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

[Klaus Jensen]

On Sep 28 11:35, 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

The following looks like a rebase gone wrong.

There are some redundant checks and wrong return values.

>  static uint16_t nvme_identify_ns_descr_list(NvmeCtrl *n, NvmeRequest *req)
>  {
>      NvmeIdentify *c = (NvmeIdentify *)&req->cmd;
> +    NvmeNamespace *ns;
>      uint32_t nsid = le32_to_cpu(c->nsid);
> -    uint8_t list[NVME_IDENTIFY_DATA_SIZE];
> -
> -    struct data {
> -        struct {
> -            NvmeIdNsDescr hdr;
> -            uint8_t v[16];
> -        } uuid;
> -    };
> -
> -    struct data *ns_descrs = (struct data *)list;
> +    NvmeIdNsDescr *desc;
> +    uint8_t list[NVME_IDENTIFY_DATA_SIZE] = {};
> +    static const int data_len = sizeof(list);
> +    void *list_ptr = list;

Oh maaan, please do not replace my nicely cleaned up code with pointer
arithmetics :(

>  
>      trace_pci_nvme_identify_ns_descr_list(nsid);
>  
> -    if (!nvme_nsid_valid(n, nsid) || nsid == NVME_NSID_BROADCAST) {
> -        return NVME_INVALID_NSID | NVME_DNR;
> -    }
> -

This removal looks wrong.

>      if (unlikely(!nvme_ns(n, nsid))) {
>          return NVME_INVALID_FIELD | NVME_DNR;
>      }
>  
> -    memset(list, 0x0, sizeof(list));
> +    ns = nvme_ns(n, nsid);
> +    if (unlikely(!ns)) {
> +        return nvme_rpt_empty_id_struct(n, req);
> +    }
>  

And this doesnt look like it belongs (its checked just a few lines
before, and it returns an error status as it should).

>      /*
>       * Because the NGUID and EUI64 fields are 0 in the Identify Namespace 
> data
> @@ -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;
> +
> +    return nvme_dma(n, list, data_len, DMA_DIRECTION_FROM_DEVICE, req);
> +}
> +

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