Re: [PATCH v2 12/18] hw/block/nvme: Simulate Zone Active excursions

[Alistair Francis <alistair23@gmail.com>]

On Wed, Jun 17, 2020 at 2:52 PM Dmitry Fomichev <dmitry.fomichev@wdc.com> wrote:
>
> Added a Boolean flag to turn on simulation of Zone Active Excursions.
> If the flag, "active_excursions", is set to true, the driver will try
> to finish one of the currently open zone if max active zones limit is
> going to get exceeded.
>
> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@wdc.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  hw/block/nvme.c | 24 +++++++++++++++++++++++-
>  hw/block/nvme.h |  1 +
>  2 files changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 05a7cbcfcc..a29cbfcc96 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -540,6 +540,26 @@ static void nvme_auto_transition_zone(NvmeCtrl *n, NvmeNamespace *ns,
>  {
>      NvmeZone *zone;
>
> +    if (n->params.active_excursions && adding_active &&
> +        n->params.max_active_zones &&
> +        ns->nr_active_zones == n->params.max_active_zones) {
> +        zone = nvme_peek_zone_head(ns, ns->closed_zones);
> +        if (zone) {
> +            /*
> +             * The namespace is at the limit of active zones.
> +             * Try to finish one of the currently active zones
> +             * to make the needed active zone resource available.
> +             */
> +            nvme_aor_dec_active(n, ns);
> +            nvme_assign_zone_state(n, ns, zone, NVME_ZONE_STATE_FULL);
> +            zone->d.za &= ~(NVME_ZA_FINISH_RECOMMENDED |
> +                            NVME_ZA_RESET_RECOMMENDED);
> +            zone->d.za |= NVME_ZA_FINISHED_BY_CTLR;
> +            zone->tstamp = 0;
> +            trace_pci_nvme_zone_finished_by_controller(zone->d.zslba);
> +        }
> +    }
> +
>      if (implicit && n->params.max_open_zones &&
>          ns->nr_open_zones == n->params.max_open_zones) {
>          zone = nvme_remove_zone_head(n, ns, ns->imp_open_zones);
> @@ -2631,7 +2651,7 @@ static int nvme_zoned_init_ns(NvmeCtrl *n, NvmeNamespace *ns, int lba_index,
>      /* MAR/MOR are zeroes-based, 0xffffffff means no limit */
>      ns->id_ns_zoned->mar = cpu_to_le32(n->params.max_active_zones - 1);
>      ns->id_ns_zoned->mor = cpu_to_le32(n->params.max_open_zones - 1);
> -    ns->id_ns_zoned->zoc = 0;
> +    ns->id_ns_zoned->zoc = cpu_to_le16(n->params.active_excursions ? 0x2 : 0);
>      ns->id_ns_zoned->ozcs = n->params.cross_zone_read ? 0x01 : 0x00;
>
>      ns->id_ns_zoned->lbafe[lba_index].zsze = cpu_to_le64(n->params.zone_size);
> @@ -2993,6 +3013,8 @@ static Property nvme_props[] = {
>      DEFINE_PROP_INT32("max_active", NvmeCtrl, params.max_active_zones, 0),
>      DEFINE_PROP_INT32("max_open", NvmeCtrl, params.max_open_zones, 0),
>      DEFINE_PROP_BOOL("cross_zone_read", NvmeCtrl, params.cross_zone_read, true),
> +    DEFINE_PROP_BOOL("active_excursions", NvmeCtrl, params.active_excursions,
> +                     false),
>      DEFINE_PROP_UINT8("fill_pattern", NvmeCtrl, params.fill_pattern, 0),
>      DEFINE_PROP_END_OF_LIST(),
>  };
> diff --git a/hw/block/nvme.h b/hw/block/nvme.h
> index f5a4679702..8a0aaeb09a 100644
> --- a/hw/block/nvme.h
> +++ b/hw/block/nvme.h
> @@ -15,6 +15,7 @@ typedef struct NvmeParams {
>
>      bool        zoned;
>      bool        cross_zone_read;
> +    bool        active_excursions;
>      uint8_t     fill_pattern;
>      uint32_t    zamds_bs;
>      uint64_t    zone_size;
> --
> 2.21.0
>
>