Re: [PATCH V6 6/6] hw/block/nvme: support for shared namespace in subsystem

From: Klaus Jensen <its@irrelevant.dk>
To: Minwoo Im <minwoo.im.dev@gmail.com>
Cc: Keith Busch <kbusch@kernel.org>, Kevin Wolf <kwolf@redhat.com>,
	qemu-devel@nongnu.org, qemu-block@nongnu.org,
	Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH V6 6/6] hw/block/nvme: support for shared namespace in subsystem
Date: Mon, 25 Jan 2021 20:53:11 +0100	[thread overview]
Message-ID: <YA8hp7keD+G9uE+8@apples.localdomain> (raw)
In-Reply-To: <20210124025450.11071-7-minwoo.im.dev@gmail.com>

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On Jan 24 11:54, Minwoo Im wrote:
> nvme-ns device is registered to a nvme controller device during the
> initialization in nvme_register_namespace() in case that 'bus' property
> is given which means it's mapped to a single controller.
> 
> This patch introduced a new property 'subsys' just like the controller
> device instance did to map a namespace to a NVMe subsystem.
> 
> If 'subsys' property is given to the nvme-ns device, it will belong to
> the specified subsystem and will be attached to all controllers in that
> subsystem by enabling shared namespace capability in NMIC(Namespace
> Multi-path I/O and Namespace Capabilities) in Identify Namespace.
> 
> Usage:
> 
>   -device nvme-subsys,id=subsys0
>   -device nvme,serial=foo,id=nvme0,subsys=subsys0
>   -device nvme,serial=bar,id=nvme1,subsys=subsys0
>   -device nvme,serial=baz,id=nvme2,subsys=subsys0
>   -device nvme-ns,id=ns1,drive=<drv>,nsid=1,subsys=subsys0  # Shared
>   -device nvme-ns,id=ns2,drive=<drv>,nsid=2,bus=nvme2       # Non-shared
> 
>   In the above example, 'ns1' will be shared to 'nvme0' and 'nvme1' in
>   the same subsystem.  On the other hand, 'ns2' will be attached to the
>   'nvme2' only as a private namespace in that subsystem.
> 
> All the namespace with 'subsys' parameter will attach all controllers in
> the subsystem to the namespace by default.
> 
> Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
> ---
>  hw/block/nvme-ns.c     | 23 ++++++++++++++++++-----
>  hw/block/nvme-ns.h     |  7 +++++++
>  hw/block/nvme-subsys.c | 25 +++++++++++++++++++++++++
>  hw/block/nvme-subsys.h |  3 +++
>  hw/block/nvme.c        | 10 +++++++++-
>  5 files changed, 62 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/block/nvme-ns.c b/hw/block/nvme-ns.c
> index 62b25cf69bfa..9b493f2ead03 100644
> --- a/hw/block/nvme-ns.c
> +++ b/hw/block/nvme-ns.c
> @@ -63,6 +63,10 @@ static int nvme_ns_init(NvmeNamespace *ns, Error **errp)
>  
>      id_ns->npda = id_ns->npdg = npdg - 1;
>  
> +    if (nvme_ns_shared(ns)) {
> +        id_ns->nmic |= NVME_NMIC_NS_SHARED;
> +    }
> +
>      return 0;
>  }
>  
> @@ -365,16 +369,25 @@ static void nvme_ns_realize(DeviceState *dev, Error **errp)
>          return;
>      }
>  
> -    if (nvme_register_namespace(n, ns, errp)) {
> -        error_propagate_prepend(errp, local_err,
> -                                "could not register namespace: ");
> -        return;
> +    if (ns->subsys) {
> +        if (nvme_subsys_register_ns(ns, errp)) {
> +            error_propagate_prepend(errp, local_err,
> +                                    "could not setup namespace to subsys: ");
> +            return;
> +        }
> +    } else {
> +        if (nvme_register_namespace(n, ns, errp)) {
> +            error_propagate_prepend(errp, local_err,
> +                                    "could not register namespace: ");
> +            return;
> +        }
>      }
> -
>  }
>  
>  static Property nvme_ns_props[] = {
>      DEFINE_BLOCK_PROPERTIES(NvmeNamespace, blkconf),
> +    DEFINE_PROP_LINK("subsys", NvmeNamespace, subsys, TYPE_NVME_SUBSYS,
> +                     NvmeSubsystem *),
>      DEFINE_PROP_UINT32("nsid", NvmeNamespace, params.nsid, 0),
>      DEFINE_PROP_UUID("uuid", NvmeNamespace, params.uuid),
>      DEFINE_PROP_BOOL("zoned", NvmeNamespace, params.zoned, false),
> diff --git a/hw/block/nvme-ns.h b/hw/block/nvme-ns.h
> index 293ac990e3f6..929e78861903 100644
> --- a/hw/block/nvme-ns.h
> +++ b/hw/block/nvme-ns.h
> @@ -47,6 +47,8 @@ typedef struct NvmeNamespace {
>      const uint32_t *iocs;
>      uint8_t      csi;
>  
> +    NvmeSubsystem   *subsys;
> +
>      NvmeIdNsZoned   *id_ns_zoned;
>      NvmeZone        *zone_array;
>      QTAILQ_HEAD(, NvmeZone) exp_open_zones;
> @@ -77,6 +79,11 @@ static inline uint32_t nvme_nsid(NvmeNamespace *ns)
>      return -1;
>  }
>  
> +static inline bool nvme_ns_shared(NvmeNamespace *ns)
> +{
> +    return !!ns->subsys;
> +}
> +
>  static inline NvmeLBAF *nvme_ns_lbaf(NvmeNamespace *ns)
>  {
>      NvmeIdNs *id_ns = &ns->id_ns;
> diff --git a/hw/block/nvme-subsys.c b/hw/block/nvme-subsys.c
> index e9d61c993c90..641de33e99fc 100644
> --- a/hw/block/nvme-subsys.c
> +++ b/hw/block/nvme-subsys.c
> @@ -43,6 +43,31 @@ int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp)
>      return cntlid;
>  }
>  
> +int nvme_subsys_register_ns(NvmeNamespace *ns, Error **errp)
> +{
> +    NvmeSubsystem *subsys = ns->subsys;
> +    NvmeCtrl *n;
> +    int i;
> +
> +    if (subsys->namespaces[nvme_nsid(ns)]) {
> +        error_setg(errp, "namespace %d already registerd to subsy %s",

Small typo.

"registerEd to subsySTEM"

> +                   nvme_nsid(ns), subsys->parent_obj.id);
> +        return -1;
> +    }
> +
> +    subsys->namespaces[nvme_nsid(ns)] = ns;
> +
> +    for (i = 0; i < ARRAY_SIZE(subsys->ctrls); i++) {
> +        n = subsys->ctrls[i];
> +
> +        if (n && nvme_register_namespace(n, ns, errp)) {
> +            return -1;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
>  static void nvme_subsys_setup(NvmeSubsystem *subsys)
>  {
>      snprintf((char *)subsys->subnqn, sizeof(subsys->subnqn),
> diff --git a/hw/block/nvme-subsys.h b/hw/block/nvme-subsys.h
> index 4eba50d96a1d..ccf6a71398d3 100644
> --- a/hw/block/nvme-subsys.h
> +++ b/hw/block/nvme-subsys.h
> @@ -14,6 +14,7 @@
>      OBJECT_CHECK(NvmeSubsystem, (obj), TYPE_NVME_SUBSYS)
>  
>  #define NVME_SUBSYS_MAX_CTRLS   32
> +#define NVME_SUBSYS_MAX_NAMESPACES  32
>  
>  typedef struct NvmeCtrl NvmeCtrl;
>  typedef struct NvmeNamespace NvmeNamespace;
> @@ -22,8 +23,10 @@ typedef struct NvmeSubsystem {
>      uint8_t     subnqn[256];
>  
>      NvmeCtrl    *ctrls[NVME_SUBSYS_MAX_CTRLS];
> +    NvmeNamespace *namespaces[NVME_SUBSYS_MAX_NAMESPACES];
>  } NvmeSubsystem;
>  
>  int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp);
> +int nvme_subsys_register_ns(NvmeNamespace *ns, Error **errp);
>  
>  #endif /* NVME_SUBSYS_H */
> diff --git a/hw/block/nvme.c b/hw/block/nvme.c
> index 7138389be4bd..8259dbf48ec0 100644
> --- a/hw/block/nvme.c
> +++ b/hw/block/nvme.c
> @@ -25,7 +25,8 @@
>   *              mdts=<N[optional]>,zoned.append_size_limit=<N[optional]>, \
>   *              subsys=<subsys_id> \
>   *      -device nvme-ns,drive=<drive_id>,bus=<bus_name>,nsid=<nsid>,\
> - *              zoned=<true|false[optional]>
> + *              zoned=<true|false[optional]>, \
> + *              subsys=<subsys_id>
>   *      -device nvme-subsys,id=<subsys_id>
>   *
>   * Note cmb_size_mb denotes size of CMB in MB. CMB is assumed to be at
> @@ -70,6 +71,13 @@
>   *   data size being in effect. By setting this property to 0, users can make
>   *   ZASL to be equal to MDTS. This property only affects zoned namespaces.
>   *
> + * nvme namespace device parameters
> + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> + * - `subsys`
> + *   NVM Subsystem device.  If given, this namespace will be attached to all
> + *   controllers in the subsystem. Otherwise, `bus` must be given to attach
> + *   this namespace to a specified single controller as a non-shared namespace.
> + *
>   * Setting `zoned` to true selects Zoned Command Set at the namespace.
>   * In this case, the following namespace properties are available to configure
>   * zoned operation:
> -- 
> 2.17.1
> 

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