Currently the QEMU processes inherit their core dump rlimit from libvirtd, which is really suboptimal. This change allows their limit to be directly controller from qemu.conf instead. --- Changed in v2: - Allow use of string "unlimited" src/libvirt_private.syms | 2 ++ src/qemu/libvirtd_qemu.aug | 1 + src/qemu/qemu.conf | 16 +++++++++++++++- src/qemu/qemu_conf.c | 17 +++++++++++++++++ src/qemu/qemu_conf.h | 1 + src/qemu/qemu_process.c | 1 + src/qemu/test_libvirtd_qemu.aug.in | 1 + src/util/vircommand.c | 14 ++++++++++++++ src/util/vircommand.h | 1 + src/util/virprocess.c | 36 ++++++++++++++++++++++++++++++++++++ src/util/virprocess.h | 1 + 11 files changed, 90 insertions(+), 1 deletion(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 597ce5f..773d935 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1371,6 +1371,7 @@ virCommandSetErrorFD; virCommandSetGID; virCommandSetInputBuffer; virCommandSetInputFD; +virCommandSetMaxCoreSize; virCommandSetMaxFiles; virCommandSetMaxMemLock; virCommandSetMaxProcesses; @@ -2180,6 +2181,7 @@ virProcessRunInMountNamespace; virProcessSchedPolicyTypeFromString; virProcessSchedPolicyTypeToString; virProcessSetAffinity; +virProcessSetMaxCoreSize; virProcessSetMaxFiles; virProcessSetMaxMemLock; virProcessSetMaxProcesses; diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug index 8bc23ba..a8edc2b 100644 --- a/src/qemu/libvirtd_qemu.aug +++ b/src/qemu/libvirtd_qemu.aug @@ -72,6 +72,7 @@ module Libvirtd_qemu = | bool_entry "set_process_name" | int_entry "max_processes" | int_entry "max_files" + | int_entry "max_core" | str_entry "stdio_handler" let device_entry = bool_entry "mac_filter" diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf index 7964273..fac33ec 100644 --- a/src/qemu/qemu.conf +++ b/src/qemu/qemu.conf @@ -401,7 +401,21 @@ #max_processes = 0 #max_files = 0 - +# If max_core is set to a positive integer, then QEMU will be +# permitted to create core dumps when it crashes, provided its +# RAM size is smaller than the limit set. Be warned that the +# core dump will include a full copy of the guest RAM, so if +# the largest guest is 32 GB in size, the max_core limit will +# have to be at least 33/34 GB to allow enough overhead. +# +# As a special case it can be set to the string "unlimited" to +# to allow arbitrarily sized core dumps. +# +# By default the core dump size is set to 0 disabling all dumps +# +# Size is in bytes or string "unlimited" +#max_core = 0 +#max_core = "unlimited" # mac_filter enables MAC addressed based filtering on bridge ports. # This currently requires ebtables to be installed. diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index fa9d65e..45d039c 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -393,6 +393,7 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg, char **controllers = NULL; char **hugetlbfs = NULL; char **nvram = NULL; + char *corestr = NULL; /* Just check the file is readable before opening it, otherwise * libvirt emits an error. @@ -633,6 +634,21 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg, if (virConfGetValueUInt(conf, "max_files", &cfg->maxFiles) < 0) goto cleanup; + if (virConfGetValueType(conf, "max_core") == VIR_CONF_STRING) { + if (virConfGetValueString(conf, "max_core", &corestr) < 0) + goto cleanup; + if (STREQ(corestr, "unlimited")) { + cfg->maxCore = ULLONG_MAX; + } else { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Unknown core size '%s'"), + corestr); + goto cleanup; + } + } else if (virConfGetValueULLong(conf, "max_core", &cfg->maxCore) < 0) { + goto cleanup; + } + if (virConfGetValueString(conf, "lock_manager", &cfg->lockManagerName) < 0) goto cleanup; if (virConfGetValueString(conf, "stdio_handler", &stdioHandler) < 0) @@ -715,6 +731,7 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg, virStringFreeList(controllers); virStringFreeList(hugetlbfs); virStringFreeList(nvram); + VIR_FREE(corestr); VIR_FREE(user); VIR_FREE(group); virConfFree(conf); diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index 510cd9a..b730202 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -148,6 +148,7 @@ struct _virQEMUDriverConfig { unsigned int maxProcesses; unsigned int maxFiles; + unsigned long long maxCore; unsigned int maxQueuedJobs; diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 4adb14e..a7cbd59 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -5069,6 +5069,7 @@ qemuProcessLaunch(virConnectPtr conn, virCommandSetPreExecHook(cmd, qemuProcessHook, &hookData); virCommandSetMaxProcesses(cmd, cfg->maxProcesses); virCommandSetMaxFiles(cmd, cfg->maxFiles); + virCommandSetMaxCoreSize(cmd, cfg->maxCore); virCommandSetUmask(cmd, 0x002); VIR_DEBUG("Setting up security labelling"); diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in index c4d4f19..c3d6da5 100644 --- a/src/qemu/test_libvirtd_qemu.aug.in +++ b/src/qemu/test_libvirtd_qemu.aug.in @@ -62,6 +62,7 @@ module Test_libvirtd_qemu = { "set_process_name" = "1" } { "max_processes" = "0" } { "max_files" = "0" } +{ "max_core" = "0" } { "mac_filter" = "1" } { "relaxed_acs_check" = "1" } { "allow_disk_format_probing" = "1" } diff --git a/src/util/vircommand.c b/src/util/vircommand.c index f5bd7af..6baa37a 100644 --- a/src/util/vircommand.c +++ b/src/util/vircommand.c @@ -124,6 +124,8 @@ struct _virCommand { unsigned long long maxMemLock; unsigned int maxProcesses; unsigned int maxFiles; + bool setMaxCore; + unsigned long long maxCore; uid_t uid; gid_t gid; @@ -687,6 +689,9 @@ virExec(virCommandPtr cmd) goto fork_error; if (virProcessSetMaxFiles(0, cmd->maxFiles) < 0) goto fork_error; + if (cmd->setMaxCore && + virProcessSetMaxCoreSize(0, cmd->maxCore) < 0) + goto fork_error; if (cmd->hook) { VIR_DEBUG("Run hook %p %p", cmd->hook, cmd->opaque); @@ -1105,6 +1110,15 @@ virCommandSetMaxFiles(virCommandPtr cmd, unsigned int files) cmd->maxFiles = files; } +void virCommandSetMaxCoreSize(virCommandPtr cmd, unsigned long long bytes) +{ + if (!cmd || cmd->has_error) + return; + + cmd->maxCore = bytes; + cmd->setMaxCore = true; +} + void virCommandSetUmask(virCommandPtr cmd, int mask) { if (!cmd || cmd->has_error) diff --git a/src/util/vircommand.h b/src/util/vircommand.h index 44818ef..99dcdeb 100644 --- a/src/util/vircommand.h +++ b/src/util/vircommand.h @@ -75,6 +75,7 @@ void virCommandSetUID(virCommandPtr cmd, uid_t uid); void virCommandSetMaxMemLock(virCommandPtr cmd, unsigned long long bytes); void virCommandSetMaxProcesses(virCommandPtr cmd, unsigned int procs); void virCommandSetMaxFiles(virCommandPtr cmd, unsigned int files); +void virCommandSetMaxCoreSize(virCommandPtr cmd, unsigned long long bytes); void virCommandSetUmask(virCommandPtr cmd, int umask); void virCommandClearCaps(virCommandPtr cmd); diff --git a/src/util/virprocess.c b/src/util/virprocess.c index 09dd3c9..2b71445 100644 --- a/src/util/virprocess.c +++ b/src/util/virprocess.c @@ -914,6 +914,42 @@ virProcessSetMaxFiles(pid_t pid ATTRIBUTE_UNUSED, unsigned int files) } #endif /* ! (HAVE_SETRLIMIT && defined(RLIMIT_NOFILE)) */ +#if HAVE_SETRLIMIT && defined(RLIMIT_CORE) +int +virProcessSetMaxCoreSize(pid_t pid, unsigned long long bytes) +{ + struct rlimit rlim; + + rlim.rlim_cur = rlim.rlim_max = bytes; + if (pid == 0) { + if (setrlimit(RLIMIT_CORE, &rlim) < 0) { + virReportSystemError(errno, + _("cannot limit core file size to %llu"), + bytes); + return -1; + } + } else { + if (virProcessPrLimit(pid, RLIMIT_CORE, &rlim, NULL) < 0) { + virReportSystemError(errno, + _("cannot limit core file size " + "of process %lld to %llu"), + (long long int)pid, bytes); + return -1; + } + } + return 0; +} +#else /* ! (HAVE_SETRLIMIT && defined(RLIMIT_CORE)) */ +int +virProcessSetMaxCoreSize(pid_t pid ATTRIBUTE_UNUSED, + unsigned long long bytes ATTRIBUTE_UNUSED) +{ + virReportSystemError(ENOSYS, "%s", _("Not supported on this platform")); + return -1; +} +#endif /* ! (HAVE_SETRLIMIT && defined(RLIMIT_CORE)) */ + + #ifdef __linux__ /* * Port of code from polkitunixprocess.c under terms diff --git a/src/util/virprocess.h b/src/util/virprocess.h index a7a1fe9..04e9802 100644 --- a/src/util/virprocess.h +++ b/src/util/virprocess.h @@ -75,6 +75,7 @@ int virProcessSetNamespaces(size_t nfdlist, int virProcessSetMaxMemLock(pid_t pid, unsigned long long bytes); int virProcessSetMaxProcesses(pid_t pid, unsigned int procs); int virProcessSetMaxFiles(pid_t pid, unsigned int files); +int virProcessSetMaxCoreSize(pid_t pid, unsigned long long bytes); int virProcessGetMaxMemLock(pid_t pid, unsigned long long *bytes); -- 2.7.4