Re: [PATCH v5 05/14] hw/block/nvme: Add support for Namespace Types

[Niklas Cassel <Niklas.Cassel@wdc.com>]

On Mon, Sep 28, 2020 at 11:35:19AM +0900, Dmitry Fomichev wrote:
> From: Niklas Cassel <niklas.cassel@wdc.com>
> 
> Namespace Types introduce a new command set, "I/O Command Sets",
> that allows the host to retrieve the command sets associated with
> a namespace. Introduce support for the command set and enable
> detection for the NVM Command Set.
> 
> The new workflows for identify commands rely heavily on zero-filled
> identify structs. E.g., certain CNS commands are defined to return
> a zero-filled identify struct when an inactive namespace NSID
> is supplied.
> 
> Add a helper function in order to avoid code duplication when
> reporting zero-filled identify structures.
> 
> Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
> ---
>  hw/block/nvme-ns.c |   3 +
>  hw/block/nvme.c    | 210 +++++++++++++++++++++++++++++++++++++--------
>  2 files changed, 175 insertions(+), 38 deletions(-)
> 
> diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
> index bbd7879492..31b7f986c3 100644
> --- a/hw/block/nvme-ns.c
> +++ b/hw/block/nvme-ns.c

(snip)

> @@ -1597,12 +1667,31 @@ static uint16_t nvme_identify_ns_descr_list(NvmeCtrl *n, NvmeRequest *req)
>       * Namespace Identification Descriptor. Add a very basic Namespace UUID
>       * here.
>       */
> -    ns_descrs->uuid.hdr.nidt = NVME_NIDT_UUID;
> -    ns_descrs->uuid.hdr.nidl = NVME_NIDL_UUID;
> -    stl_be_p(&ns_descrs->uuid.v, nsid);
> +    desc = list_ptr;
> +    desc->nidt = NVME_NIDT_UUID;
> +    desc->nidl = NVME_NIDL_UUID;
> +    list_ptr += sizeof(*desc);
> +    memcpy(list_ptr, ns->params.uuid.data, NVME_NIDL_UUID);
> +    list_ptr += NVME_NIDL_UUID;
>  
> -    return nvme_dma(n, list, NVME_IDENTIFY_DATA_SIZE,
> -                    DMA_DIRECTION_FROM_DEVICE, req);
> +    desc = list_ptr;
> +    desc->nidt = NVME_NIDT_CSI;
> +    desc->nidl = NVME_NIDL_CSI;
> +    list_ptr += sizeof(*desc);
> +    *(uint8_t *)list_ptr = NVME_CSI_NVM;

I think that we should use ns->csi/ns->params.csi here rather than
NVME_CSI_NVM.
You do this change in a later patch, but I think it is more correct
to do it here already. (No reason not to, since ns->csi/ns->params.csi
should be set to NVME_CSI_NVM for NVM namespace already in this patch.)

> +
> +    return nvme_dma(n, list, data_len, DMA_DIRECTION_FROM_DEVICE, req);
> +}