Re: [PATCH v5 22/26] nvme: support multiple namespaces

[Keith Busch]

On Tue, Feb 04, 2020 at 10:52:04AM +0100, Klaus Jensen wrote:
> This adds support for multiple namespaces by introducing a new 'nvme-ns'
> device model. The nvme device creates a bus named from the device name
> ('id'). The nvme-ns devices then connect to this and registers
> themselves with the nvme device.
> 
> This changes how an nvme device is created. Example with two namespaces:
> 
>   -drive file=nvme0n1.img,if=none,id=disk1
>   -drive file=nvme0n2.img,if=none,id=disk2
>   -device nvme,serial=deadbeef,id=nvme0
>   -device nvme-ns,drive=disk1,bus=nvme0,nsid=1
>   -device nvme-ns,drive=disk2,bus=nvme0,nsid=2
> 
> The drive property is kept on the nvme device to keep the change
> backward compatible, but the property is now optional. Specifying a
> drive for the nvme device will always create the namespace with nsid 1.
> 
> Signed-off-by: Klaus Jensen <address@hidden>
> Signed-off-by: Klaus Jensen <address@hidden>

I like this feature a lot, thanks for doing it.

Reviewed-by: Keith Busch <address@hidden>

> @@ -1256,18 +1272,24 @@ static uint16_t nvme_smart_info(NvmeCtrl *n, NvmeCmd 
> *cmd, uint8_t rae,
>      uint64_t units_read = 0, units_written = 0, read_commands = 0,
>          write_commands = 0;
>      NvmeSmartLog smart;
> -    BlockAcctStats *s;
>  
>      if (nsid && nsid != 0xffffffff) {
>          return NVME_INVALID_FIELD | NVME_DNR;
>      }

This is totally optional, but worth mentioning: this patch makes it
possible to remove this check and allow per-namespace smart logs. The
ID_CTRL.LPA would need to updated to reflect that if you wanted to
go that route.