Re: [PATCH v2 14/18] hw/block/nvme: support identify namespace descriptor list

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 7/3/20 8:34 AM, Klaus Jensen wrote:
> From: Klaus Jensen <k.jensen@samsung.com>
> 
> Since we are not providing the NGUID or EUI64 fields, we must support
> the Namespace UUID. We do not have any way of storing a persistent
> unique identifier, so conjure up a UUID that is just the namespace id.
> 
> Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
> Reviewed-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>
> ---
>  hw/block/nvme.c       | 41 +++++++++++++++++++++++++++++++++++++++++
>  hw/block/trace-events |  1 +
>  2 files changed, 42 insertions(+)
> 
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 8230e0e3826b..65c2fa3ac1f4 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -971,6 +971,45 @@ static uint16_t nvme_identify_nslist(NvmeCtrl *n, NvmeIdentify *c)
>      return ret;
>  }
>  
> +static uint16_t nvme_identify_ns_descr_list(NvmeCtrl *n, NvmeIdentify *c)
> +{
> +    uint32_t nsid = le32_to_cpu(c->nsid);
> +    uint64_t prp1 = le64_to_cpu(c->prp1);
> +    uint64_t prp2 = le64_to_cpu(c->prp2);
> +
> +    uint8_t list[NVME_IDENTIFY_DATA_SIZE];
> +
> +    struct data {
> +        struct {
> +            NvmeIdNsDescr hdr;
> +            uint8_t v[16];

You might consider to use QemuUUID from "qemu/uuid.h". The benefits
are you can use qemu_uuid_parse() qemu_uuid_unparse*() for tracing,
and DEFINE_PROP_UUID() in case you want to set a particular UUID
from command line, it case it is important to the guest.

> +        } uuid;
> +    };
> +
> +    struct data *ns_descrs = (struct data *)list;
> +
> +    trace_pci_nvme_identify_ns_descr_list(nsid);
> +
> +    if (unlikely(nsid == 0 || nsid > n->num_namespaces)) {
> +        trace_pci_nvme_err_invalid_ns(nsid, n->num_namespaces);
> +        return NVME_INVALID_NSID | NVME_DNR;
> +    }
> +
> +    memset(list, 0x0, sizeof(list));
> +
> +    /*
> +     * Because the NGUID and EUI64 fields are 0 in the Identify Namespace data
> +     * structure, a Namespace UUID (nidt = 0x3) must be reported in the
> +     * Namespace Identification Descriptor. Add a very basic Namespace UUID
> +     * here.
> +     */
> +    ns_descrs->uuid.hdr.nidt = NVME_NIDT_UUID;
> +    ns_descrs->uuid.hdr.nidl = NVME_NIDT_UUID_LEN;
> +    stl_be_p(&ns_descrs->uuid.v, nsid);
> +
> +    return nvme_dma_read_prp(n, list, NVME_IDENTIFY_DATA_SIZE, prp1, prp2);
> +}
> +
>  static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
>  {
>      NvmeIdentify *c = (NvmeIdentify *)cmd;
> @@ -982,6 +1021,8 @@ static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
>          return nvme_identify_ctrl(n, c);
>      case NVME_ID_CNS_NS_ACTIVE_LIST:
>          return nvme_identify_nslist(n, c);
> +    case NVME_ID_CNS_NS_DESCR_LIST:
> +        return nvme_identify_ns_descr_list(n, c);
>      default:
>          trace_pci_nvme_err_invalid_identify_cns(le32_to_cpu(c->cns));
>          return NVME_INVALID_FIELD | NVME_DNR;
> diff --git a/hw/block/trace-events b/hw/block/trace-events
> index 4a4ef34071df..7b7303cab1dd 100644
> --- a/hw/block/trace-events
> +++ b/hw/block/trace-events
> @@ -45,6 +45,7 @@ pci_nvme_del_cq(uint16_t cqid) "deleted completion queue, cqid=%"PRIu16""
>  pci_nvme_identify_ctrl(void) "identify controller"
>  pci_nvme_identify_ns(uint32_t ns) "nsid %"PRIu32""
>  pci_nvme_identify_nslist(uint32_t ns) "nsid %"PRIu32""
> +pci_nvme_identify_ns_descr_list(uint32_t ns) "nsid %"PRIu32""
>  pci_nvme_get_log(uint16_t cid, uint8_t lid, uint8_t lsp, uint8_t rae, uint32_t len, uint64_t off) "cid %"PRIu16" lid 0x%"PRIx8" lsp 0x%"PRIx8" rae 0x%"PRIx8" len %"PRIu32" off %"PRIu64""
>  pci_nvme_getfeat(uint16_t cid, uint8_t fid, uint8_t sel, uint32_t cdw11) "cid %"PRIu16" fid 0x%"PRIx8" sel 0x%"PRIx8" cdw11 0x%"PRIx32""
>  pci_nvme_setfeat(uint16_t cid, uint8_t fid, uint8_t save, uint32_t cdw11) "cid %"PRIu16" fid 0x%"PRIx8" save 0x%"PRIx8" cdw11 0x%"PRIx32""
>