From nobody Fri Dec 19 04:16:38 2025 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 500972505C2; Mon, 24 Mar 2025 07:14:59 +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=1742800500; cv=none; b=a4YNmITPiEdY508PH03PufbjpOiPFSjlFnW7DBAQPMF4pWIvaj4+BwttrsDfl1tSIggL5QuYxJPUs2w9MZZrhBM9buqK0D7O3hiHtGLbON333fPA1iX1R77LVCefjL3EYBK1fTvHoXXNS/8WSM++/vR/Pg5kMAX/Yhcfr1rZlQ4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742800500; c=relaxed/simple; bh=PKa3zoVaphNmxES1mu8sRdzUr9GoOg0wu/NaPlC6DGI=; h=From:To:Cc:Subject:Date:Message-Id; b=XjaX2UaVa6nsrbhFbvK6sbx2ZNelyzCNIiJXlEHey/E73YLGg610hrREYfXVaZWAQq1d3Diu7A3ZKnAHXqpZHu7LNuMFYTBraEuTfQXQxAONMZGHp7vD4svUllIiJ5ZVStcGgVhHIHovZMFrTCpvgbs8mB9NE50s2nLH3PMPmv8= 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=GvWUJxd2; 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="GvWUJxd2" Received: by linux.microsoft.com (Postfix, from userid 1134) id BEB182036571; Mon, 24 Mar 2025 00:14:53 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com BEB182036571 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1742800493; bh=uTGr0WIymJiONKq41/5qrDmVxnOqzeOtFmJlRbTVln4=; h=From:To:Cc:Subject:Date:From; b=GvWUJxd25qxb1PfzpwAI/9XKOEGfTqmMyEdOyfcqDICLxVJcNH53WvbLOUdU3X8w+ aDyldzjVYRbm0sgfCjYM9ylMUn5cJwo71IS4p1onO49hTWveHXK6e2ISLvBCPrbVaQ p1guu84DpbDtOV/Jrdo3OXTHUMo6CukWBvf5optc= 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] hv/hv_kvp_daemon: Enable debug logs for hv_kvp_daemon Date: Mon, 24 Mar 2025 00:14:52 -0700 Message-Id: <1742800492-25911-1-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 /var/log/kvp_debug_file.log. This information comes in handy for debugging issues where the key-value pairs for certain pools show mismatch/incorrect values. Signed-off-by: Shradha Gupta --- tools/hv/hv_kvp_daemon.c | 120 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 112 insertions(+), 8 deletions(-) diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index 04ba035d67e9..1f8b02b17356 100644 --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -41,6 +41,7 @@ #include #include #include +#include =20 /* * KVP protocol: The user mode component first registers with the @@ -83,6 +84,7 @@ enum { }; =20 static int in_hand_shake; +static int debug_enabled; =20 static char *os_name =3D ""; static char *os_major =3D ""; @@ -91,6 +93,7 @@ static char *processor_arch; static char *os_build; static char *os_version; static char *lic_version =3D "Unknown version"; +static char debug_file[PATH_MAX]; static char full_domain_name[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; static struct utsname uts_buf; =20 @@ -99,6 +102,7 @@ static struct utsname uts_buf; */ =20 #define KVP_CONFIG_LOC "/var/lib/hyperv" +#define KVP_DEBUG_LOC "/var/log/" =20 #ifndef KVP_SCRIPTS_PATH #define KVP_SCRIPTS_PATH "/usr/libexec/hypervkvpd/" @@ -153,6 +157,16 @@ static void kvp_release_lock(int pool) } } =20 +static void convert_tm_to_string(char *tm_str, size_t tm_str_size) +{ + struct tm tm; + time_t t; + + time(&t); + gmtime_r(&t, &tm); + strftime(tm_str, tm_str_size, "%Y-%m-%dT%H:%M:%S", &tm); +} + static void kvp_update_file(int pool) { FILE *filep; @@ -183,6 +197,45 @@ static void kvp_update_file(int pool) kvp_release_lock(pool); } =20 +static void kvp_dump_initial_pools(int pool) +{ + FILE *debug_filep; + char tm_str[50]; + int i, ret; + + convert_tm_to_string(tm_str, sizeof(tm_str)); + + debug_filep =3D fopen(debug_file, "a"); + if (!debug_filep) { + syslog(LOG_ERR, "Failed to open file: %s, pool: %d; error: %d%s", + debug_file, pool, errno, strerror(errno)); + return; + } + + ret =3D fprintf(debug_filep, "=3D=3D=3DStart dumping the contents on pool= %d =3D=3D=3D\n", + pool); + if (ret <=3D 0) { + syslog(LOG_ERR, "Failed to write to kvp debug file: %d", pool); + fclose(debug_filep); + return; + } + + for (i =3D 0; i < kvp_file_info[pool].num_records; i++) { + ret =3D fprintf(debug_filep, "[%s]: pool: %d, %d/%d key=3D%s val=3D%s\n", + tm_str, pool, i, kvp_file_info[pool].num_records, + kvp_file_info[pool].records[i].key, + kvp_file_info[pool].records[i].value); + + if (ret <=3D 0) { + syslog(LOG_ERR, "Failed to write to kvp debug file: pool=3D%d, i=3D%u/%= u", + pool, i, kvp_file_info[pool].num_records); + break; + } + } + + fclose(debug_filep); +} + static void kvp_update_mem_state(int pool) { FILE *filep; @@ -270,6 +323,8 @@ 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; @@ -321,14 +376,37 @@ static int kvp_key_delete(int pool, const __u8 *key, = int key_size) 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; + FILE *filep =3D NULL; + int num_records; + char tm_str[50]; int num_blocks; + int i; + + if (debug_enabled) { + filep =3D fopen(debug_file, "a"); + if (!filep) { + syslog(LOG_ERR, "Failed to open file %s; error: %d", + debug_file, errno); + } else { + convert_tm_to_string(tm_str, sizeof(tm_str)); + fprintf(filep, "[%s]:%s: got a KVP: pool=3D%d key=3D%s val=3D%s\n", + __func__, tm_str, 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 (filep) { + fprintf(filep, "[%s]: Got a too long key or value: pool=3D%d, key=3D%s,= val=3D%s\n", + tm_str, pool, key, value); + fclose(filep); + } return 1; + } =20 /* * First update the in-memory state. @@ -348,6 +426,11 @@ 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 (filep) { + fprintf(filep, "[%s]:%s: updated: pool=3D%d key=3D%s val=3D%s\n", + __func__, tm_str, pool, key, value); + fclose(filep); + } return 0; } =20 @@ -359,8 +442,12 @@ 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) { + if (filep) + fclose(filep); + syslog(LOG_ERR, "%s: Memory alloc failure", __func__); return 1; + } kvp_file_info[pool].num_blocks++; =20 } @@ -368,6 +455,12 @@ 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 (filep) { + fprintf(filep, "[%s]:%s: added: pool=3D%d key=3D%s val=3D%s\n", + __func__, tm_str, pool, key, value); + fclose(filep); + } kvp_update_file(pool); return 0; } @@ -1662,6 +1755,7 @@ 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\n" " -h, --help print this help\n", argv[0]); } =20 @@ -1681,12 +1775,13 @@ 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 +1790,9 @@ 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 +1815,12 @@ int main(int argc, char *argv[]) */ kvp_get_domain_name(full_domain_name, sizeof(full_domain_name)); =20 + if (debug_enabled) { + sprintf(debug_file, "%s%s", KVP_DEBUG_LOC, "kvp_debug_file.log"); + syslog(LOG_INFO, "Logging debug info in kvp_debug_file=3D%s", + debug_file); + } + if (kvp_file_init()) { syslog(LOG_ERR, "Failed to initialize the pools"); exit(EXIT_FAILURE); --=20 2.34.1