Add netdev_rx_queue_restart(), which resets an rx queue using the
queue API recently merged[1].
The queue API was merged to enable the core net stack to reset individual
rx queues to actuate changes in the rx queue's configuration. In later
patches in this series, we will use netdev_rx_queue_restart() to reset
rx queues after binding or unbinding dmabuf configuration, which will
cause reallocation of the page_pool to repopulate its memory using the
new configuration.
[1] https://lore.kernel.org/netdev/20240430231420.699177-1-shailend@google.com/…
Signed-off-by: David Wei <dw(a)davidwei.uk>
Signed-off-by: Mina Almasry <almasrymina(a)google.com>
Reviewed-by: Pavel Begunkov <asml.silence(a)gmail.com>
Reviewed-by: Jakub Kicinski <kuba(a)kernel.org>
---
v18:
- Add more color to commit message (Xuan Zhuo).
v17:
- Use ASSERT_RTNL() (Jakub).
v13:
- Add reviewed-by from Pavel (thanks!)
- Fixed comment (Pavel)
v11:
- Fix not checking dev->queue_mgmt_ops (Pavel).
- Fix ndo_queue_mem_free call that passed the wrong pointer (David).
v9: https://lore.kernel.org/all/20240502045410.3524155-4-dw@davidwei.uk/
(submitted by David).
- fixed SPDX license identifier (Simon).
- Rebased on top of merged queue API definition, and changed
implementation to match that.
- Replace rtnl_lock() with rtnl_is_locked() to make it useable from my
netlink code where rtnl is already locked.
---
include/net/netdev_rx_queue.h | 3 ++
net/core/Makefile | 1 +
net/core/netdev_rx_queue.c | 74 +++++++++++++++++++++++++++++++++++
3 files changed, 78 insertions(+)
create mode 100644 net/core/netdev_rx_queue.c
diff --git a/include/net/netdev_rx_queue.h b/include/net/netdev_rx_queue.h
index aa1716fb0e53..e78ca52d67fb 100644
--- a/include/net/netdev_rx_queue.h
+++ b/include/net/netdev_rx_queue.h
@@ -54,4 +54,7 @@ get_netdev_rx_queue_index(struct netdev_rx_queue *queue)
return index;
}
#endif
+
+int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq);
+
#endif
diff --git a/net/core/Makefile b/net/core/Makefile
index 62be9aef2528..f82232b358a2 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_NETDEV_ADDR_LIST_TEST) += dev_addr_lists_test.o
obj-y += net-sysfs.o
obj-y += hotdata.o
+obj-y += netdev_rx_queue.o
obj-$(CONFIG_PAGE_POOL) += page_pool.o page_pool_user.o
obj-$(CONFIG_PROC_FS) += net-procfs.o
obj-$(CONFIG_NET_PKTGEN) += pktgen.o
diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
new file mode 100644
index 000000000000..da11720a5983
--- /dev/null
+++ b/net/core/netdev_rx_queue.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/netdevice.h>
+#include <net/netdev_queues.h>
+#include <net/netdev_rx_queue.h>
+
+int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
+{
+ void *new_mem, *old_mem;
+ int err;
+
+ if (!dev->queue_mgmt_ops || !dev->queue_mgmt_ops->ndo_queue_stop ||
+ !dev->queue_mgmt_ops->ndo_queue_mem_free ||
+ !dev->queue_mgmt_ops->ndo_queue_mem_alloc ||
+ !dev->queue_mgmt_ops->ndo_queue_start)
+ return -EOPNOTSUPP;
+
+ ASSERT_RTNL();
+
+ new_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
+ if (!new_mem)
+ return -ENOMEM;
+
+ old_mem = kvzalloc(dev->queue_mgmt_ops->ndo_queue_mem_size, GFP_KERNEL);
+ if (!old_mem) {
+ err = -ENOMEM;
+ goto err_free_new_mem;
+ }
+
+ err = dev->queue_mgmt_ops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx);
+ if (err)
+ goto err_free_old_mem;
+
+ err = dev->queue_mgmt_ops->ndo_queue_stop(dev, old_mem, rxq_idx);
+ if (err)
+ goto err_free_new_queue_mem;
+
+ err = dev->queue_mgmt_ops->ndo_queue_start(dev, new_mem, rxq_idx);
+ if (err)
+ goto err_start_queue;
+
+ dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
+
+ kvfree(old_mem);
+ kvfree(new_mem);
+
+ return 0;
+
+err_start_queue:
+ /* Restarting the queue with old_mem should be successful as we haven't
+ * changed any of the queue configuration, and there is not much we can
+ * do to recover from a failure here.
+ *
+ * WARN if we fail to recover the old rx queue, and at least free
+ * old_mem so we don't also leak that.
+ */
+ if (dev->queue_mgmt_ops->ndo_queue_start(dev, old_mem, rxq_idx)) {
+ WARN(1,
+ "Failed to restart old queue in error path. RX queue %d may be unhealthy.",
+ rxq_idx);
+ dev->queue_mgmt_ops->ndo_queue_mem_free(dev, old_mem);
+ }
+
+err_free_new_queue_mem:
+ dev->queue_mgmt_ops->ndo_queue_mem_free(dev, new_mem);
+
+err_free_old_mem:
+ kvfree(old_mem);
+
+err_free_new_mem:
+ kvfree(new_mem);
+
+ return err;
+}
--
2.46.0.76.ge559c4bf1a-goog
GCC 13.2.0 reported warning about (void *) being used as a param where (char *)
is expected:
In file included from msg_oob.c:14:
msg_oob.c: In function ‘__recvpair’:
../../kselftest_harness.h:106:40: warning: format ‘%s’ expects argument of type ‘char *’, \
but argument 6 has type ‘const void *’ [-Wformat=]
106 | fprintf(TH_LOG_STREAM, "# %s:%d:%s:" fmt "\n", \
| ^~~~~~~~~~~~~
../../kselftest_harness.h:101:17: note: in expansion of macro ‘__TH_LOG’
101 | __TH_LOG(fmt, ##__VA_ARGS__); \
| ^~~~~~~~
msg_oob.c:235:17: note: in expansion of macro ‘TH_LOG’
235 | TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf);
| ^~~~~~
../../kselftest_harness.h:106:40: warning: format ‘%s’ expects argument of type ‘char *’, \
but argument 6 has type ‘const void *’ [-Wformat=]
106 | fprintf(TH_LOG_STREAM, "# %s:%d:%s:" fmt "\n", \
| ^~~~~~~~~~~~~
../../kselftest_harness.h:101:17: note: in expansion of macro ‘__TH_LOG’
101 | __TH_LOG(fmt, ##__VA_ARGS__); \
| ^~~~~~~~
msg_oob.c:259:25: note: in expansion of macro ‘TH_LOG’
259 | TH_LOG("Expected:%s", expected_errno ? strerror(expected_errno) : expected_buf);
| ^~~~~~
As Simon suggested, all calls to __recvpair() have char * as expected_buf param, so
it is safe to change param type from (const void *) to (const char *), which silences
the warning.
Fixes: d098d77232c37 ("selftest: af_unix: Add msg_oob.c.")
Reported-by: Mirsad Todorovac <mtodorovac69(a)gmail.com>
Cc: "David S. Miller" <davem(a)davemloft.net>
Cc: Eric Dumazet <edumazet(a)google.com>
Cc: Jakub Kicinski <kuba(a)kernel.org>
Cc: Paolo Abeni <pabeni(a)redhat.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Kuniyuki Iwashima <kuniyu(a)amazon.com>
Cc: netdev(a)vger.kernel.org
Cc: linux-kselftest(a)vger.kernel.org
Suggested-by: Simon Horman <horms(a)kernel.org>
Signed-off-by: Mirsad Todorovac <mtodorovac69(a)gmail.com>
---
v1 -> v2:
fixed a typo.
change funct param type rather than making two casts, as Simon suggested.
changed Subject: line to reflect the modification.
minor formatting changes.
v1:
initial version to fix the compiler warning.
tools/testing/selftests/net/af_unix/msg_oob.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/net/af_unix/msg_oob.c b/tools/testing/selftests/net/af_unix/msg_oob.c
index 16d0c172eaeb..535eb2c3d7d1 100644
--- a/tools/testing/selftests/net/af_unix/msg_oob.c
+++ b/tools/testing/selftests/net/af_unix/msg_oob.c
@@ -209,7 +209,7 @@ static void __sendpair(struct __test_metadata *_metadata,
static void __recvpair(struct __test_metadata *_metadata,
FIXTURE_DATA(msg_oob) *self,
- const void *expected_buf, int expected_len,
+ const char *expected_buf, int expected_len,
int buf_len, int flags)
{
int i, ret[2], recv_errno[2], expected_errno = 0;
--
2.43.0
The BPF tracing infrastructure has undergone significant evolution,
leading to the introduction of more robust and efficient APIs.
However, some of the existing tests in the samples/bpf directory have
not kept pace with these developments. These outdated tests not only
create confusion among users but also increase maintenance overhead.
For starter, this patchset focuses on cleaning up outdated 'tracing'
related tests within the BPF testing framework. The goal is to
modernize and streamline selftests by removing obsolete tests and
migrating necessaries to more appropriate locations.
Daniel T. Lee (3):
selftests/bpf: migrate tracepoint overhead test to prog_tests
selftests/bpf: add rename tracepoint bench test
samples/bpf: remove obsolete tracing related tests
samples/bpf/Makefile | 12 -
samples/bpf/test_overhead_kprobe.bpf.c | 41 ----
samples/bpf/test_overhead_raw_tp.bpf.c | 17 --
samples/bpf/test_overhead_tp.bpf.c | 23 --
samples/bpf/test_overhead_user.c | 225 ------------------
samples/bpf/test_override_return.sh | 16 --
samples/bpf/test_probe_write_user.bpf.c | 52 ----
samples/bpf/test_probe_write_user_user.c | 108 ---------
samples/bpf/tracex7.bpf.c | 15 --
samples/bpf/tracex7_user.c | 56 -----
tools/testing/selftests/bpf/bench.c | 2 +
.../selftests/bpf/benchs/bench_rename.c | 16 ++
.../selftests/bpf/benchs/run_bench_rename.sh | 2 +-
.../selftests/bpf/prog_tests/test_overhead.c | 14 +-
.../selftests/bpf/progs/test_overhead.c | 11 +-
15 files changed, 39 insertions(+), 571 deletions(-)
delete mode 100644 samples/bpf/test_overhead_kprobe.bpf.c
delete mode 100644 samples/bpf/test_overhead_raw_tp.bpf.c
delete mode 100644 samples/bpf/test_overhead_tp.bpf.c
delete mode 100644 samples/bpf/test_overhead_user.c
delete mode 100755 samples/bpf/test_override_return.sh
delete mode 100644 samples/bpf/test_probe_write_user.bpf.c
delete mode 100644 samples/bpf/test_probe_write_user_user.c
delete mode 100644 samples/bpf/tracex7.bpf.c
delete mode 100644 samples/bpf/tracex7_user.c
--
2.43.0
This patchset introduces SEV-SNP test to the kernel selftest framework.
It also adds negative testing of SEV, ES and SNP VM types.
Patch 1 - Extend the sev smoke tests to use the SNP specific ioctl
calls and sets up memory to boot a SNP guest VM
Patch 2 - Cleanup patch that decouples the ioctl calls from the sev
selftest library with its test assert and status counterparts. No
functional change introduced
Patch 3 - Introduce ioctl test for SEV, ES
Patch 4 - Introduce positive and negative ioctl test for SEV-SNP
Patch 5 - Adds the X86_FEATURE_SEV_SNP vm type test for KVM_SEV_INIT2
Any feedback/review on the approach and design is highly appreciated!
Pratik R. Sampat (5):
selftests: KVM: Add a basic SNP smoke test
selftests: KVM: Decouple SEV ioctls from asserts
selftests: KVM: SEV IOCTL test
selftests: KVM: SNP IOCTL test
selftests: KVM: SEV-SNP test for KVM_SEV_INIT2
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/include/x86_64/sev.h | 39 ++-
tools/testing/selftests/kvm/lib/kvm_util.c | 7 +-
.../selftests/kvm/lib/x86_64/processor.c | 6 +-
tools/testing/selftests/kvm/lib/x86_64/sev.c | 181 +++++++++++---
.../selftests/kvm/x86_64/sev_init2_tests.c | 13 +
.../selftests/kvm/x86_64/sev_smoke_test.c | 223 +++++++++++++++++-
7 files changed, 418 insertions(+), 52 deletions(-)
--
2.34.1
v18: https://patchwork.kernel.org/project/netdevbpf/list/?series=874848&state=*
====
v17 got minor feedback: (a) to beef up the description on patch 1 and (b)
to remove the leading underscores in the header definition.
I applied (a). (b) seems to be against current conventions so I did not
apply before further discussion.
Full devmem TCP changes including the full GVE driver implementation is
here:
https://github.com/mina/linux/commits/tcpdevmem-v17/
v17: https://patchwork.kernel.org/project/netdevbpf/list/?series=869900&state=*
====
v16 also got a very thorough review and some testing (thanks again!).
Thes version addresses all the concerns reported on v15, in terms of
feedback and issues reported.
Major changes:
- Use ASSERT_RTNL.
- Moved around some of the page_pool helpers definitions so I can hide
some netmem helpers in private files as Jakub suggested.
- Don't make every net_iov hold a ref on the binding as Jakub suggested.
- Fix issue reported by Taehee where we access queues after they have
been freed.
Full devmem TCP changes including the full GVE driver implementation is
here:
https://github.com/mina/linux/commits/tcpdevmem-v17/
v16: https://patchwork.kernel.org/project/netdevbpf/list/?series=866353&state=*
====
v15 got a thorough review and some testing, and this version addresses almost
all the feedback. Some more minor comments where the authors said it
could be done later, I left out.
Major changes:
- Addition of dma-buf introspection to page-pool-get and queue-get.
- Fixes to selftests suggested by Taehee.
- Fixes to documentation suggested by Donald.
- A couple of suggestions and fixes to TCP patches by Eric and David.
- Fixes to number assignements suggested by Arnd.
- Use rtnl_lock()ing to guard against queue reconfiguration while the
page_pool initialization is happening. (Jakub).
- Fixes to a few warnings reproduced by Taehee.
- Fixes to dma-buf binding suggested by Taehee and Jakub.
- Fixes to netlink UAPI suggested by Jakub
- Applied a number of Reviewed-bys and Acked-bys (including ones I lost
from v13+).
Full devmem TCP changes including the full GVE driver implementation is
here:
https://github.com/mina/linux/commits/tcpdevmem-v16/
One caveat: Taehee reproduced a KASAN warning and reported it here:
https://lore.kernel.org/netdev/CAMArcTUdCxOBYGF3vpbq=eBvqZfnc44KBaQTN7H-wqd…
I estimate the issue to be minor and easily fixable:
https://lore.kernel.org/netdev/CAHS8izNgaqC--GGE2xd85QB=utUnOHmioCsDd1TNxJW…
I hope to be able to follow up with a fix to net tree as net-next closes
imminently, but if this iteration doesn't make it in, I will repost with
a fix squashed after net-next reopens, no problem.
v15: https://patchwork.kernel.org/project/netdevbpf/list/?series=865481&state=*
====
No material changes in this version, only a fix to linking against
libynl.a from the last version. Per Jakub's instructions I've pulled one
of his patches into this series, and now use the new libynl.a correctly,
I hope.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v15/
v14: https://patchwork.kernel.org/project/netdevbpf/list/?series=865135&archive=…
====
No material changes in this version. Only rebase and re-verification on
top of net-next. v13, I think, raced with commit ebad6d0334793
("net/ipv4: Use nested-BH locking for ipv4_tcp_sk.") being merged to
net-next that caused a patchwork failure to apply. This series should
apply cleanly on commit c4532232fa2a4 ("selftests: net: remove unneeded
IP_GRE config").
I did not wait the customary 24hr as Jakub said it's OK to repost as soon
as I build test the rebased version:
https://lore.kernel.org/netdev/20240625075926.146d769d@kernel.org/
v13: https://patchwork.kernel.org/project/netdevbpf/list/?series=861406&archive=…
====
Major changes:
--------------
This iteration addresses Pavel's review comments, applies his
reviewed-by's, and seeks to fix the patchwork build error (sorry!).
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v13/
v12: https://patchwork.kernel.org/project/netdevbpf/list/?series=859747&state=*
====
Major changes:
--------------
This iteration only addresses one minor comment from Pavel with regards
to the trace printing of netmem, and the patchwork build error
introduced in v11 because I missed doing an allmodconfig build, sorry.
Other than that v11, AFAICT, received no feedback. There is one
discussion about how the specifics of plugging io uring memory through
the page pool, but not relevant to content in this particular patchset,
AFAICT.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v12/
v11: https://patchwork.kernel.org/project/netdevbpf/list/?series=857457&state=*
====
Major Changes:
--------------
v11 addresses feedback received in v10. The major change is the removal
of the memory provider ops as requested by Christoph. We still
accomplish the same thing, but utilizing direct function calls with if
statements rather than generic ops.
Additionally address sparse warnings, bugs and review comments from
folks that reviewed.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v11/
Detailed changelog:
-------------------
- Fixes in netdev_rx_queue_restart() from Pavel & David.
- Remove commit e650e8c3a36f5 ("net: page_pool: create hooks for
custom page providers") from the series to address Christoph's
feedback and rebased other patches on the series on this change.
- Fixed build errors with CONFIG_DMA_SHARED_BUFFER &&
!CONFIG_GENERIC_ALLOCATOR build.
- Fixed sparse warnings pointed out by Paolo.
- Drop unnecessary gro_pull_from_frag0 checks.
- Added Bagas reviewed-by to docs.
Cc: Bagas Sanjaya <bagasdotme(a)gmail.com>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Christoph Hellwig <hch(a)infradead.org>
Cc: Nikolay Aleksandrov <razor(a)blackwall.org>
Cc: Taehee Yoo <ap420073(a)gmail.com>
Cc: Donald Hunter <donald.hunter(a)gmail.com>
v10: https://patchwork.kernel.org/project/netdevbpf/list/?series=852422&state=*
====
Major Changes:
--------------
v9 was sent right before the merge window closed (sorry!). v10 is almost
a re-send of the series now that the merge window re-opened. Only
rebased to latest net-next and addressed some minor iterative comments
received on v9.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v10/
Detailed changelog:
-------------------
- Fixed tokens leaking in DONTNEED setsockopt (Nikolay).
- Moved net_iov_dma_addr() to devmem.c and made it a devmem specific
helpers (David).
- Rename hook alloc_pages to alloc_netmems as alloc_pages is now
preprocessor macro defined and causes a build error.
v9:
===
Major Changes:
--------------
GVE queue API has been merged. Submitting this version as non-RFC after
rebasing on top of the merged API, and dropped the out of tree queue API
I was carrying on github. Addressed the little feedback v8 has received.
Detailed changelog:
------------------
- Added new patch from David Wei to this series for
netdev_rx_queue_restart()
- Fixed sparse error.
- Removed CONFIG_ checks in netmem_is_net_iov()
- Flipped skb->readable to skb->unreadable
- Minor fixes to selftests & docs.
RFC v8:
=======
Major Changes:
--------------
- Fixed build error generated by patch-by-patch build.
- Applied docs suggestions from Randy.
RFC v7:
=======
Major Changes:
--------------
This revision largely rebases on top of net-next and addresses the feedback
RFCv6 received from folks, namely Jakub, Yunsheng, Arnd, David, & Pavel.
The series remains in RFC because the queue-API ndos defined in this
series are not yet implemented. I have a GVE implementation I carry out
of tree for my testing. A upstreamable GVE implementation is in the
works. Aside from that, in my estimation all the patches are ready for
review/merge. Please do take a look.
As usual the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v7/
Detailed changelog:
- Use admin-perm in netlink API.
- Addressed feedback from Jakub with regards to netlink API
implementation.
- Renamed devmem.c functions to something more appropriate for that
file.
- Improve the performance seen through the page_pool benchmark.
- Fix the value definition of all the SO_DEVMEM_* uapi.
- Various fixes to documentation.
Perf - page-pool benchmark:
---------------------------
Improved performance of bench_page_pool_simple.ko tests compared to v6:
https://pastebin.com/raw/v5dYRg8L
net-next base: 8 cycle fast path.
RFC v6: 10 cycle fast path.
RFC v7: 9 cycle fast path.
RFC v7 with CONFIG_DMA_SHARED_BUFFER disabled: 8 cycle fast path,
same as baseline.
Perf - Devmem TCP benchmark:
---------------------
Perf is about the same regardless of the changes in v7, namely the
removal of the static_branch_unlikely to improve the page_pool benchmark
performance:
189/200gbps bi-directional throughput with RX devmem TCP and regular TCP
TX i.e. ~95% line rate.
RFC v6:
=======
Major Changes:
--------------
This revision largely rebases on top of net-next and addresses the little
feedback RFCv5 received.
The series remains in RFC because the queue-API ndos defined in this
series are not yet implemented. I have a GVE implementation I carry out
of tree for my testing. A upstreamable GVE implementation is in the
works. Aside from that, in my estimation all the patches are ready for
review/merge. Please do take a look.
As usual the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v6/
This version also comes with some performance data recorded in the cover
letter (see below changelog).
Detailed changelog:
- Rebased on top of the merged netmem_ref changes.
- Converted skb->dmabuf to skb->readable (Pavel). Pavel's original
suggestion was to remove the skb->dmabuf flag entirely, but when I
looked into it closely, I found the issue that if we remove the flag
we have to dereference the shinfo(skb) pointer to obtain the first
frag to tell whether an skb is readable or not. This can cause a
performance regression if it dirties the cache line when the
shinfo(skb) was not really needed. Instead, I converted the skb->dmabuf
flag into a generic skb->readable flag which can be re-used by io_uring
0-copy RX.
- Squashed a few locking optimizations from Eric Dumazet in the RX path
and the DEVMEM_DONTNEED setsockopt.
- Expanded the tests a bit. Added validation for invalid scenarios and
added some more coverage.
Perf - page-pool benchmark:
---------------------------
bench_page_pool_simple.ko tests with and without these changes:
https://pastebin.com/raw/ncHDwAbn
AFAIK the number that really matters in the perf tests is the
'tasklet_page_pool01_fast_path Per elem'. This one measures at about 8
cycles without the changes but there is some 1 cycle noise in some
results.
With the patches this regresses to 9 cycles with the changes but there
is 1 cycle noise occasionally running this test repeatedly.
Lastly I tried disable the static_branch_unlikely() in
netmem_is_net_iov() check. To my surprise disabling the
static_branch_unlikely() check reduces the fast path back to 8 cycles,
but the 1 cycle noise remains.
Perf - Devmem TCP benchmark:
---------------------
189/200gbps bi-directional throughput with RX devmem TCP and regular TCP
TX i.e. ~95% line rate.
Major changes in RFC v5:
========================
1. Rebased on top of 'Abstract page from net stack' series and used the
new netmem type to refer to LSB set pointers instead of re-using
struct page.
2. Downgraded this series back to RFC and called it RFC v5. This is
because this series is now dependent on 'Abstract page from net
stack'[1] and the queue API. Both are removed from the series to
reduce the patch # and those bits are fairly independent or
pre-requisite work.
3. Reworked the page_pool devmem support to use netmem and for some
more unified handling.
4. Reworked the reference counting of net_iov (renamed from
page_pool_iov) to use pp_ref_count for refcounting.
The full changes including the dependent series and GVE page pool
support is here:
https://github.com/mina/linux/commits/tcpdevmem-rfcv5/
[1] https://patchwork.kernel.org/project/netdevbpf/list/?series=810774
Major changes in v1:
====================
1. Implemented MVP queue API ndos to remove the userspace-visible
driver reset.
2. Fixed issues in the napi_pp_put_page() devmem frag unref path.
3. Removed RFC tag.
Many smaller addressed comments across all the patches (patches have
individual change log).
Full tree including the rest of the GVE driver changes:
https://github.com/mina/linux/commits/tcpdevmem-v1
Changes in RFC v3:
==================
1. Pulled in the memory-provider dependency from Jakub's RFC[1] to make the
series reviewable and mergeable.
2. Implemented multi-rx-queue binding which was a todo in v2.
3. Fix to cmsg handling.
The sticking point in RFC v2[2] was the device reset required to refill
the device rx-queues after the dmabuf bind/unbind. The solution
suggested as I understand is a subset of the per-queue management ops
Jakub suggested or similar:
https://lore.kernel.org/netdev/20230815171638.4c057dcd@kernel.org/
This is not addressed in this revision, because:
1. This point was discussed at netconf & netdev and there is openness to
using the current approach of requiring a device reset.
2. Implementing individual queue resetting seems to be difficult for my
test bed with GVE. My prototype to test this ran into issues with the
rx-queues not coming back up properly if reset individually. At the
moment I'm unsure if it's a mistake in the POC or a genuine issue in
the virtualization stack behind GVE, which currently doesn't test
individual rx-queue restart.
3. Our usecases are not bothered by requiring a device reset to refill
the buffer queues, and we'd like to support NICs that run into this
limitation with resetting individual queues.
My thought is that drivers that have trouble with per-queue configs can
use the support in this series, while drivers that support new netdev
ops to reset individual queues can automatically reset the queue as
part of the dma-buf bind/unbind.
The same approach with device resets is presented again for consideration
with other sticking points addressed.
This proposal includes the rx devmem path only proposed for merge. For a
snapshot of my entire tree which includes the GVE POC page pool support &
device memory support:
https://github.com/torvalds/linux/compare/master...mina:linux:tcpdevmem-v3
[1] https://lore.kernel.org/netdev/f8270765-a27b-6ccf-33ea-cda097168d79@redhat.…
[2] https://lore.kernel.org/netdev/CAHS8izOVJGJH5WF68OsRWFKJid1_huzzUK+hpKbLcL4…
Changes in RFC v2:
==================
The sticking point in RFC v1[1] was the dma-buf pages approach we used to
deliver the device memory to the TCP stack. RFC v2 is a proof-of-concept
that attempts to resolve this by implementing scatterlist support in the
networking stack, such that we can import the dma-buf scatterlist
directly. This is the approach proposed at a high level here[2].
Detailed changes:
1. Replaced dma-buf pages approach with importing scatterlist into the
page pool.
2. Replace the dma-buf pages centric API with a netlink API.
3. Removed the TX path implementation - there is no issue with
implementing the TX path with scatterlist approach, but leaving
out the TX path makes it easier to review.
4. Functionality is tested with this proposal, but I have not conducted
perf testing yet. I'm not sure there are regressions, but I removed
perf claims from the cover letter until they can be re-confirmed.
5. Added Signed-off-by: contributors to the implementation.
6. Fixed some bugs with the RX path since RFC v1.
Any feedback welcome, but specifically the biggest pending questions
needing feedback IMO are:
1. Feedback on the scatterlist-based approach in general.
2. Netlink API (Patch 1 & 2).
3. Approach to handle all the drivers that expect to receive pages from
the page pool (Patch 6).
[1] https://lore.kernel.org/netdev/dfe4bae7-13a0-3c5d-d671-f61b375cb0b4@gmail.c…
[2] https://lore.kernel.org/netdev/CAHS8izPm6XRS54LdCDZVd0C75tA1zHSu6jLVO8nzTLX…
==================
* TL;DR:
Device memory TCP (devmem TCP) is a proposal for transferring data to and/or
from device memory efficiently, without bouncing the data to a host memory
buffer.
* Problem:
A large amount of data transfers have device memory as the source and/or
destination. Accelerators drastically increased the volume of such transfers.
Some examples include:
- ML accelerators transferring large amounts of training data from storage into
GPU/TPU memory. In some cases ML training setup time can be as long as 50% of
TPU compute time, improving data transfer throughput & efficiency can help
improving GPU/TPU utilization.
- Distributed training, where ML accelerators, such as GPUs on different hosts,
exchange data among them.
- Distributed raw block storage applications transfer large amounts of data with
remote SSDs, much of this data does not require host processing.
Today, the majority of the Device-to-Device data transfers the network are
implemented as the following low level operations: Device-to-Host copy,
Host-to-Host network transfer, and Host-to-Device copy.
The implementation is suboptimal, especially for bulk data transfers, and can
put significant strains on system resources, such as host memory bandwidth,
PCIe bandwidth, etc. One important reason behind the current state is the
kernel’s lack of semantics to express device to network transfers.
* Proposal:
In this patch series we attempt to optimize this use case by implementing
socket APIs that enable the user to:
1. send device memory across the network directly, and
2. receive incoming network packets directly into device memory.
Packet _payloads_ go directly from the NIC to device memory for receive and from
device memory to NIC for transmit.
Packet _headers_ go to/from host memory and are processed by the TCP/IP stack
normally. The NIC _must_ support header split to achieve this.
Advantages:
- Alleviate host memory bandwidth pressure, compared to existing
network-transfer + device-copy semantics.
- Alleviate PCIe BW pressure, by limiting data transfer to the lowest level
of the PCIe tree, compared to traditional path which sends data through the
root complex.
* Patch overview:
** Part 1: netlink API
Gives user ability to bind dma-buf to an RX queue.
** Part 2: scatterlist support
Currently the standard for device memory sharing is DMABUF, which doesn't
generate struct pages. On the other hand, networking stack (skbs, drivers, and
page pool) operate on pages. We have 2 options:
1. Generate struct pages for dmabuf device memory, or,
2. Modify the networking stack to process scatterlist.
Approach #1 was attempted in RFC v1. RFC v2 implements approach #2.
** part 3: page pool support
We piggy back on page pool memory providers proposal:
https://github.com/kuba-moo/linux/tree/pp-providers
It allows the page pool to define a memory provider that provides the
page allocation and freeing. It helps abstract most of the device memory
TCP changes from the driver.
** part 4: support for unreadable skb frags
Page pool iovs are not accessible by the host; we implement changes
throughput the networking stack to correctly handle skbs with unreadable
frags.
** Part 5: recvmsg() APIs
We define user APIs for the user to send and receive device memory.
Not included with this series is the GVE devmem TCP support, just to
simplify the review. Code available here if desired:
https://github.com/mina/linux/tree/tcpdevmem
This series is built on top of net-next with Jakub's pp-providers changes
cherry-picked.
* NIC dependencies:
1. (strict) Devmem TCP require the NIC to support header split, i.e. the
capability to split incoming packets into a header + payload and to put
each into a separate buffer. Devmem TCP works by using device memory
for the packet payload, and host memory for the packet headers.
2. (optional) Devmem TCP works better with flow steering support & RSS support,
i.e. the NIC's ability to steer flows into certain rx queues. This allows the
sysadmin to enable devmem TCP on a subset of the rx queues, and steer
devmem TCP traffic onto these queues and non devmem TCP elsewhere.
The NIC I have access to with these properties is the GVE with DQO support
running in Google Cloud, but any NIC that supports these features would suffice.
I may be able to help reviewers bring up devmem TCP on their NICs.
* Testing:
The series includes a udmabuf kselftest that show a simple use case of
devmem TCP and validates the entire data path end to end without
a dependency on a specific dmabuf provider.
** Test Setup
Kernel: net-next with this series and memory provider API cherry-picked
locally.
Hardware: Google Cloud A3 VMs.
NIC: GVE with header split & RSS & flow steering support.
Cc: Pavel Begunkov <asml.silence(a)gmail.com>
Cc: David Wei <dw(a)davidwei.uk>
Cc: Jason Gunthorpe <jgg(a)ziepe.ca>
Cc: Yunsheng Lin <linyunsheng(a)huawei.com>
Cc: Shailend Chand <shailend(a)google.com>
Cc: Harshitha Ramamurthy <hramamurthy(a)google.com>
Cc: Shakeel Butt <shakeel.butt(a)linux.dev>
Cc: Jeroen de Borst <jeroendb(a)google.com>
Cc: Praveen Kaligineedi <pkaligineedi(a)google.com>
Mina Almasry (14):
netdev: add netdev_rx_queue_restart()
net: netdev netlink api to bind dma-buf to a net device
netdev: support binding dma-buf to netdevice
netdev: netdevice devmem allocator
page_pool: move dmaddr helpers to .c file
page_pool: devmem support
memory-provider: dmabuf devmem memory provider
net: support non paged skb frags
net: add support for skbs with unreadable frags
tcp: RX path for devmem TCP
net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags
net: add devmem TCP documentation
selftests: add ncdevmem, netcat for devmem TCP
netdev: add dmabuf introspection
Documentation/netlink/specs/netdev.yaml | 61 +++
Documentation/networking/devmem.rst | 269 ++++++++++++
Documentation/networking/index.rst | 1 +
arch/alpha/include/uapi/asm/socket.h | 6 +
arch/mips/include/uapi/asm/socket.h | 6 +
arch/parisc/include/uapi/asm/socket.h | 6 +
arch/sparc/include/uapi/asm/socket.h | 6 +
include/linux/skbuff.h | 61 ++-
include/linux/skbuff_ref.h | 9 +-
include/linux/socket.h | 1 +
include/net/devmem.h | 128 ++++++
include/net/mp_dmabuf_devmem.h | 44 ++
include/net/netdev_rx_queue.h | 5 +
include/net/netmem.h | 164 +++++++-
include/net/page_pool/helpers.h | 42 +-
include/net/page_pool/types.h | 8 +
include/net/sock.h | 2 +
include/net/tcp.h | 5 +-
include/trace/events/page_pool.h | 12 +-
include/uapi/asm-generic/socket.h | 6 +
include/uapi/linux/netdev.h | 13 +
include/uapi/linux/uio.h | 17 +
net/core/Makefile | 3 +-
net/core/datagram.c | 6 +
net/core/dev.c | 7 +-
net/core/devmem.c | 378 +++++++++++++++++
net/core/gro.c | 3 +-
net/core/netdev-genl-gen.c | 23 +
net/core/netdev-genl-gen.h | 6 +
net/core/netdev-genl.c | 111 +++++
net/core/netdev_rx_queue.c | 74 ++++
net/core/netmem_priv.h | 36 ++
net/core/page_pool.c | 147 +++++--
net/core/page_pool_priv.h | 3 +
net/core/page_pool_user.c | 4 +
net/core/skbuff.c | 77 +++-
net/core/sock.c | 68 +++
net/ipv4/esp4.c | 3 +-
net/ipv4/tcp.c | 261 +++++++++++-
net/ipv4/tcp_input.c | 13 +-
net/ipv4/tcp_ipv4.c | 16 +
net/ipv4/tcp_minisocks.c | 2 +
net/ipv4/tcp_output.c | 5 +-
net/ipv6/esp6.c | 3 +-
net/packet/af_packet.c | 4 +-
tools/include/uapi/linux/netdev.h | 13 +
tools/testing/selftests/net/.gitignore | 1 +
tools/testing/selftests/net/Makefile | 9 +
tools/testing/selftests/net/ncdevmem.c | 536 ++++++++++++++++++++++++
49 files changed, 2563 insertions(+), 121 deletions(-)
create mode 100644 Documentation/networking/devmem.rst
create mode 100644 include/net/devmem.h
create mode 100644 include/net/mp_dmabuf_devmem.h
create mode 100644 net/core/devmem.c
create mode 100644 net/core/netdev_rx_queue.c
create mode 100644 net/core/netmem_priv.h
create mode 100644 tools/testing/selftests/net/ncdevmem.c
--
2.46.0.rc2.264.g509ed76dc8-goog
This patch series adds a selftest suite to validate the s390x
architecture specific ucontrol KVM interface.
When creating a VM on s390x it is possible to create it as userspace
controlled VM or in short ucontrol VM.
These VMs delegates the management of the VM to userspace instead
of handling most events within the kernel. Consequently the userspace
has to manage interrupts, memory allocation etc.
Before this patch set this functionality lacks any public test cases.
It is desirable to add test cases for this interface to be able to
reduce the risk of breaking changes in the future.
In order to provision a ucontrol VM the kernel needs to be compiled with
the CONFIG_KVM_S390_UCONTROL enabled. The users with sys_admin capability
can then create a new ucontrol VM providing the KVM_VM_S390_UCONTROL
parameter to the KVM_CREATE_VM ioctl.
The kernels existing selftest helper functions can only be partially be
reused for these tests.
The test cases cover existing special handling of ucontrol VMs within the
implementation and basic VM creation and handling cases:
* Reject setting HPAGE when VM is ucontrol
* Assert KVM_GET_DIRTY_LOG is rejected
* Assert KVM_S390_VM_MEM_LIMIT_SIZE is rejected
* Assert state of initial SIE flags setup by the kernel
* Run simple program in VM with and without DAT
* Assert KVM_EXIT_S390_UCONTROL exit on not mapped memory access
* Assert functionality of storage keys in ucontrol VM
* Assert that memory region operations are rejected for ucontrol VMs
Running the test cases requires sys_admin capabilities to start the
ucontrol VM.
This can be achieved by running as root or with a command like:
sudo setpriv --reuid nobody --inh-caps -all,+sys_admin \
--ambient-caps -all,+sys_admin --bounding-set -all,+sys_admin \
./ucontrol_test
The patch set does also contain some code cleanup / consolidation of
architecture specific defines that are now used in multiple test cases.
---
v5:
- PATCH 7: Simplify segment and page table generation
- PATCH 8: Remove irrelevant code in skey test
Add some comments to skey test
v4:
- PATCH 5: Remove not yet used include for debug print functions
- PATCH 6: Add include for debug print functions (removed from patch 5)
Remove no longer needed code since stopped but is reset
before starting since v3 (thanks Janosch)
Adjust test output to use leading zeros instead of spaces in sieic
- PATCH 7: Rename constant to PGM_SEGMENT_TRANSLATION (thanks Janosch)
Put comments on their own lines
v3:
- Remove stopped bit before starting the VM (no initial stop in multiple
test cases) (thanks Janosch)
- PATCH 2: Clarified SIE control block vs SIE instruction (thanks
Janosch)
- PATCH 3: Make use of CAP_TO_MASK(CAP_SYS_ADMIN) instead of custom
define (thanks Janosch)
Removed Reviewed-By: Claudio
- PATCH 4: Remove erroneous 1MB offset from self->base_hva (thanks
Janosch)
- PATCH 6-8: Change name of test program _pgm to _asm to prevent confusion
- PATCH 10: Move KVM_S390_UCONTROL default option to actual debug config
(thanks Christian)
v2:
- add ucontrol to s390 debug config (new patch)
- PATCH 2: changed atomic_t to __u32 (thanks Claudio)
- PATCH 4: reformatted comment in FIXTURE_SETUP(uc_kvm)
- PATCH 5: refactored to display 8 byte blocks + more internal reuse
(thanks Claudio)
- PATCH 7: make use of more declarative defines instead of magic values
- PATCH 8: make use of more declarative defines instead of magic values
(thanks Claudio)
- PATCH 9: add reference to fix verified by the test case
Christoph Schlameuss (10):
selftests: kvm: s390: Define page sizes in shared header
selftests: kvm: s390: Add kvm_s390_sie_block definition for userspace
tests
selftests: kvm: s390: Add s390x ucontrol test suite with hpage test
selftests: kvm: s390: Add test fixture and simple VM setup tests
selftests: kvm: s390: Add debug print functions
selftests: kvm: s390: Add VM run test case
selftests: kvm: s390: Add uc_map_unmap VM test case
selftests: kvm: s390: Add uc_skey VM test case
selftests: kvm: s390: Verify reject memory region operations for
ucontrol VMs
s390: Enable KVM_S390_UCONTROL config in debug_defconfig
arch/s390/configs/debug_defconfig | 1 +
tools/testing/selftests/kvm/.gitignore | 1 +
tools/testing/selftests/kvm/Makefile | 1 +
.../selftests/kvm/include/s390x/debug_print.h | 69 ++
.../selftests/kvm/include/s390x/processor.h | 5 +
.../testing/selftests/kvm/include/s390x/sie.h | 240 +++++++
.../selftests/kvm/lib/s390x/processor.c | 10 +-
tools/testing/selftests/kvm/s390x/cmma_test.c | 7 +-
tools/testing/selftests/kvm/s390x/config | 2 +
.../testing/selftests/kvm/s390x/debug_test.c | 4 +-
tools/testing/selftests/kvm/s390x/memop.c | 4 +-
tools/testing/selftests/kvm/s390x/tprot.c | 5 +-
.../selftests/kvm/s390x/ucontrol_test.c | 598 ++++++++++++++++++
13 files changed, 931 insertions(+), 16 deletions(-)
create mode 100644 tools/testing/selftests/kvm/include/s390x/debug_print.h
create mode 100644 tools/testing/selftests/kvm/include/s390x/sie.h
create mode 100644 tools/testing/selftests/kvm/s390x/config
create mode 100644 tools/testing/selftests/kvm/s390x/ucontrol_test.c
base-commit: de9c2c66ad8e787abec7c9d7eff4f8c3cdd28aed
--
2.45.2
This test doesn't have support for other architectures. Altough resctrl
is supported on x86 and ARM, but arch_supports_noncont_cat() shows that
only x86 for AMD and Intel are supported by the test. We get build
errors when built for ARM and ARM64.
Hence add support in the Makefile to build this suite only for x86 and
x86_64 architectures.
Fixes: b733143cc455 ("selftests/resctrl: Make resctrl_tests run using kselftest framework")
Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
---
tools/testing/selftests/resctrl/Makefile | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile
index f408bd6bfc3d4..d5cf96315ef9b 100644
--- a/tools/testing/selftests/resctrl/Makefile
+++ b/tools/testing/selftests/resctrl/Makefile
@@ -3,7 +3,9 @@
CFLAGS = -g -Wall -O2 -D_FORTIFY_SOURCE=2
CFLAGS += $(KHDR_INCLUDES)
+ifeq ($(ARCH),$(filter $(ARCH),x86 x86_64))
TEST_GEN_PROGS := resctrl_tests
+endif
LOCAL_HDRS += $(wildcard *.h)
--
2.39.2
There are multiple possible timer sources which could be useful for
the sound stream synchronization: hrtimers, hardware clocks (e.g. PTP),
timer wheels (jiffies). Currently, using one of them to synchronize
the audio stream of snd-aloop module would require writing a
kernel-space driver which exports an ALSA timer through the
snd_timer interface.
However, it is not really convenient for application developers, who may
want to define their custom timer sources for audio synchronization.
For instance, we could have a network application which receives frames
and sends them to snd-aloop pcm device, and another application
listening on the other end of snd-aloop. It makes sense to transfer a
new period of data only when certain amount of frames is received
through the network, but definitely not when a certain amount of jiffies
on a local system elapses. Since all of the devices are purely virtual
it won't introduce any glitches and will help the application developers
to avoid using sample-rate conversion.
This patch series introduces userspace-driven ALSA timers: virtual
timers which are created and controlled from userspace. The timer can
be created from the userspace using the new ioctl SNDRV_TIMER_IOCTL_CREATE.
After creating a timer, it becomes available for use system-wide, so it
can be passed to snd-aloop as a timer source (timer_source parameter
would be "-1.SNDRV_TIMER_GLOBAL_UDRIVEN.{timer_id}"). When the userspace
app decides to trigger a timer, it calls another ioctl
SNDRV_TIMER_IOCTL_TRIGGER on the file descriptor of a timer. It
initiates a transfer of a new period of data.
Userspace-driven timers are associated with file descriptors. If the
application wishes to destroy the timer, it can simply release the file
descriptor of a virtual timer.
I believe introducing new ioctl calls is quite inconvenient (as we have
a limited amount of them), but other possible ways of app <-> kernel
communication (like virtual FS) seem completely inappropriate for this
task (but I'd love to discuss alternative solutions).
This patch series also updates the snd-aloop module so the global timers
can be used as a timer_source for it (it allows using userspace-driven
timers as timer source).
V1 -> V2:
- Fix some problems found by Christophe Jaillet
<christophe.jaillet(a)wanadoo.fr>
V2 -> V3:
- Add improvements suggested by Takashi Iwai <tiwai(a)suse.de>
V3 -> V4:
- Address comments from Jaroslav Kysela <perex(a)perex.cz> and Mark Brown
<broonie(a)kernel.org>
Please, find the patch-specific changelog in the following patches.
Ivan Orlov (4):
ALSA: aloop: Allow using global timers
Docs/sound: Add documentation for userspace-driven ALSA timers
ALSA: timer: Introduce virtual userspace-driven timers
selftests: ALSA: Cover userspace-driven timers with test
Documentation/sound/index.rst | 1 +
Documentation/sound/utimers.rst | 125 ++++++++++++
include/uapi/sound/asound.h | 16 +-
sound/core/Kconfig | 10 +
sound/core/timer.c | 210 ++++++++++++++++++++
sound/drivers/aloop.c | 2 +
tools/testing/selftests/alsa/Makefile | 4 +-
tools/testing/selftests/alsa/global-timer.c | 87 ++++++++
tools/testing/selftests/alsa/utimer-test.c | 164 +++++++++++++++
9 files changed, 616 insertions(+), 3 deletions(-)
create mode 100644 Documentation/sound/utimers.rst
create mode 100644 tools/testing/selftests/alsa/global-timer.c
create mode 100644 tools/testing/selftests/alsa/utimer-test.c
--
2.34.1