diff options
Diffstat (limited to 'docs/about')
| -rw-r--r-- | docs/about/deprecated.rst | 22 | ||||
| -rw-r--r-- | docs/about/removed-features.rst | 14 |
2 files changed, 14 insertions, 22 deletions
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 1e21fbbf77..48b230b0a0 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -314,28 +314,6 @@ the addition of volatile memory support, it is now necessary to distinguish between persistent and volatile memory backends. As such, memdev is deprecated in favor of persistent-memdev. -``-fsdev proxy`` and ``-virtfs proxy`` (since 8.1) -^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -The 9p ``proxy`` filesystem backend driver has been deprecated and will be -removed (along with its proxy helper daemon) in a future version of QEMU. Please -use ``-fsdev local`` or ``-virtfs local`` for using the 9p ``local`` filesystem -backend, or alternatively consider deploying virtiofsd instead. - -The 9p ``proxy`` backend was originally developed as an alternative to the 9p -``local`` backend. The idea was to enhance security by dispatching actual low -level filesystem operations from 9p server (QEMU process) over to a separate -process (the virtfs-proxy-helper binary). However this alternative never gained -momentum. The proxy backend is much slower than the local backend, hasn't seen -any development in years, and showed to be less secure, especially due to the -fact that its helper daemon must be run as root, whereas with the local backend -QEMU is typically run as unprivileged user and allows to tighten behaviour by -mapping permissions et al by using its 'mapped' security model option. - -Nowadays it would make sense to reimplement the ``proxy`` backend by using -QEMU's ``vhost`` feature, which would eliminate the high latency costs under -which the 9p ``proxy`` backend currently suffers. However as of to date nobody -has indicated plans for such kind of reimplementation unfortunately. RISC-V CPU properties which start with capital 'Z' (since 8.2) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst index 6e96cd067f..c76b91a88d 100644 --- a/docs/about/removed-features.rst +++ b/docs/about/removed-features.rst @@ -517,6 +517,20 @@ The virtio-blk SCSI passthrough feature is a legacy VIRTIO feature. VIRTIO 1.0 and later do not support it because the virtio-scsi device was introduced for full SCSI support. Use virtio-scsi instead when SCSI passthrough is required. +``-fsdev proxy`` and ``-virtfs proxy`` (since 9.2) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The 9p ``proxy`` filesystem backend driver was originally developed to +enhance security by dispatching low level filesystem operations from 9p +server (QEMU process) over to a separate process (the virtfs-proxy-helper +binary). However the proxy backend was much slower than the local backend, +didn't see any development in years, and showed to be less secure, +especially due to the fact that its helper daemon must be run as root. + +Use ``local``, possibly mapping permissions et al by using its 'mapped' +security model option, or switch to ``virtiofs``. The virtiofs daemon +``virtiofsd`` uses vhost to eliminate the high latency costs of the 9p +``proxy`` backend. User-mode emulator command line arguments ----------------------------------------- |