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Merge remote-tracking branch 'remotes/nvme/tags/nvme-fixes-20210412-p…
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…ull-request' into staging

emulated nvme docs and fixes for -rc3

- documentation
- fixes

# gpg: Signature made Mon 12 Apr 2021 07:56:09 BST
# gpg:                using RSA key 522833AA75E2DCE6A24766C04DE1AF316D4F0DE9
# gpg: Good signature from "Klaus Jensen <[email protected]>" [unknown]
# gpg:                 aka "Klaus Jensen <[email protected]>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: DDCA 4D9C 9EF9 31CC 3468  4272 63D5 6FC5 E55D A838
#      Subkey fingerprint: 5228 33AA 75E2 DCE6 A247  66C0 4DE1 AF31 6D4F 0DE9

* remotes/nvme/tags/nvme-fixes-20210412-pull-request:
  hw/block/nvme: drain namespaces on sq deletion
  hw/block/nvme: store aiocb in compare
  hw/block/nvme: map prp fix if prp2 contains non-zero offset
  docs: add nvme emulation documentation

Signed-off-by: Peter Maydell <[email protected]>
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2 changes: 1 addition & 1 deletion MAINTAINERS
Original file line number Diff line number Diff line change
Expand Up @@ -1974,7 +1974,7 @@ S: Supported
F: hw/block/nvme*
F: include/block/nvme.h
F: tests/qtest/nvme-test.c
F: docs/specs/nvme.txt
F: docs/system/nvme.rst
T: git git://git.infradead.org/qemu-nvme.git nvme-next

megasas
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23 changes: 0 additions & 23 deletions docs/specs/nvme.txt

This file was deleted.

1 change: 1 addition & 0 deletions docs/system/index.rst
Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@ Contents:
net
virtio-net-failover
usb
nvme
ivshmem
linuxboot
generic-loader
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225 changes: 225 additions & 0 deletions docs/system/nvme.rst
Original file line number Diff line number Diff line change
@@ -0,0 +1,225 @@
==============
NVMe Emulation
==============

QEMU provides NVMe emulation through the ``nvme``, ``nvme-ns`` and
``nvme-subsys`` devices.

See the following sections for specific information on

* `Adding NVMe Devices`_, `additional namespaces`_ and `NVM subsystems`_.
* Configuration of `Optional Features`_ such as `Controller Memory Buffer`_,
`Simple Copy`_, `Zoned Namespaces`_, `metadata`_ and `End-to-End Data
Protection`_,

Adding NVMe Devices
===================

Controller Emulation
--------------------

The QEMU emulated NVMe controller implements version 1.4 of the NVM Express
specification. All mandatory features are implement with a couple of exceptions
and limitations:

* Accounting numbers in the SMART/Health log page are reset when the device
is power cycled.
* Interrupt Coalescing is not supported and is disabled by default.

The simplest way to attach an NVMe controller on the QEMU PCI bus is to add the
following parameters:

.. code-block:: console
-drive file=nvm.img,if=none,id=nvm
-device nvme,serial=deadbeef,drive=nvm
There are a number of optional general parameters for the ``nvme`` device. Some
are mentioned here, but see ``-device nvme,help`` to list all possible
parameters.

``max_ioqpairs=UINT32`` (default: ``64``)
Set the maximum number of allowed I/O queue pairs. This replaces the
deprecated ``num_queues`` parameter.

``msix_qsize=UINT16`` (default: ``65``)
The number of MSI-X vectors that the device should support.

``mdts=UINT8`` (default: ``7``)
Set the Maximum Data Transfer Size of the device.

``use-intel-id`` (default: ``off``)
Since QEMU 5.2, the device uses a QEMU allocated "Red Hat" PCI Device and
Vendor ID. Set this to ``on`` to revert to the unallocated Intel ID
previously used.

Additional Namespaces
---------------------

In the simplest possible invocation sketched above, the device only support a
single namespace with the namespace identifier ``1``. To support multiple
namespaces and additional features, the ``nvme-ns`` device must be used.

.. code-block:: console
-device nvme,id=nvme-ctrl-0,serial=deadbeef
-drive file=nvm-1.img,if=none,id=nvm-1
-device nvme-ns,drive=nvm-1
-drive file=nvm-2.img,if=none,id=nvm-2
-device nvme-ns,drive=nvm-2
The namespaces defined by the ``nvme-ns`` device will attach to the most
recently defined ``nvme-bus`` that is created by the ``nvme`` device. Namespace
identifers are allocated automatically, starting from ``1``.

There are a number of parameters available:

``nsid`` (default: ``0``)
Explicitly set the namespace identifier.

``uuid`` (default: *autogenerated*)
Set the UUID of the namespace. This will be reported as a "Namespace UUID"
descriptor in the Namespace Identification Descriptor List.

``bus``
If there are more ``nvme`` devices defined, this parameter may be used to
attach the namespace to a specific ``nvme`` device (identified by an ``id``
parameter on the controller device).

NVM Subsystems
--------------

Additional features becomes available if the controller device (``nvme``) is
linked to an NVM Subsystem device (``nvme-subsys``).

The NVM Subsystem emulation allows features such as shared namespaces and
multipath I/O.

.. code-block:: console
-device nvme-subsys,id=nvme-subsys-0,nqn=subsys0
-device nvme,serial=a,subsys=nvme-subsys-0
-device nvme,serial=b,subsys=nvme-subsys-0
This will create an NVM subsystem with two controllers. Having controllers
linked to an ``nvme-subsys`` device allows additional ``nvme-ns`` parameters:

``shared`` (default: ``off``)
Specifies that the namespace will be attached to all controllers in the
subsystem. If set to ``off`` (the default), the namespace will remain a
private namespace and may only be attached to a single controller at a time.

``detached`` (default: ``off``)
If set to ``on``, the namespace will be be available in the subsystem, but
not attached to any controllers initially.

Thus, adding

.. code-block:: console
-drive file=nvm-1.img,if=none,id=nvm-1
-device nvme-ns,drive=nvm-1,nsid=1,shared=on
-drive file=nvm-2.img,if=none,id=nvm-2
-device nvme-ns,drive=nvm-2,nsid=3,detached=on
will cause NSID 1 will be a shared namespace (due to ``shared=on``) that is
initially attached to both controllers. NSID 3 will be a private namespace
(i.e. only attachable to a single controller at a time) and will not be
attached to any controller initially (due to ``detached=on``).

Optional Features
=================

Controller Memory Buffer
------------------------

``nvme`` device parameters related to the Controller Memory Buffer support:

``cmb_size_mb=UINT32`` (default: ``0``)
This adds a Controller Memory Buffer of the given size at offset zero in BAR
2.

``legacy-cmb`` (default: ``off``)
By default, the device uses the "v1.4 scheme" for the Controller Memory
Buffer support (i.e, the CMB is initially disabled and must be explicitly
enabled by the host). Set this to ``on`` to behave as a v1.3 device wrt. the
CMB.

Simple Copy
-----------

The device includes support for TP 4065 ("Simple Copy Command"). A number of
additional ``nvme-ns`` device parameters may be used to control the Copy
command limits:

``mssrl=UINT16`` (default: ``128``)
Set the Maximum Single Source Range Length (``MSSRL``). This is the maximum
number of logical blocks that may be specified in each source range.

``mcl=UINT32`` (default: ``128``)
Set the Maximum Copy Length (``MCL``). This is the maximum number of logical
blocks that may be specified in a Copy command (the total for all source
ranges).

``msrc=UINT8`` (default: ``127``)
Set the Maximum Source Range Count (``MSRC``). This is the maximum number of
source ranges that may be used in a Copy command. This is a 0's based value.

Zoned Namespaces
----------------

A namespaces may be "Zoned" as defined by TP 4053 ("Zoned Namespaces"). Set
``zoned=on`` on an ``nvme-ns`` device to configure it as a zoned namespace.

The namespace may be configured with additional parameters

``zoned.zone_size=SIZE`` (default: ``128MiB``)
Define the zone size (``ZSZE``).

``zoned.zone_capacity=SIZE`` (default: ``0``)
Define the zone capacity (``ZCAP``). If left at the default (``0``), the zone
capacity will equal the zone size.

``zoned.descr_ext_size=UINT32`` (default: ``0``)
Set the Zone Descriptor Extension Size (``ZDES``). Must be a multiple of 64
bytes.

``zoned.cross_read=BOOL`` (default: ``off``)
Set to ``on`` to allow reads to cross zone boundaries.

``zoned.max_active=UINT32`` (default: ``0``)
Set the maximum number of active resources (``MAR``). The default (``0``)
allows all zones to be active.

``zoned.max_open=UINT32`` (default: ``0``)
Set the maximum number of open resources (``MOR``). The default (``0``)
allows all zones to be open. If ``zoned.max_active`` is specified, this value
must be less than or equal to that.

Metadata
--------

The virtual namespace device supports LBA metadata in the form separate
metadata (``MPTR``-based) and extended LBAs.

``ms=UINT16`` (default: ``0``)
Defines the number of metadata bytes per LBA.

``mset=UINT8`` (default: ``0``)
Set to ``1`` to enable extended LBAs.

End-to-End Data Protection
--------------------------

The virtual namespace device supports DIF- and DIX-based protection information
(depending on ``mset``).

``pi=UINT8`` (default: ``0``)
Enable protection information of the specified type (type ``1``, ``2`` or
``3``).

``pil=UINT8`` (default: ``0``)
Controls the location of the protection information within the metadata. Set
to ``1`` to transfer protection information as the first eight bytes of
metadata. Otherwise, the protection information is transferred as the last
eight bytes.
38 changes: 32 additions & 6 deletions hw/block/nvme.c
Original file line number Diff line number Diff line change
Expand Up @@ -470,6 +470,7 @@ static void nvme_req_clear(NvmeRequest *req)
{
req->ns = NULL;
req->opaque = NULL;
req->aiocb = NULL;
memset(&req->cqe, 0x0, sizeof(req->cqe));
req->status = NVME_SUCCESS;
}
Expand Down Expand Up @@ -655,7 +656,12 @@ static uint16_t nvme_map_prp(NvmeCtrl *n, NvmeSg *sg, uint64_t prp1,
uint32_t nents, prp_trans;
int i = 0;

nents = (len + n->page_size - 1) >> n->page_bits;
/*
* The first PRP list entry, pointed to by PRP2 may contain offset.
* Hence, we need to calculate the number of entries in based on
* that offset.
*/
nents = (n->page_size - (prp2 & (n->page_size - 1))) >> 3;
prp_trans = MIN(n->max_prp_ents, nents) * sizeof(uint64_t);
ret = nvme_addr_read(n, prp2, (void *)prp_list, prp_trans);
if (ret) {
Expand All @@ -666,7 +672,7 @@ static uint16_t nvme_map_prp(NvmeCtrl *n, NvmeSg *sg, uint64_t prp1,
while (len != 0) {
uint64_t prp_ent = le64_to_cpu(prp_list[i]);

if (i == n->max_prp_ents - 1 && len > n->page_size) {
if (i == nents - 1 && len > n->page_size) {
if (unlikely(prp_ent & (n->page_size - 1))) {
trace_pci_nvme_err_invalid_prplist_ent(prp_ent);
status = NVME_INVALID_PRP_OFFSET | NVME_DNR;
Expand All @@ -675,7 +681,8 @@ static uint16_t nvme_map_prp(NvmeCtrl *n, NvmeSg *sg, uint64_t prp1,

i = 0;
nents = (len + n->page_size - 1) >> n->page_bits;
prp_trans = MIN(n->max_prp_ents, nents) * sizeof(uint64_t);
nents = MIN(nents, n->max_prp_ents);
prp_trans = nents * sizeof(uint64_t);
ret = nvme_addr_read(n, prp_ent, (void *)prp_list,
prp_trans);
if (ret) {
Expand Down Expand Up @@ -2837,7 +2844,8 @@ static uint16_t nvme_compare(NvmeCtrl *n, NvmeRequest *req)

block_acct_start(blk_get_stats(blk), &req->acct, data_len,
BLOCK_ACCT_READ);
blk_aio_preadv(blk, offset, &ctx->data.iov, 0, nvme_compare_data_cb, req);
req->aiocb = blk_aio_preadv(blk, offset, &ctx->data.iov, 0,
nvme_compare_data_cb, req);

return NVME_NO_COMPLETE;
}
Expand Down Expand Up @@ -3680,6 +3688,7 @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeRequest *req)
NvmeSQueue *sq;
NvmeCQueue *cq;
uint16_t qid = le16_to_cpu(c->qid);
uint32_t nsid;

if (unlikely(!qid || nvme_check_sqid(n, qid))) {
trace_pci_nvme_err_invalid_del_sq(qid);
Expand All @@ -3691,9 +3700,26 @@ static uint16_t nvme_del_sq(NvmeCtrl *n, NvmeRequest *req)
sq = n->sq[qid];
while (!QTAILQ_EMPTY(&sq->out_req_list)) {
r = QTAILQ_FIRST(&sq->out_req_list);
assert(r->aiocb);
blk_aio_cancel(r->aiocb);
if (r->aiocb) {
blk_aio_cancel(r->aiocb);
}
}

/*
* Drain all namespaces if there are still outstanding requests that we
* could not cancel explicitly.
*/
if (!QTAILQ_EMPTY(&sq->out_req_list)) {
for (nsid = 1; nsid <= NVME_MAX_NAMESPACES; nsid++) {
NvmeNamespace *ns = nvme_ns(n, nsid);
if (ns) {
nvme_ns_drain(ns);
}
}
}

assert(QTAILQ_EMPTY(&sq->out_req_list));

if (!nvme_check_cqid(n, sq->cqid)) {
cq = n->cq[sq->cqid];
QTAILQ_REMOVE(&cq->sq_list, sq, entry);
Expand Down

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