@@ -50,4 +50,17 @@ config CXL_MEM_RAW_COMMANDS
potential impact to memory currently in use by the kernel.
If developing CXL hardware or the driver say Y, otherwise say N.
+
+config CXL_MEM_INSECURE_DEBUG
+ bool "CXL.mem debugging"
+ depends on CXL_MEM
+ help
+ Enable debug of all CXL command payloads.
+
+ Some CXL devices and controllers support encryption and other
+ security features. The payloads for the commands that enable
+ those features may contain sensitive clear-text security
+ material. Disable debug of those command payloads by default.
+ If you are a kernel developer actively working on CXL
+ security enabling say Y, otherwise say N.
endif
@@ -346,6 +346,14 @@ static int __cxl_mem_mbox_send_cmd(struct cxl_mem *cxlm,
/* #5 */
rc = cxl_mem_wait_for_doorbell(cxlm);
+
+ if (!cxl_is_security_command(mbox_cmd->opcode) ||
+ IS_ENABLED(CONFIG_CXL_MEM_INSECURE_DEBUG)) {
+ print_hex_dump_debug("Payload ", DUMP_PREFIX_OFFSET, 16, 1,
+ mbox_cmd->payload_in, mbox_cmd->size_in,
+ true);
+ }
+
if (rc == -ETIMEDOUT) {
cxl_mem_mbox_timeout(cxlm, mbox_cmd);
return rc;
It's often useful in debug scenarios to see what the hardware has dumped out. As it stands today, any device error will result in the payload not being copied out, so there is no way to triage commands which weren't expected to fail (and sometimes the payload may have that information). The functionality is protected by normal kernel security mechanisms as well as a CONFIG option in the CXL driver. This was extracted from the original version of the CXL enabling patch series. Signed-off-by: Ben Widawsky <ben.widawsky@intel.com> --- drivers/cxl/Kconfig | 13 +++++++++++++ drivers/cxl/mem.c | 8 ++++++++ 2 files changed, 21 insertions(+)