Describe use of new protection info block-level passthrough nvme feature. Signed-off-by: Dmitry Tihov <d.ti...@yadro.com> --- docs/system/devices/nvme.rst | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/docs/system/devices/nvme.rst b/docs/system/devices/nvme.rst index 30f841ef62..7375379810 100644 --- a/docs/system/devices/nvme.rst +++ b/docs/system/devices/nvme.rst @@ -240,6 +240,21 @@ The virtual namespace device supports DIF- and DIX-based protection information metadata. Otherwise, the protection information is transferred as the last eight bytes. +Virtual namespace device can also be backed by integrity capable host block +device. This way protection information is passed through to/from the host block +device from/to the guest and checked by the host block device itself instead of QEMU. + +``pip=BOOL`` (default: ``off``) + Set to ``on`` to allow host block device protection information passthrough. + +To use this feature nvme-ns backend drive must have Linux io_uring AIO backend +and host page cache must be avoided. E.g. the following parameters should be used: + +.. code-block:: console + + -drive file=/dev/nvme0n1,cache.direct=on,aio=io_uring,format=raw,if=none,id=dif_drive_0 + -device nvme-ns,logical_block_size=4096,physical_block_size=4096,drive=dif_drive_0,pip=on + Virtualization Enhancements and SR-IOV (Experimental Support) ------------------------------------------------------------- -- 2.38.1
