Re: [PATCH v5 09/14] hw/block/nvme: Support Zoned Namespace Command Set

[Niklas Cassel]

On Mon, Sep 28, 2020 at 11:35:23AM +0900, Dmitry Fomichev wrote:
> The emulation code has been changed to advertise NVM Command Set when
> "zoned" device property is not set (default) and Zoned Namespace
> Command Set otherwise.
> 
> Handlers for three new NVMe commands introduced in Zoned Namespace
> Command Set specification are added, namely for Zone Management
> Receive, Zone Management Send and Zone Append.
> 
> Device initialization code has been extended to create a proper
> configuration for zoned operation using device properties.
> 
> Read/Write command handler is modified to only allow writes at the
> write pointer if the namespace is zoned. For Zone Append command,
> writes implicitly happen at the write pointer and the starting write
> pointer value is returned as the result of the command. Write Zeroes
> handler is modified to add zoned checks that are identical to those
> done as a part of Write flow.
> 
> The code to support for Zone Descriptor Extensions is not included in
> this commit and ZDES 0 is always reported. A later commit in this
> series will add ZDE support.
> 
> This commit doesn't yet include checks for active and open zone
> limits. It is assumed that there are no limits on either active or
> open zones.
> 
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
> Signed-off-by: Ajay Joshi <ajay.joshi@wdc.com>
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> Signed-off-by: Matias Bjorling <matias.bjorling@wdc.com>
> Signed-off-by: Aravind Ramesh <aravind.ramesh@wdc.com>
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
> Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
> ---
>  block/nvme.c         |   2 +-
>  hw/block/nvme-ns.c   | 185 ++++++++-
>  hw/block/nvme-ns.h   |   6 +-
>  hw/block/nvme.c      | 872 +++++++++++++++++++++++++++++++++++++++++--
>  include/block/nvme.h |   6 +-
>  5 files changed, 1033 insertions(+), 38 deletions(-)
> 
> diff --git a/block/nvme.c b/block/nvme.c
> index 05485fdd11..7a513c9a17 100644
> --- a/block/nvme.c
> +++ b/block/nvme.c

(snip)

> @@ -1326,11 +2060,20 @@ static uint16_t nvme_cmd_effects(NvmeCtrl *n, 
> uint32_t buf_len,
>      acs[NVME_ADM_CMD_GET_LOG_PAGE] = NVME_CMD_EFFECTS_CSUPP;
>      acs[NVME_ADM_CMD_ASYNC_EV_REQ] = NVME_CMD_EFFECTS_CSUPP;
>  
> -    iocs[NVME_CMD_FLUSH] = NVME_CMD_EFFECTS_CSUPP | NVME_CMD_EFFECTS_LBCC;
> -    iocs[NVME_CMD_WRITE_ZEROES] = NVME_CMD_EFFECTS_CSUPP |
> -                                  NVME_CMD_EFFECTS_LBCC;
> -    iocs[NVME_CMD_WRITE] = NVME_CMD_EFFECTS_CSUPP | NVME_CMD_EFFECTS_LBCC;
> -    iocs[NVME_CMD_READ] = NVME_CMD_EFFECTS_CSUPP;
> +    if (NVME_CC_CSS(n->bar.cc) != CSS_ADMIN_ONLY) {
> +        iocs[NVME_CMD_FLUSH] = NVME_CMD_EFFECTS_CSUPP | 
> NVME_CMD_EFFECTS_LBCC;
> +        iocs[NVME_CMD_WRITE_ZEROES] = NVME_CMD_EFFECTS_CSUPP |
> +                                      NVME_CMD_EFFECTS_LBCC;
> +        iocs[NVME_CMD_WRITE] = NVME_CMD_EFFECTS_CSUPP | 
> NVME_CMD_EFFECTS_LBCC;
> +        iocs[NVME_CMD_READ] = NVME_CMD_EFFECTS_CSUPP;
> +    }
> +
> +    if (csi == NVME_CSI_ZONED && NVME_CC_CSS(n->bar.cc) == CSS_CSI) {

Actually, intead of naming the helper function, ctrl_has_zns_namespaces(),
a better name might be ctrl_has_zns_support()

Since this is what is used to set the bit in nvme_identify_cmd_set(),

Then, I think that this should be:

if (ctrl_has_zns_support() && csi == NVME_CSI_ZONED && NVME_CC_CSS(n->bar.cc) 
== CSS_CSI) {


> +        iocs[NVME_CMD_ZONE_APPEND] = NVME_CMD_EFFECTS_CSUPP |
> +                                     NVME_CMD_EFFECTS_LBCC;
> +        iocs[NVME_CMD_ZONE_MGMT_SEND] = NVME_CMD_EFFECTS_CSUPP;
> +        iocs[NVME_CMD_ZONE_MGMT_RECV] = NVME_CMD_EFFECTS_CSUPP;
> +    }
>  
>      trans_len = MIN(sizeof(cmd_eff_log) - off, buf_len);
>