5.16-rc1.
Reviewed-by: Michal Privoznik <mpriv...@redhat.com> Signed-off-by: David Hildenbrand <da...@redhat.com> Message-Id: <20211217134039.29670-2-da...@redhat.com> Reviewed-by: Michael S. Tsirkin <m...@redhat.com> Signed-off-by: Michael S. Tsirkin <m...@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 --- */ -- MST
