Re: [PATCH v8 0/4] Add zoned storage emulation to virtio-blk driver

Sam Li
2023-03-23T13:38:51Z

Matias Bjørling <m@bjorling.me> 于2023年3月23日周四 21:26写道：
>
> On 23/03/2023 06.28, Sam Li wrote:
> > This patch adds zoned storage emulation to the virtio-blk driver.
> >
> > The patch implements the virtio-blk ZBD support standardization that is
> > recently accepted by virtio-spec. The link to related commit is at
> >
> > https://github.com/oasis-tcs/virtio-spec/commit/b4e8efa0fa6c8d844328090ad15db65af8d7d981
> >
> > The Linux zoned device code that implemented by Dmitry Fomichev has been
> > released at the latest Linux version v6.3-rc1.
> >
> > Aside: adding zoned=on alike options to virtio-blk device will be
> > considered in following-up plan.
> >
> > v7:
> > - address Stefan's review comments
> > * rm aio_context_acquire/release in handle_req
> > * rename function return type
> > * rename BLOCK_ACCT_APPEND to BLOCK_ACCT_ZONE_APPEND for clarity
> >
> > v6:
> > - update headers to v6.3-rc1
> >
> > v5:
> > - address Stefan's review comments
> > * restore the way writing zone append result to buffer
> > * fix error checking case and other errands
> >
> > v4:
> > - change the way writing zone append request result to buffer
> > - change zone state, zone type value of virtio_blk_zone_descriptor
> > - add trace events for new zone APIs
> >
> > v3:
> > - use qemuio_from_buffer to write status bit [Stefan]
> > - avoid using req->elem directly [Stefan]
> > - fix error checkings and memory leak [Stefan]
> >
> > v2:
> > - change units of emulated zone op coresponding to block layer APIs
> > - modify error checking cases [Stefan, Damien]
> >
> > v1:
> > - add zoned storage emulation
> >
> > Sam Li (4):
> > include: update virtio_blk headers to v6.3-rc1
> > virtio-blk: add zoned storage emulation for zoned devices
> > block: add accounting for zone append operation
> > virtio-blk: add some trace events for zoned emulation
> >
> > block/qapi-sysemu.c | 11 +
> > block/qapi.c | 18 +
> > hw/block/trace-events | 7 +
> > hw/block/virtio-blk-common.c | 2 +
> > hw/block/virtio-blk.c | 405 +++++++++++++++++++
> > include/block/accounting.h | 1 +
> > include/standard-headers/drm/drm_fourcc.h | 12 +
> > include/standard-headers/linux/ethtool.h | 48 ++-
> > include/standard-headers/linux/fuse.h | 45 ++-
> > include/standard-headers/linux/pci_regs.h | 1 +
> > include/standard-headers/linux/vhost_types.h | 2 +
> > include/standard-headers/linux/virtio_blk.h | 105 +++++
> > linux-headers/asm-arm64/kvm.h | 1 +
> > linux-headers/asm-x86/kvm.h | 34 +-
> > linux-headers/linux/kvm.h | 9 +
> > linux-headers/linux/vfio.h | 15 +-
> > linux-headers/linux/vhost.h | 8 +
> > qapi/block-core.json | 62 ++-
> > qapi/block.json | 4 +
> > 19 files changed, 769 insertions(+), 21 deletions(-)
> >
>
>
> Hi Sam,
>
> I applied your patches and can report that they work with both SMR HDDs
> and ZNS SSDs. Very nice work!
>
> Regarding the documentation (docs/system/qemu-block-drivers.rst.inc). Is
> it possible to expose the host's zoned block device through something
> else than virtio-blk? If not, I wouldn't mind seeing the documentation
> updated to show a case when using the virtio-blk driver.
>
> For example (this also includes the device part):
>
> -device virtio-blk-pci,drive=drive0,id=virtblk0 \
> -blockdev
> host_device,node-name=drive0,filename=/dev/nullb0,cache.direct=on``
>
> It might also be nice to describe the shorthand for those that likes to
> pass in the parameters using only the -drive parameter.
>
> -drive driver=host_device,file=/dev/nullb0,if=virtio,cache.direct=on

Hi Matias,

I'm glad it works. Thanks for your feedback!

For the question, this patch is exposing the zoned interface through
virtio-blk only. It's a good suggestion to put a use case inside
documentation. I will add it in the subsequent patch.

Thanks,
Sam