public/qemu
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

docs/zoned-storage:add zoned emulation use case

Browse source 
Add the documentation about the example of using virtio-blk driver
to pass the zoned block devices through to the guest.

Signed-off-by: Sam Li <faithilikerun@gmail.com>
Message-id: 20230508051916.178322-5-faithilikerun@gmail.com
[Fix pre-formatted code syntax
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Sam Li 2023-05-08 13:19:16 +08:00 committed by Stefan Hajnoczi
parent 4e92acf74d
commit 01562fee5f
1 changed files with 19 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

19
docs/devel/zoned-storage.rst
View file

@ -41,3 +41,22 @@ APIs for zoned storage emulation or testing.
For example, to test zone_report on a null_blk device using qemu-io is:: For example, to test zone_report on a null_blk device using qemu-io is::
$ path/to/qemu-io --image-opts -n driver=host_device,filename=/dev/nullb0 -c "zrp offset nr_zones" $ path/to/qemu-io --image-opts -n driver=host_device,filename=/dev/nullb0 -c "zrp offset nr_zones"
To expose the host's zoned block device through virtio-blk, the command line
can be (includes the -device parameter)::
-blockdev node-name=drive0,driver=host_device,filename=/dev/nullb0,cache.direct=on \
-device virtio-blk-pci,drive=drive0
Or only use the -drive parameter::
-driver driver=host_device,file=/dev/nullb0,if=virtio,cache.direct=on
Additionally, QEMU has several ways of supporting zoned storage, including:
(1) Using virtio-scsi: --device scsi-block allows for the passing through of
SCSI ZBC devices, enabling the attachment of ZBC or ZAC HDDs to QEMU.
(2) PCI device pass-through: While NVMe ZNS emulation is available for testing
purposes, it cannot yet pass through a zoned device from the host. To pass on
the NVMe ZNS device to the guest, use VFIO PCI pass the entire NVMe PCI adapter
through to the guest. Likewise, an HDD HBA can be passed on to QEMU all HDDs
attached to the HBA.