On Wed, Oct 14, 2020 at 06:42:06AM +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.
>
> Define values and structures that are needed to support Zoned
> Namespace Command Set (NVMe TP 4053) in PCI NVMe controller emulator.
> Define trace events where needed in newly introduced code.
>
> In order to improve scalability, all open, closed and full zones
> are organized in separate linked lists. Consequently, almost all
> zone operations don't require scanning of the entire zone array
> (which potentially can be quite large) - it is only necessary to
> enumerate one or more zone lists.
>
> 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.
>
> Subsequent commits in this series add ZDE support and checks for
> active and open zone limits.
>
> Signed-off-by: Niklas Cassel <niklas.cas...@wdc.com>
> Signed-off-by: Hans Holmberg <hans.holmb...@wdc.com>
> Signed-off-by: Ajay Joshi <ajay.jo...@wdc.com>
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulka...@wdc.com>
> Signed-off-by: Matias Bjorling <matias.bjorl...@wdc.com>
> Signed-off-by: Aravind Ramesh <aravind.ram...@wdc.com>
> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawas...@wdc.com>
> Signed-off-by: Adam Manzanares <adam.manzana...@wdc.com>
> Signed-off-by: Dmitry Fomichev <dmitry.fomic...@wdc.com>
(snip)
> @@ -2260,6 +3155,11 @@ static void nvme_select_ns_iocs(NvmeCtrl *n)
> ns->iocs = nvme_cse_iocs_nvm;
> }
> break;
> + case NVME_CSI_ZONED:
> + if (NVME_CC_CSS(n->bar.cc) == NVME_CC_CSS_CSI) {
> + ns->iocs = nvme_cse_iocs_zoned;
> + }
> + break;
> }
> }
> }
Who knows how this whole command set mess is supposed to work,
since e.g. the Key Value Command Set assigns opcodes for new commands
(Delete, Exist) with a opcode values (0x10,0x14) smaller than the
current highest opcode value (0x15) in the NVM Command Set,
while those opcodes (0x10,0x14) are reserved in the NVM Command Set.
At least for Zoned Command Set, they defined the new commands
(Zone Mgmt Send, Zone Mgmt Recv) to opcode values (0x79,0x7a)
that are higher than the current highest opcode value in the
NVM Command Set.
So since we know that the Zoned Command Set is a strict superset of
the NVM Command Set, I guess it might be nice to do something like:
case NVME_CSI_ZONED:
if (NVME_CC_CSS(n->bar.cc) == NVME_CC_CSS_CSI) {
ns->iocs = nvme_cse_iocs_zoned;
} else if (NVME_CC_CSS(n->bar.cc) == NVME_CC_CSS_NVM) {
ns->iocs = nvme_cse_iocs_nvm;
}
break;
Since I assume that the spec people intended reads/writes
to a ZNS namespace to still be possible when CC_CSS == NVM,
but who knows?
Kind regards,
Niklas
