This commit reverts commit 7afbddfae9 ("IB/core: Temporarily disable
create_flow/destroy_flow uverbs"). Since the uverbs extensions
functionality was experimental for v3.12, this patch re-enables the
support for them and flow-steering for v3.13.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Commit 400dbc9658 ("IB/core: Infrastructure for extensible uverbs
commands") added an infrastructure for extensible uverbs commands
while later commit 436f2ad05a ("IB/core: Export ib_create/destroy_flow
through uverbs") exported ib_create_flow()/ib_destroy_flow() functions
using this new infrastructure.
According to the commit 400dbc9658, the purpose of this
infrastructure is to support passing around provider (eg. hardware)
specific buffers when userspace issue commands to the kernel, so that
it would be possible to extend uverbs (eg. core) buffers independently
from the provider buffers.
But the new kernel command function prototypes were not modified to
take advantage of this extension. This issue was exposed by Roland
Dreier in a previous review[1].
So the following patch is an attempt to a revised extensible command
infrastructure.
This improved extensible command infrastructure distinguish between
core (eg. legacy)'s command/response buffers from provider
(eg. hardware)'s command/response buffers: each extended command
implementing function is given a struct ib_udata to hold core
(eg. uverbs) input and output buffers, and another struct ib_udata to
hold the hw (eg. provider) input and output buffers.
Having those buffers identified separately make it easier to increase
one buffer to support extension without having to add some code to
guess the exact size of each command/response parts: This should make
the extended functions more reliable.
Additionally, instead of relying on command identifier being greater
than IB_USER_VERBS_CMD_THRESHOLD, the proposed infrastructure rely on
unused bits in command field: on the 32 bits provided by command
field, only 6 bits are really needed to encode the identifier of
commands currently supported by the kernel. (Even using only 6 bits
leaves room for about 23 new commands).
So this patch makes use of some high order bits in command field to
store flags, leaving enough room for more command identifiers than one
will ever need (eg. 256).
The new flags are used to specify if the command should be processed
as an extended one or a legacy one. While designing the new command
format, care was taken to make usage of flags itself extensible.
Using high order bits of the commands field ensure that newer
libibverbs on older kernel will properly fail when trying to call
extended commands. On the other hand, older libibverbs on newer kernel
will never be able to issue calls to extended commands.
The extended command header includes the optional response pointer so
that output buffer length and output buffer pointer are located
together in the command, allowing proper parameters checking. This
should make implementing functions easier and safer.
Additionally the extended header ensure 64bits alignment, while making
all sizes multiple of 8 bytes, extending the maximum buffer size:
legacy extended
Maximum command buffer: 256KBytes 1024KBytes (512KBytes + 512KBytes)
Maximum response buffer: 256KBytes 1024KBytes (512KBytes + 512KBytes)
For the purpose of doing proper buffer size accounting, the headers
size are no more taken in account in "in_words".
One of the odds of the current extensible infrastructure, reading
twice the "legacy" command header, is fixed by removing the "legacy"
command header from the extended command header: they are processed as
two different parts of the command: memory is read once and
information are not duplicated: it's making clear that's an extended
command scheme and not a different command scheme.
The proposed scheme will format input (command) and output (response)
buffers this way:
- command:
legacy header +
extended header +
command data (core + hw):
+----------------------------------------+
| flags | 00 00 | command |
| in_words | out_words |
+----------------------------------------+
| response |
| response |
| provider_in_words | provider_out_words |
| padding |
+----------------------------------------+
| |
. <uverbs input> .
. (in_words * 8) .
| |
+----------------------------------------+
| |
. <provider input> .
. (provider_in_words * 8) .
| |
+----------------------------------------+
- response, if present:
+----------------------------------------+
| |
. <uverbs output space> .
. (out_words * 8) .
| |
+----------------------------------------+
| |
. <provider output space> .
. (provider_out_words * 8) .
| |
+----------------------------------------+
The overall design is to ensure that the extensible infrastructure is
itself extensible while begin more reliable with more input and bound
checking.
Note:
The unused field in the extended header would be perfect candidate to
hold the command "comp_mask" (eg. bit field used to handle
compatibility). This was suggested by Roland Dreier in a previous
review[2]. But "comp_mask" field is likely to be present in the uverb
input and/or provider input, likewise for the response, as noted by
Matan Barak[3], so it doesn't make sense to put "comp_mask" in the
header.
[1]:
http://marc.info/?i=CAL1RGDWxmM17W2o_era24A-TTDeKyoL6u3NRu_=t_dhV_ZA9MA@mail.gmail.com
[2]:
http://marc.info/?i=CAL1RGDXJtrc849M6_XNZT5xO1+ybKtLWGq6yg6LhoSsKpsmkYA@mail.gmail.com
[3]:
http://marc.info/?i=525C1149.6000701@mellanox.com
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://marc.info/?i=cover.1383773832.git.ydroneaud@opteya.com
[ Convert "ret ? ret : 0" to the equivalent "ret". - Roland ]
Signed-off-by: Roland Dreier <roland@purestorage.com>
The structure holding any types of flow_spec is of no use to
userspace. It would be wrong for userspace to do:
struct ib_uverbs_flow_spec flow_spec;
flow_spec.type = IB_FLOW_SPEC_TCP;
flow_spec.size = sizeof(flow_spec);
Instead, userspace should use the dedicated flow_spec structure for
- Ethernet : struct ib_uverbs_flow_spec_eth,
- IPv4 : struct ib_uverbs_flow_spec_ipv4,
- TCP/UDP : struct ib_uverbs_flow_spec_tcp_udp.
In other words, struct ib_uverbs_flow_spec is a "virtual" data
structure that can only be use by the kernel as an alias to the other.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://marc.info/?i=cover.1383773832.git.ydroneaud@opteya.com
Signed-off-by: Roland Dreier <roland@purestorage.com>
A common header will allows better checking of flow specs size, while
ensuring strict alignment to 64 bits.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://marc.info/?i=cover.1383773832.git.ydroneaud@opteya.com
Signed-off-by: Roland Dreier <roland@purestorage.com>
This patch adds "flow" prefix to most of data structure added as part
of commit 436f2ad05a ("IB/core: Export ib_create/destroy_flow through
uverbs") to keep those names in sync with the data structures added in
commit 319a441d13 ("IB/core: Add receive flow steering support").
It's just a matter of translating 'ib_flow' to 'ib_uverbs_flow'.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://marc.info/?i=cover.1383773832.git.ydroneaud@opteya.com
Signed-off-by: Roland Dreier <roland@purestorage.com>
Commit 436f2ad05a ("IB/core: Export ib_create/destroy_flow through
uverbs") added public data structures to support receive flow
steering. The new structs are not following the 'uverbs' pattern:
they're lacking the common prefix 'ib_uverbs'.
This patch replaces ib_kern prefix by ib_uverbs.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://marc.info/?i=cover.1383773832.git.ydroneaud@opteya.com
Signed-off-by: Roland Dreier <roland@purestorage.com>
This patch fixes the following issues:
1. Unneeded checks were removed
2. Removed the fixed size out of flow_attr.size, thus simplifying the checks.
3. Remove a 32bit hole on 64bit systems with strict alignment in
struct ib_kern_flow_att by adding a reserved field.
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The create_flow/destroy_flow uverbs and the associated extensions to
the user-kernel verbs ABI are under review and are too experimental to
freeze at this point.
So userspace is not exposed to experimental features and an uinstable
ABI, temporarily disable this for v3.12 (with a Kconfig option behind
staging to reenable it if desired).
The feature will be enabled after proper cleanup for v3.13.
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Link: http://marc.info/?i=cover.1381351016.git.ydroneaud@opteya.com
Link: http://marc.info/?i=cover.1381177342.git.ydroneaud@opteya.com
[ Add a Kconfig option to reenable these verbs. - Roland ]
Signed-off-by: Roland Dreier <roland@purestorage.com>
Implement ib_uverbs_create_flow() and ib_uverbs_destroy_flow() to
support flow steering for user space applications.
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Add infrastructure to support extended uverbs capabilities in a
forward/backward manner. Uverbs command opcodes which are based on
the verbs extensions approach should be greater or equal to
IB_USER_VERBS_CMD_THRESHOLD. They have new header format and
processed a bit differently.
Whenever a specific IB_USER_VERBS_CMD_XXX is extended, which practically means
it needs to have additional arguments, we will be able to add them without creating
a completely new IB_USER_VERBS_CMD_YYY command or bumping the uverbs ABI version.
This patch for itself doesn't provide the whole scheme which is also dependent
on adding a comp_mask field to each extended uverbs command struct.
The new header framework allows for future extension of the CMD arguments
(ib_uverbs_cmd_hdr.in_words, ib_uverbs_cmd_hdr.out_words) for an existing
new command (that is a command that supports the new uverbs command header format
suggested in this patch) w/o bumping ABI version and with maintaining backward
and formward compatibility to new and old libibverbs versions.
In the uverbs command we are passing both uverbs arguments and the provider arguments.
We split the ib_uverbs_cmd_hdr.in_words to ib_uverbs_cmd_hdr.in_words which will now carry only
uverbs input argument struct size and ib_uverbs_cmd_hdr.provider_in_words that will carry
the provider input argument size. Same goes for the response (the uverbs CMD output argument).
For example take the create_cq call and the mlx4_ib provider:
The uverbs layer gets libibverb's struct ibv_create_cq (named struct ib_uverbs_create_cq
in the kernel), mlx4_ib gets libmlx4's struct mlx4_create_cq (which includes struct
ibv_create_cq and is named struct mlx4_ib_create_cq in the kernel) and
in_words = sizeof(mlx4_create_cq)/4 .
Thus ib_uverbs_cmd_hdr.in_words carry both uverbs plus mlx4_ib input argument sizes,
where uverbs assumes it knows the size of its input argument - struct ibv_create_cq.
Now, if we wish to add a variable to struct ibv_create_cq, we can add a comp_mask field
to the struct which is basically bit field indicating which fields exists in the struct
(as done for the libibverbs API extension), but we need a way to tell what is the total
size of the struct and not assume the struct size is predefined (since we may get different
struct sizes from different user libibverbs versions). So we know at which point the
provider input argument (struct mlx4_create_cq) begins. Same goes for extending the
provider struct mlx4_create_cq. Thus we split the ib_uverbs_cmd_hdr.in_words to
ib_uverbs_cmd_hdr.in_words which will now carry only uverbs input argument struct size and
ib_uverbs_cmd_hdr.provider_in_words that will carry the provider (mlx4_ib) input argument size.
Signed-off-by: Igor Ivanov <Igor.Ivanov@itseez.com>
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
The existing user/kernel uverbs API has IB_USER_VERBS_CMD_ALLOC/DEALLOC_MW.
Implement these calls, along with destroying user memory windows during
process cleanup.
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
