From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- tools/testing/vsock/README | 86 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 tools/testing/vsock/README (limited to 'tools/testing/vsock/README') diff --git a/tools/testing/vsock/README b/tools/testing/vsock/README new file mode 100644 index 000000000..680ce666c --- /dev/null +++ b/tools/testing/vsock/README @@ -0,0 +1,86 @@ +AF_VSOCK test suite +------------------- +These tests exercise net/vmw_vsock/ host<->guest sockets for VMware, KVM, and +Hyper-V. + +The following tests are available: + + * vsock_test - core AF_VSOCK socket functionality + * vsock_diag_test - vsock_diag.ko module for listing open sockets + +The following prerequisite steps are not automated and must be performed prior +to running tests: + +1. Build the kernel, make headers_install, and build these tests. +2. Install the kernel and tests on the host. +3. Install the kernel and tests inside the guest. +4. Boot the guest and ensure that the AF_VSOCK transport is enabled. + +Invoke test binaries in both directions as follows: + + # host=server, guest=client + (host)# $TEST_BINARY --mode=server \ + --control-port=1234 \ + --peer-cid=3 + (guest)# $TEST_BINARY --mode=client \ + --control-host=$HOST_IP \ + --control-port=1234 \ + --peer-cid=2 + + # host=client, guest=server + (guest)# $TEST_BINARY --mode=server \ + --control-port=1234 \ + --peer-cid=2 + (host)# $TEST_BINARY --mode=client \ + --control-port=$GUEST_IP \ + --control-port=1234 \ + --peer-cid=3 + +Some tests are designed to produce kernel memory leaks. Leaks detection, +however, is deferred to Kernel Memory Leak Detector. It is recommended to enable +kmemleak (CONFIG_DEBUG_KMEMLEAK=y) and explicitly trigger a scan after each test +suite run, e.g. + + # echo clear > /sys/kernel/debug/kmemleak + # $TEST_BINARY ... + # echo "wait for any grace periods" && sleep 2 + # echo scan > /sys/kernel/debug/kmemleak + # echo "wait for kmemleak" && sleep 5 + # echo scan > /sys/kernel/debug/kmemleak + # cat /sys/kernel/debug/kmemleak + +For more information see Documentation/dev-tools/kmemleak.rst. + +vsock_perf utility +------------------- +'vsock_perf' is a simple tool to measure vsock performance. It works in +sender/receiver modes: sender connect to peer at the specified port and +starts data transmission to the receiver. After data processing is done, +it prints several metrics(see below). + +Usage: +# run as sender +# connect to CID 2, port 1234, send 1G of data, tx buf size is 1M +./vsock_perf --sender 2 --port 1234 --bytes 1G --buf-size 1M + +Output: +tx performance: A Gbits/s + +Output explanation: +A is calculated as "number of bits to send" / "time in tx loop" + +# run as receiver +# listen port 1234, rx buf size is 1M, socket buf size is 1G, SO_RCVLOWAT is 64K +./vsock_perf --port 1234 --buf-size 1M --vsk-size 1G --rcvlowat 64K + +Output: +rx performance: A Gbits/s +total in 'read()': B sec +POLLIN wakeups: C +average in 'read()': D ns + +Output explanation: +A is calculated as "number of received bits" / "time in rx loop". +B is time, spent in 'read()' system call(excluding 'poll()') +C is number of 'poll()' wake ups with POLLIN bit set. +D is B / C, e.g. average amount of time, spent in single 'read()'. -- cgit v1.3.1