Re: [PATCH rdma-core v2 5/6] tests: Add tests for dma-buf based memory regions

[Yishai Hadas <yishaih@nvidia.com>]

On 11/24/2020 11:38 PM, Jianxin Xiong wrote:
> Define a full set of tests similar to regular MR tests. Add a utility
> function to generate access flags for dma-buf based MRs because the
> set of supported flags is smaller.


Looking on the tests, It doesn't seem that the registered dma-buf lkey 
is used with some RDMA traffic, right ?

Let's please use it in some test to cover a real use case of RDMA.

>
> Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
> ---
>   tests/test_mr.py | 130 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>   tests/utils.py   |  25 +++++++++++
>   2 files changed, 154 insertions(+), 1 deletion(-)
>
> diff --git a/tests/test_mr.py b/tests/test_mr.py
> index adc649c..8d7f002 100644
> --- a/tests/test_mr.py
> +++ b/tests/test_mr.py
> @@ -9,9 +9,10 @@ import errno
>   
>   from tests.base import PyverbsAPITestCase, RCResources, RDMATestCase
>   from pyverbs.pyverbs_error import PyverbsRDMAError, PyverbsError
> -from pyverbs.mr import MR, MW, DMMR, MWBindInfo, MWBind
> +from pyverbs.mr import MR, MW, DMMR, DmaBufMR, MWBindInfo, MWBind
>   from pyverbs.qp import QPCap, QPInitAttr, QPAttr, QP
>   from pyverbs.wr import SendWR
> +from pyverbs.dmabuf import DmaBuf
>   import pyverbs.device as d
>   from pyverbs.pd import PD
>   import pyverbs.enums as e
> @@ -366,3 +367,130 @@ class DMMRTest(PyverbsAPITestCase):
>                           dm_mr = DMMR(pd, dm_mr_len, e.IBV_ACCESS_ZERO_BASED,
>                                        dm=dm, offset=dm_mr_offset)
>                           dm_mr.close()
> +
> +class DmaBufMRTest(PyverbsAPITestCase):
> +    """
> +    Test various functionalities of the DmaBufMR class.
> +    """
> +    def test_dmabuf_reg_mr(self):
> +        """
> +        Test ibv_reg_dmabuf_mr()
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                flags = u.get_dmabuf_access_flags(ctx)
> +                for f in flags:
> +                    len = u.get_mr_length()
> +                    off = random.randint(0, len//2)
> +                    with DmaBufMR(pd, len, f, offset=off) as mr:
> +                        pass
> +
> +    def test_dmabuf_dereg_mr(self):
> +        """
> +        Test ibv_dereg_mr() with DmaBufMR
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                flags = u.get_dmabuf_access_flags(ctx)
> +                for f in flags:
> +                    len = u.get_mr_length()
> +                    off = random.randint(0, len//2)
> +                    with DmaBufMR(pd, len, f, offset=off) as mr:
> +                        mr.close()
> +
> +    def test_dmabuf_dereg_mr_twice(self):
> +        """
> +        Verify that explicit call to DmaBufMR's close() doesn't fail
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                flags = u.get_dmabuf_access_flags(ctx)
> +                for f in flags:
> +                    len = u.get_mr_length()
> +                    off = random.randint(0, len//2)
> +                    with DmaBufMR(pd, len, f, offset=off) as mr:
> +                        # Pyverbs supports multiple destruction of objects,
> +                        # we are not expecting an exception here.
> +                        mr.close()
> +                        mr.close()
> +
> +    def test_dmabuf_reg_mr_bad_flags(self):
> +        """
> +        Verify that illegal flags combination fails as expected
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                for i in range(5):
> +                    flags = random.sample([e.IBV_ACCESS_REMOTE_WRITE,
> +                                           e.IBV_ACCESS_REMOTE_ATOMIC],
> +                                          random.randint(1, 2))
> +                    mr_flags = 0
> +                    for i in flags:
> +                        mr_flags += i.value
> +                    try:
> +                        DmaBufMR(pd, u.get_mr_length(), mr_flags)
> +                    except PyverbsRDMAError as err:
> +                        assert 'Failed to register a dma-buf MR' in err.args[0]
> +                    else:
> +                        raise PyverbsRDMAError('Registered a dma-buf MR with illegal falgs')
> +
> +    def test_dmabuf_write(self):
> +        """
> +        Test writing to DmaBufMR's buffer
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                for i in range(10):
> +                    mr_len = u.get_mr_length()
> +                    mr_off = random.randint(0, mr_len//2)
> +                    flags = u.get_dmabuf_access_flags(ctx)
> +                    for f in flags:
> +                        with DmaBufMR(pd, mr_len, f, offset=mr_off) as mr:
> +                            write_len = min(random.randint(1, MAX_IO_LEN),
> +                                            mr_len)
> +                            mr.write('a' * write_len, write_len)
> +
> +    def test_dmabuf_read(self):
> +        """
> +        Test reading from DmaBufMR's buffer
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                for i in range(10):
> +                    mr_len = u.get_mr_length()
> +                    mr_off = random.randint(0, mr_len//2)
> +                    flags = u.get_dmabuf_access_flags(ctx)
> +                    for f in flags:
> +                        with DmaBufMR(pd, mr_len, f, offset=mr_off) as mr:
> +                            write_len = min(random.randint(1, MAX_IO_LEN),
> +                                            mr_len)
> +                            write_str = 'a' * write_len
> +                            mr.write(write_str, write_len)
> +                            read_len = random.randint(1, write_len)
> +                            offset = random.randint(0, write_len-read_len)
> +                            read_str = mr.read(read_len, offset).decode()
> +                            assert read_str in write_str
> +
> +    def test_dmabuf_lkey(self):
> +        """
> +        Test reading lkey property
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                length = u.get_mr_length()
> +                flags = u.get_dmabuf_access_flags(ctx)
> +                for f in flags:
> +                    with DmaBufMR(pd, length, f) as mr:
> +                        mr.lkey
> +
> +    def test_dmabuf_rkey(self):
> +        """
> +        Test reading rkey property
> +        """
> +        for ctx, attr, attr_ex in self.devices:
> +            with PD(ctx) as pd:
> +                length = u.get_mr_length()
> +                flags = u.get_dmabuf_access_flags(ctx)
> +                for f in flags:
> +                    with DmaBufMR(pd, length, f) as mr:
> +                        mr.rkey
> diff --git a/tests/utils.py b/tests/utils.py
> index 7039f41..0ad7110 100644
> --- a/tests/utils.py
> +++ b/tests/utils.py
> @@ -94,6 +94,31 @@ def get_access_flags(ctx):
>       return arr
>   
>   
> +def get_dmabuf_access_flags(ctx):
> +    """
> +    Similar to get_access_flags, except that dma-buf MR only support
> +    a subset of the flags.
> +    :param ctx: Device Context to check capabilities
> +    :return: A random legal value for MR flags
> +    """
> +    attr = ctx.query_device()
> +    vals = [e.IBV_ACCESS_LOCAL_WRITE, e.IBV_ACCESS_REMOTE_WRITE,
> +            e.IBV_ACCESS_REMOTE_READ, e.IBV_ACCESS_REMOTE_ATOMIC,
> +            e.IBV_ACCESS_RELAXED_ORDERING]
> +    if not attr.atomic_caps & e.IBV_ATOMIC_HCA:
> +        vals.remove(e.IBV_ACCESS_REMOTE_ATOMIC)
> +    arr = []
> +    for i in range(1, len(vals)):
> +        tmp = list(com(vals, i))
> +        tmp = filter(filter_illegal_access_flags, tmp)
> +        for t in tmp:  # Iterate legal combinations and bitwise OR them
> +            val = 0
> +            for flag in t:
> +                val += flag.value
> +            arr.append(val)
> +    return arr
> +
> +
>   def get_dm_attrs(dm_len):
>       """
>       Initializes an AllocDmAttr member with the given length and random