From nobody Sat Feb 7 21:16:03 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4C2BE219FC; Sun, 6 Apr 2025 08:48:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743929296; cv=none; b=aMHzHDGihOxU4UkDAEbcoDovOdMryVPLpRAh51KuQH26Sfuj0jTqGisSyfflV0DXfbonQpZF3ynOSMCdeJSUDOSwVFU0HmyU5JCH/hcF8614Y+mqsyvbxS4vqsLTD0Ok6HegiWC1kZERKuMOJeLpeaBYE0uByh6BZR3wHQK0XDw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743929296; c=relaxed/simple; bh=cZogAL37BrditkuA6/iID0XEzaJF/kRmnZNyepXySaQ=; h=From:To:Cc:Subject:Date:Message-Id; b=AtR45BjqweTjYL2SMCv7tqsjvGA0ulDXcqaiAF1SYvupVTiHDKcIWuAeJRXE4gMIjrxDEdd3x6TEWgvGdtHXggbZIH8BapK5IypNqsVZ/ovvXtWPmtvIGj4QMYlJWb7EmmgSHk5qxPF1dXrc87t0YF1eCZjkTQ9kWTkl9kOWT1g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=TGDTVr0H; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="TGDTVr0H" Received: by linux.microsoft.com (Postfix, from userid 1134) id 627AB2112533; Sun, 6 Apr 2025 01:48:09 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 627AB2112533 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1743929289; bh=wSGP4SJBUnsmhJUgOkT/omo/JNKbUWLMShPZLni6L/c=; h=From:To:Cc:Subject:Date:From; b=TGDTVr0Hz/oA1h9jG8IHPffo/IZu5+hU/tW/JAwhed5t0W3JgVP0wmStiPIyGqNMH BAMoymsQT2+0khy98J9tQa4mabz6WFvsg9HoPfPQSiDrBtus9hWBqpCp1lMDF19F0o hqsK3Xd12QC3Z85LngR/Ig6/bUGDSD8k7WJSOjkc= From: Shradha Gupta To: "K. Y. Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Shradha Gupta , Shradha Gupta Subject: [PATCH v3] hv/hv_kvp_daemon: Enable debug logs for hv_kvp_daemon Date: Sun, 6 Apr 2025 01:48:08 -0700 Message-Id: <1743929288-7181-1-git-send-email-shradhagupta@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Allow the KVP daemon to log the KVP updates triggered in the VM with a new debug flag(-d). When the daemon is started with this flag, it logs updates and debug information in syslog with loglevel LOG_DEBUG. This information comes in handy for debugging issues where the key-value pairs for certain pools show mismatch/incorrect values. The distro-vendors can further consume these changes and modify the respective service files to redirect the logs to specific files as needed. Signed-off-by: Shradha Gupta Reviewed-by: Naman Jain --- Changes in v3: * remove timestamp from raw message * use i+1 instead of i while printing record array * add debug logs in delete operation --- Changes in v2: * log the debug logs in syslog(debug) instead of a seperate file that we will have to maintain. * fix the commit message to indicate the same. --- tools/hv/hv_kvp_daemon.c | 71 +++++++++++++++++++++++++++++++++++----- 1 file changed, 63 insertions(+), 8 deletions(-) diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index 04ba035d67e9..7a1b7b0a9233 100644 --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -83,6 +83,7 @@ enum { }; =20 static int in_hand_shake; +static int debug_enabled; =20 static char *os_name =3D ""; static char *os_major =3D ""; @@ -183,6 +184,20 @@ static void kvp_update_file(int pool) kvp_release_lock(pool); } =20 +static void kvp_dump_initial_pools(int pool) +{ + int i; + + syslog(LOG_DEBUG, "=3D=3D=3DStart dumping the contents of pool %d =3D=3D= =3D\n", + pool); + + for (i =3D 0; i < kvp_file_info[pool].num_records; i++) + syslog(LOG_DEBUG, "pool: %d, %d/%d key=3D%s val=3D%s\n", + pool, i + 1, kvp_file_info[pool].num_records, + kvp_file_info[pool].records[i].key, + kvp_file_info[pool].records[i].value); +} + static void kvp_update_mem_state(int pool) { FILE *filep; @@ -270,6 +285,8 @@ static int kvp_file_init(void) return 1; kvp_file_info[i].num_records =3D 0; kvp_update_mem_state(i); + if (debug_enabled) + kvp_dump_initial_pools(i); } =20 return 0; @@ -297,6 +314,9 @@ static int kvp_key_delete(int pool, const __u8 *key, in= t key_size) * Found a match; just move the remaining * entries up. */ + if (debug_enabled) + syslog(LOG_DEBUG, "%s: deleting the KVP: pool=3D%d key=3D%s val=3D%s", + __func__, pool, record[i].key, record[i].value); if (i =3D=3D (num_records - 1)) { kvp_file_info[pool].num_records--; kvp_update_file(pool); @@ -315,20 +335,36 @@ static int kvp_key_delete(int pool, const __u8 *key, = int key_size) kvp_update_file(pool); return 0; } + + if (debug_enabled) + syslog(LOG_DEBUG, "%s: could not delete KVP: pool=3D%d key=3D%s. Record = not found", + __func__, pool, key); + return 1; } =20 static int kvp_key_add_or_modify(int pool, const __u8 *key, int key_size, const __u8 *value, int value_size) { - int i; - int num_records; struct kvp_record *record; + int num_records; int num_blocks; + int i; + + if (debug_enabled) + syslog(LOG_DEBUG, "%s: got a KVP: pool=3D%d key=3D%s val=3D%s", + __func__, pool, key, value); =20 if ((key_size > HV_KVP_EXCHANGE_MAX_KEY_SIZE) || - (value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) + (value_size > HV_KVP_EXCHANGE_MAX_VALUE_SIZE)) { + syslog(LOG_ERR, "Got a too long key or value: key=3D%s, val=3D%s", + key, value); + + if (debug_enabled) + syslog(LOG_DEBUG, "%s: Got a too long key or value: pool=3D%d, key=3D%s= , val=3D%s", + __func__, pool, key, value); return 1; + } =20 /* * First update the in-memory state. @@ -348,6 +384,9 @@ static int kvp_key_add_or_modify(int pool, const __u8 *= key, int key_size, */ memcpy(record[i].value, value, value_size); kvp_update_file(pool); + if (debug_enabled) + syslog(LOG_DEBUG, "%s: updated: pool=3D%d key=3D%s val=3D%s", + __func__, pool, key, value); return 0; } =20 @@ -359,8 +398,10 @@ static int kvp_key_add_or_modify(int pool, const __u8 = *key, int key_size, record =3D realloc(record, sizeof(struct kvp_record) * ENTRIES_PER_BLOCK * (num_blocks + 1)); =20 - if (record =3D=3D NULL) + if (!record) { + syslog(LOG_ERR, "%s: Memory alloc failure", __func__); return 1; + } kvp_file_info[pool].num_blocks++; =20 } @@ -368,6 +409,11 @@ static int kvp_key_add_or_modify(int pool, const __u8 = *key, int key_size, memcpy(record[i].key, key, key_size); kvp_file_info[pool].records =3D record; kvp_file_info[pool].num_records++; + + if (debug_enabled) + syslog(LOG_DEBUG, "%s: added: pool=3D%d key=3D%s val=3D%s", + __func__, pool, key, value); + kvp_update_file(pool); return 0; } @@ -1662,6 +1708,7 @@ void print_usage(char *argv[]) fprintf(stderr, "Usage: %s [options]\n" "Options are:\n" " -n, --no-daemon stay in foreground, don't daemonize\n" + " -d, --debug-enabled Enable debug logs(syslog debug by default)\n" " -h, --help print this help\n", argv[0]); } =20 @@ -1681,12 +1728,13 @@ int main(int argc, char *argv[]) int daemonize =3D 1, long_index =3D 0, opt; =20 static struct option long_options[] =3D { - {"help", no_argument, 0, 'h' }, - {"no-daemon", no_argument, 0, 'n' }, - {0, 0, 0, 0 } + {"help", no_argument, 0, 'h' }, + {"no-daemon", no_argument, 0, 'n' }, + {"debug-enabled", no_argument, 0, 'd' }, + {0, 0, 0, 0 } }; =20 - while ((opt =3D getopt_long(argc, argv, "hn", long_options, + while ((opt =3D getopt_long(argc, argv, "hnd", long_options, &long_index)) !=3D -1) { switch (opt) { case 'n': @@ -1695,6 +1743,9 @@ int main(int argc, char *argv[]) case 'h': print_usage(argv); exit(0); + case 'd': + debug_enabled =3D 1; + break; default: print_usage(argv); exit(EXIT_FAILURE); @@ -1717,6 +1768,9 @@ int main(int argc, char *argv[]) */ kvp_get_domain_name(full_domain_name, sizeof(full_domain_name)); =20 + if (debug_enabled) + syslog(LOG_INFO, "Logging debug info in syslog(debug)"); + if (kvp_file_init()) { syslog(LOG_ERR, "Failed to initialize the pools"); exit(EXIT_FAILURE); --=20 2.34.1