From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6B3B2C3F2CD for ; Wed, 4 Mar 2020 09:12:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3DB332072D for ; Wed, 4 Mar 2020 09:12:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Vtq61F8O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbgCDJM1 (ORCPT ); Wed, 4 Mar 2020 04:12:27 -0500 Received: from mail-lf1-f66.google.com ([209.85.167.66]:42511 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726137AbgCDJM0 (ORCPT ); Wed, 4 Mar 2020 04:12:26 -0500 Received: by mail-lf1-f66.google.com with SMTP id t21so862936lfe.9 for ; Wed, 04 Mar 2020 01:12:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=OwW2M4vLJx3K6cWfp/7SWMlbw3i16QmqwaxJCzTzYlE=; b=Vtq61F8O1YRQ2Aoh+lnz0OwtJjTfjQTyZ0bz+UwVG8++THM0ihJJccL/coNF0u/uZv HC1Fl184q/D5lilWIPJ+SLo8MN2/SaHGvERPE8tO86bWtFK+4e+vA+GJFvWkKpUc3f04 JFyTQbq7gbnMtl4lSzmYsNhVHQO3FDNtClY6865lhhzAtiYGf3GTAfa62I5LAZIvfiz3 deKocZi9Nqk9t9xUXH960U8dylpYENZzimOklx69b5xaOPUxxN7tKBfPVSz2u0TKZmd6 ZqcI1U/BYeWtOW9UVNYdkCHFG1P3vpHwLgNCWJ10wdY1Q1Lp3QMpnM1UeB+Jkc1nM/lN SpYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=OwW2M4vLJx3K6cWfp/7SWMlbw3i16QmqwaxJCzTzYlE=; b=Ob/cC+EXeg5RvGzRkDK/wa9ws+Gr95nCJ29kHJfvzUosjfn4g9fsET1bsGCemRpPva /nIrnV1urkXn4hAK9rymfrZXJpeluMj9QEG4QNSz+Y8D0GHZEjnQO1xhe+G+WupYx0FJ HDh5s7CXUDAiFBox8zVCnbqHnbATswQF79d9GNNK4iWpq/fVF0/TC2uL8bBNX6xM0MXA dm82n3GbEawsB7yPr4Aui9ylgzhxgk4osuluyJ33aWTxFZw+EiNDOI3Fdl0js1xC3/v0 uhH+qRZre5fhIgKCTEzkjrcf3ahhOAvwB7YFyDwofx8KSm1rOUwv4lt+423uyWbwyp+O JvcQ== X-Gm-Message-State: ANhLgQ1imMfIQaPLtnSolegkgpx3e4uZEPAPS3lNSZ3jy5WSZNR8ivMb CzHbXIDgHSLb9t+S2eHzMPU= X-Google-Smtp-Source: ADFU+vvor2NhbIJ9CF7mdExFW/XqvfIjIMVsMQDPrQzgm1scaNP1CYk5HuAWlDPIhQCRu0rzL422Mg== X-Received: by 2002:a19:ed08:: with SMTP id y8mr1447156lfy.56.1583313143980; Wed, 04 Mar 2020 01:12:23 -0800 (PST) Received: from oberon.eng.vmware.com ([146.247.46.5]) by smtp.gmail.com with ESMTPSA id v15sm13327462lfg.51.2020.03.04.01.12.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Mar 2020 01:12:23 -0800 (PST) From: "Tzvetomir Stoyanov (VMware)" To: rostedt@goodmis.org Cc: linux-trace-devel@vger.kernel.org Subject: [PATCH v22 01/13] trace-cmd: Find and store pids of tasks, which run virtual CPUs of given VM Date: Wed, 4 Mar 2020 11:12:08 +0200 Message-Id: <20200304091220.30936-2-tz.stoyanov@gmail.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200304091220.30936-1-tz.stoyanov@gmail.com> References: <20200304091220.30936-1-tz.stoyanov@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: Tzvetomir Stoyanov In order to match host and guest events, a mapping between guest VCPU and the host task, running this VCPU is needed. Extended existing struct guest to hold such mapping and added logic in read_qemu_guests() function to initialize it. Implemented a new internal API, get_guest_vcpu_pid(), to retrieve VCPU-task mapping for given VM. Signed-off-by: Tzvetomir Stoyanov --- tracecmd/include/trace-local.h | 2 + tracecmd/trace-record.c | 85 ++++++++++++++++++++++++++++++++++ 2 files changed, 87 insertions(+) diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h index 29f27793..a5cf0640 100644 --- a/tracecmd/include/trace-local.h +++ b/tracecmd/include/trace-local.h @@ -247,6 +247,8 @@ void update_first_instance(struct buffer_instance *instance, int topt); void show_instance_file(struct buffer_instance *instance, const char *name); +int get_guest_vcpu_pid(unsigned int guest_cid, unsigned int guest_vcpu); + /* moved from trace-cmd.h */ void tracecmd_create_top_instance(char *name); void tracecmd_remove_instances(void); diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c index 0a3851ad..9ed79856 100644 --- a/tracecmd/trace-record.c +++ b/tracecmd/trace-record.c @@ -3035,11 +3035,32 @@ struct guest { char *name; int cid; int pid; + int cpu_max; + int *cpu_pid; }; static struct guest *guests; static size_t guests_len; +static int set_vcpu_pid_mapping(struct guest *guest, int cpu, int pid) +{ + int *cpu_pid; + int i; + + if (cpu >= guest->cpu_max) { + cpu_pid = realloc(guest->cpu_pid, (cpu + 1) * sizeof(int)); + if (!cpu_pid) + return -1; + /* Handle sparse CPU numbers */ + for (i = guest->cpu_max; i < cpu; i++) + cpu_pid[i] = -1; + guest->cpu_max = cpu + 1; + guest->cpu_pid = cpu_pid; + } + guest->cpu_pid[cpu] = pid; + return 0; +} + static char *get_qemu_guest_name(char *arg) { char *tok, *end = arg; @@ -3052,6 +3073,50 @@ static char *get_qemu_guest_name(char *arg) return arg; } +static int read_qemu_guests_pids(char *guest_task, struct guest *guest) +{ + struct dirent *entry; + char path[PATH_MAX]; + char *buf = NULL; + size_t n = 0; + int ret = 0; + long vcpu; + long pid; + DIR *dir; + FILE *f; + + snprintf(path, sizeof(path), "/proc/%s/task", guest_task); + dir = opendir(path); + if (!dir) + return -1; + + while (!ret && (entry = readdir(dir))) { + if (!(entry->d_type == DT_DIR && is_digits(entry->d_name))) + continue; + + snprintf(path, sizeof(path), "/proc/%s/task/%s/comm", + guest_task, entry->d_name); + f = fopen(path, "r"); + if (!f) + continue; + + if (getline(&buf, &n, f) >= 0 && + strncmp(buf, "CPU ", 4) == 0) { + vcpu = strtol(buf + 4, NULL, 10); + pid = strtol(entry->d_name, NULL, 10); + if (vcpu < INT_MAX && pid < INT_MAX && + vcpu >= 0 && pid >= 0) { + if (set_vcpu_pid_mapping(guest, vcpu, pid)) + ret = 1; + } + } + + fclose(f); + } + free(buf); + return ret; +} + static void read_qemu_guests(void) { static bool initialized; @@ -3115,6 +3180,10 @@ static void read_qemu_guests(void) if (!is_qemu) goto next; + if (read_qemu_guests_pids(entry->d_name, &guest)) + warning("Failed to retrieve VPCU - PID mapping for guest %s", + guest.name ? guest.name : "Unknown"); + guests = realloc(guests, (guests_len + 1) * sizeof(*guests)); if (!guests) die("Can not allocate guest buffer"); @@ -3160,6 +3229,22 @@ static char *parse_guest_name(char *guest, int *cid, int *port) return guest; } +int get_guest_vcpu_pid(unsigned int guest_cid, unsigned int guest_vcpu) +{ + int i; + + if (!guests) + return -1; + + for (i = 0; i < guests_len; i++) { + if (guests[i].cpu_pid < 0 || guest_vcpu >= guests[i].cpu_max) + continue; + if (guest_cid == guests[i].cid) + return guests[i].cpu_pid[guest_vcpu]; + } + return -1; +} + static void set_prio(int prio) { struct sched_param sp; -- 2.24.1