1. 10 Nov, 2021 1 commit
    • David Hildenbrand's avatar
      virtio-mem: support VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE · 61082ad6
      David Hildenbrand authored
      The initial virtio-mem spec states that while unplugged memory should not
      be read, the device still has to allow for reading unplugged memory inside
      the usable region. The primary motivation for this default handling was
      to simplify bringup of virtio-mem, because there were corner cases where
      Linux might have accidentially read unplugged memory inside added Linux
      memory blocks.
      
      In the meantime, we:
      1. Removed /dev/kmem in commit bbcd53c9 ("drivers/char: remove
         /dev/kmem for good")
      2. Disallowed access to virtio-mem device memory via /dev/mem in
         commit 2128f4e2 ("virtio-mem: disallow mapping virtio-mem memory via
         /dev/mem")
      3. Sanitized access to virtio-mem device memory via /proc/kcore in
         commit 0daa322b ("fs/proc/kcore: don't read offline sections,
         logically offline pages and hwpoisoned pages")
      4. Sanitized access to virtio-mem device memory via /proc/vmcore in
         commit ce281462 ("virtio-mem: kdump mode to sanitize /proc/vmcore
         access")
      
      "Accidential" access to unplugged memory is no longer possible; we can
      support the new VIRTIO_MEM_F_UNPLUGGED_INACCESSIBLE feature that will be
      required by some hypervisors implementing virtio-mem in the near future.
      Acked-by: default avatarMichael S. Tsirkin <mst@redhat.com>
      Cc: "Michael S. Tsirkin" <mst@redhat.com>
      Cc: Jason Wang <jasowang@redhat.com>
      Cc: Marek Kedzierski <mkedzier@redhat.com>
      Cc: Hui Zhu <teawater@gmail.com>
      Cc: Sebastien Boeuf <sebastien.boeuf@intel.com>
      Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
      Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
      Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
      61082ad6
  2. 09 Nov, 2021 39 commits