diff mbox series

[rdma-core,20/27] pyverbs/mlx5: Support more DevX objects

Message ID 20210720081647.1980-21-yishaih@nvidia.com (mailing list archive)
State Not Applicable
Headers show
Series Introduce mlx5 user space driver over VFIO | expand

Commit Message

Yishai Hadas July 20, 2021, 8:16 a.m. UTC
From: Edward Srouji <edwards@nvidia.com>

A DevX object represents some underlay firmware object, the input
command to create it is some raw data given by the user application
which should match the device specification.

A new class Mlx5DevxObj was added that would present any DevX object
that could be creating using the create_obj DevX API.
The command's output is stored in the object's instance, and the object
can be modified/queried and destroyed.

Reviewed-by: Ido Kalir <idok@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
---
 Documentation/pyverbs.md           |  34 ++++++++++++
 pyverbs/providers/mlx5/libmlx5.pxd |   7 +++
 pyverbs/providers/mlx5/mlx5dv.pxd  |   6 +++
 pyverbs/providers/mlx5/mlx5dv.pyx  | 103 ++++++++++++++++++++++++++++++++++++-
 4 files changed, 149 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/Documentation/pyverbs.md b/Documentation/pyverbs.md
index c7fa761..bcbde05 100644
--- a/Documentation/pyverbs.md
+++ b/Documentation/pyverbs.md
@@ -745,3 +745,37 @@  Below is the output when printing the spec.
     Dst mac         : de:de:de:00:de:de    mask: ff:ff:ff:ff:ff:ff
     Ether type      : 8451                 mask: 65535
     Vlan tag        : 8961                 mask: 65535
+
+
+##### MLX5 DevX Objects
+A DevX object represents some underlay firmware object, the input command to
+create it is some raw data given by the user application which should match the
+device specification.
+Upon successful creation, the output buffer includes the raw data from the device
+according to its specification and is stored in the Mlx5DevxObj instance. This
+data can be used as part of related firmware commands to this object.
+In addition to creation, the user can query/modify and destroy the object.
+
+Although weakrefs and DevX objects closure are added and handled by
+Pyverbs, the users must manually close these objects when finished, and
+should not let them be handled by the GC, or by closing the Mlx5Context directly,
+since there's no guarantee that the DevX objects are closed in the correct order,
+because Mlx5DevxObj is a general class that can be any of the device's available
+objects.
+But Pyverbs does guarantee to close DevX UARs and UMEMs in order, and after
+closing the other DevX objects.
+
+The following code snippet shows how to allocate and destroy a PD object over DevX.
+```python
+from pyverbs.providers.mlx5.mlx5dv import Mlx5Context, Mlx5DVContextAttr, Mlx5DevxObj
+import pyverbs.providers.mlx5.mlx5_enums as dve
+import struct
+
+attr = Mlx5DVContextAttr(dve.MLX5DV_CONTEXT_FLAGS_DEVX)
+ctx = Mlx5Context(attr, 'rocep8s0f0')
+MLX5_CMD_OP_ALLOC_PD = 0x800
+MLX5_CMD_OP_ALLOC_PD_OUTLEN = 0x10
+cmd_in = struct.pack('!H14s', MLX5_CMD_OP_ALLOC_PD, bytes(0))
+pd = Mlx5DevxObj(ctx, cmd_in, MLX5_CMD_OP_ALLOC_PD_OUTLEN)
+pd.close()
+```
diff --git a/pyverbs/providers/mlx5/libmlx5.pxd b/pyverbs/providers/mlx5/libmlx5.pxd
index ba2c6ec..34691a9 100644
--- a/pyverbs/providers/mlx5/libmlx5.pxd
+++ b/pyverbs/providers/mlx5/libmlx5.pxd
@@ -319,6 +319,13 @@  cdef extern from 'infiniband/mlx5dv.h':
                                               mlx5dv_devx_umem_in *umem_in)
     int mlx5dv_devx_umem_dereg(mlx5dv_devx_umem *umem)
     int mlx5dv_devx_query_eqn(v.ibv_context *context, uint32_t vector, uint32_t *eqn)
+    mlx5dv_devx_obj *mlx5dv_devx_obj_create(v.ibv_context *context, const void *_in,
+                                            size_t inlen, void *out, size_t outlen)
+    int mlx5dv_devx_obj_query(mlx5dv_devx_obj *obj, const void *in_,
+                              size_t inlen, void *out, size_t outlen)
+    int mlx5dv_devx_obj_modify(mlx5dv_devx_obj *obj, const void *in_,
+                               size_t inlen, void *out, size_t outlen)
+    int mlx5dv_devx_obj_destroy(mlx5dv_devx_obj *obj)
 
     # Mkey setters
     void mlx5dv_wr_mkey_configure(mlx5dv_qp_ex *mqp, mlx5dv_mkey *mkey,
diff --git a/pyverbs/providers/mlx5/mlx5dv.pxd b/pyverbs/providers/mlx5/mlx5dv.pxd
index 154a117..2b758fe 100644
--- a/pyverbs/providers/mlx5/mlx5dv.pxd
+++ b/pyverbs/providers/mlx5/mlx5dv.pxd
@@ -12,6 +12,7 @@  from pyverbs.cq cimport CQEX
 
 cdef class Mlx5Context(Context):
     cdef object devx_umems
+    cdef object devx_objs
     cdef add_ref(self, obj)
     cpdef close(self)
 
@@ -77,3 +78,8 @@  cdef class Mlx5UMEM(PyverbsCM):
     cdef Context context
     cdef void *addr
     cdef object is_user_addr
+
+cdef class Mlx5DevxObj(PyverbsCM):
+    cdef dv.mlx5dv_devx_obj *obj
+    cdef Context context
+    cdef object out_view
diff --git a/pyverbs/providers/mlx5/mlx5dv.pyx b/pyverbs/providers/mlx5/mlx5dv.pyx
index 2c47cb6..ab0bd4a 100644
--- a/pyverbs/providers/mlx5/mlx5dv.pyx
+++ b/pyverbs/providers/mlx5/mlx5dv.pyx
@@ -140,6 +140,104 @@  cdef class Mlx5DVContextAttr(PyverbsObject):
         self.attr.comp_mask = val
 
 
+cdef class Mlx5DevxObj(PyverbsCM):
+    """
+    Represents mlx5dv_devx_obj C struct.
+    """
+    def __init__(self, Context context, in_, outlen):
+        """
+        Creates a DevX object.
+        If the object was successfully created, the command's output would be
+        stored as a memoryview in self.out_view.
+        :param in_: Bytes of the obj_create command's input data provided in a
+                    device specification format.
+                    (Stream of bytes or __bytes__ is implemented)
+        :param outlen: Expected output length in bytes
+        """
+        super().__init__()
+        in_bytes = bytes(in_)
+        cdef char *in_mailbox = _prepare_devx_inbox(in_bytes)
+        cdef char *out_mailbox = _prepare_devx_outbox(outlen)
+        self.obj = dv.mlx5dv_devx_obj_create(context.context, in_mailbox,
+                                             len(in_bytes), out_mailbox, outlen)
+        try:
+            if self.obj == NULL:
+                raise PyverbsRDMAErrno('Failed to create DevX object')
+            self.out_view = memoryview(out_mailbox[:outlen])
+            status = hex(self.out_view[0])
+            syndrome = self.out_view[4:8].hex()
+            if status != hex(0):
+                raise PyverbsRDMAError('Failed to create DevX object with status'
+                                       f'({status}) and syndrome (0x{syndrome})')
+        finally:
+            free(in_mailbox)
+            free(out_mailbox)
+        self.context = context
+        self.context.add_ref(self)
+
+    def query(self, in_, outlen):
+        """
+        Queries the DevX object.
+        :param in_: Bytes of the obj_query command's input data provided in a
+                    device specification format.
+                    (Stream of bytes or __bytes__ is implemented)
+        :param outlen: Expected output length in bytes
+        :return: Bytes of the command's output
+        """
+        in_bytes = bytes(in_)
+        cdef char *in_mailbox = _prepare_devx_inbox(in_bytes)
+        cdef char *out_mailbox = _prepare_devx_outbox(outlen)
+        rc = dv.mlx5dv_devx_obj_query(self.obj, in_mailbox, len(in_bytes),
+                                      out_mailbox, outlen)
+        try:
+            if rc:
+                raise PyverbsRDMAError('Failed to query DevX object', rc)
+            out = <bytes>out_mailbox[:outlen]
+        finally:
+            free(in_mailbox)
+            free(out_mailbox)
+        return out
+
+    def modify(self, in_, outlen):
+        """
+        Modifies the DevX object.
+        :param in_: Bytes of the obj_modify command's input data provided in a
+                    device specification format.
+                    (Stream of bytes or __bytes__ is implemented)
+        :param outlen: Expected output length in bytes
+        :return: Bytes of the command's output
+        """
+        in_bytes = bytes(in_)
+        cdef char *in_mailbox = _prepare_devx_inbox(in_bytes)
+        cdef char *out_mailbox = _prepare_devx_outbox(outlen)
+        rc = dv.mlx5dv_devx_obj_modify(self.obj, in_mailbox, len(in_bytes),
+                                       out_mailbox, outlen)
+        try:
+            if rc:
+                raise PyverbsRDMAError('Failed to modify DevX object', rc)
+            out = <bytes>out_mailbox[:outlen]
+        finally:
+            free(in_mailbox)
+            free(out_mailbox)
+        return out
+
+    @property
+    def out_view(self):
+        return self.out_view
+
+    def __dealloc__(self):
+        self.close()
+
+    cpdef close(self):
+        if self.obj != NULL:
+            self.logger.debug('Closing Mlx5DvexObj')
+            rc = dv.mlx5dv_devx_obj_destroy(self.obj)
+            if rc:
+                raise PyverbsRDMAError('Failed to destroy a DevX object', rc)
+            self.obj = NULL
+            self.context = None
+
+
 cdef class Mlx5Context(Context):
     """
     Represent mlx5 context, which extends Context.
@@ -159,6 +257,7 @@  cdef class Mlx5Context(Context):
             raise PyverbsRDMAErrno('Failed to open mlx5 context on {dev}'
                                    .format(dev=self.name))
         self.devx_umems = weakref.WeakSet()
+        self.devx_objs = weakref.WeakSet()
 
     def query_mlx5_device(self, comp_mask=-1):
         """
@@ -280,6 +379,8 @@  cdef class Mlx5Context(Context):
         except PyverbsError:
             if isinstance(obj, Mlx5UMEM):
                 self.devx_umems.add(obj)
+            elif isinstance(obj, Mlx5DevxObj):
+                self.devx_objs.add(obj)
             else:
                 raise PyverbsError('Unrecognized object type')
 
@@ -288,7 +389,7 @@  cdef class Mlx5Context(Context):
 
     cpdef close(self):
         if self.context != NULL:
-            close_weakrefs([self.pps, self.devx_umems])
+            close_weakrefs([self.pps, self.devx_objs, self.devx_umems])
             super(Mlx5Context, self).close()