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 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2A524C61DD3 for ; Thu, 3 Sep 2026 20:24:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x2Dz5-0008LR-Kt; Thu, 03 Sep 2026 16:24:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x2Dz3-0008Ks-Sn for qemu-devel@nongnu.org; Thu, 03 Sep 2026 16:24:30 -0400 Received: from mx.treblig.org ([2a00:1098:5b::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x2Dz1-0005ZU-5x for qemu-devel@nongnu.org; Thu, 03 Sep 2026 16:24:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=treblig.org ; s=bytemarkmx; h=Content-Type:MIME-Version:Message-ID:Subject:From:Date:From :Subject; bh=plBqrGALcsyoNB0QO82/+M8tHegxcKYidJxbU9bkcdI=; b=T5dUVHh5TUg+0Xdk EpRHVTlEkQtz6WHaHrdowpzPOaB0NOizwIZifg/eW5tsZ4u3uJ/LpZDaq/pWaYkz5SEoUkc76/uqj le61gJ9hNz4qXBbIc88J0kSN++04nJQ/KHtkCU0XWxA3NsgDpIYNUky1N1zPRl7JO/ZrT1HPt5Gix DlVaVk1TnSrJn2ECxcLa4mqXvoNYdTdc8iJqWwNv0gFEgVsWwqpGRTzODAz24kwQMdqiwkDyaXXM+ 94yFvThSYPKXmhAB0V+sBLze7B3Uw2tykW661wza95Ew+/rIgwU5/vWI3BZjbzn0d5P64JXmg1Q5t dx0p9c+c1+vsBW6hSg==; Received: from dg by mx.treblig.org with local (Exim 4.98.2) (envelope-from ) id 1x2Dyx-00000001eks-0X0B; Thu, 03 Sep 2026 20:24:23 +0000 Date: Thu, 3 Sep 2026 20:24:23 +0000 From: "Dr. David Alan Gilbert" To: Peter Xu Cc: Fabiano Rosas , qemu-devel@nongnu.org, Laurent Vivier , Paolo Bonzini Subject: Re: [PATCH 11/18] migration: Use keyval input visitor in HMP set command Message-ID: References: <20260902221547.1812481-1-farosas@suse.de> <20260902221547.1812481-12-farosas@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: X-Chocolate: 70 percent or better cocoa solids preferably X-Operating-System: Linux/6.12.107+deb13-amd64 (x86_64) X-Uptime: 20:17:07 up 4 days, 21:38, 2 users, load average: 0.01, 0.03, 0.00 User-Agent: Mutt/2.2.13 (2024-03-09) Received-SPF: pass client-ip=2a00:1098:5b::1; envelope-from=dg@treblig.org; helo=mx.treblig.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org * Peter Xu (peterx@redhat.com) wrote: > On Wed, Sep 02, 2026 at 07:15:39PM -0300, Fabiano Rosas wrote: > > Change the hmp_migrate_set_parameter command to use a keyval input > > visitor. > > > > Currently a string visitor is used and due to limitations of that > > particular visitor's implementation it's necessary to consult the QAPI > > type enum (MigrationParameter_lookup) and call each visit_type_* > > function individually. Which makes using a visitor pointless. > > > > Since there are other visitors implemented properly and generated code > > to iterate the QAPI object, prefer using one of those. The keyval > > input visitor is adequate because HMP provides basically one key and > > one value for each migrate_set_parameter command. > > > > To switch from string_input_visitor to keyval_input_visitor simply put > > the parameter name and value into a dict and invoke > > visit_type_MigrationParameters(). > > > > Note that it's not necessary to go through any of the keyval_* code > > because due to the nature of HMP, there's no parsing to do (no '=', no > > ',', etc). > > > > With this the migrate_set_parameters HMP commands will be > > automatically updated anytime a new migration parameter is added. > > > > The bad part: > > > > Some parameters accept a non-standard data format, I moved them to a > > "legacy" suffixed function in this patch as there's only 3 of them: > > > > - "max-bandwidth" and "avail-switchover-bandwidth" take MiB instead of B for > > a size parameter; > > Ah, I think it's only because I reused max-bandwidth unit there, but > didn't reuse the same unit for max-postcopy-bandwidth at least.. > > IIUC, HMP ABI isn't guaranteed anyway, so I wonder if we can still remove > these non-standard settings, maybe starting with some warning messages. Cc > Dave. Right; I'm fine with those changes; put a note at the top saying that it changes and a note in the changelog. Someone will have a test script somewhere that might depend on it (I know I did when I was debugging migration - and I never remembered what was MB or byte!) (I also thought there was some subtlety in the parameters for tls that I can't remember) > > - "cpr-exec-command" takes the strList type which needs to be built > > manually. If that changes behaviour please put an example before and after in the commit message. Dave > > Signed-off-by: Fabiano Rosas > > --- > > migration/migration-hmp-cmds.c | 203 +++++++++-------------------- > > tests/qtest/migration/misc-tests.c | 2 +- > > 2 files changed, 59 insertions(+), 146 deletions(-) > > > > diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c > > index ad68fa23aa4..220ac28b5e3 100644 > > --- a/migration/migration-hmp-cmds.c > > +++ b/migration/migration-hmp-cmds.c > > @@ -24,7 +24,9 @@ > > #include "qapi/error.h" > > #include "qapi/qapi-commands-migration.h" > > #include "qapi/qapi-visit-migration.h" > > +#include "qapi/qobject-input-visitor.h" > > #include "qobject/qdict.h" > > +#include "qobject/qstring.h" > > #include "qapi/string-input-visitor.h" > > #include "qapi/string-output-visitor.h" > > #include "qemu/cutils.h" > > @@ -589,59 +591,16 @@ end: > > hmp_handle_error(mon, err); > > } > > > > -void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > +static void hmp_migrate_set_parameter_legacy(Monitor *mon, const QDict *qdict) > > { > > const char *param = qdict_get_str(qdict, "parameter"); > > const char *valuestr = qdict_get_str(qdict, "value"); > > - Visitor *v = string_input_visitor_new(valuestr); > > MigrationParameters *p = g_new0(MigrationParameters, 1); > > uint64_t valuebw = 0; > > - uint64_t cache_size; > > Error *err = NULL; > > - int val, ret; > > + int ret; > > > > - val = qapi_enum_parse(&MigrationParameter_lookup, param, -1, &err); > > - if (val < 0) { > > - goto cleanup; > > - } > > - > > - switch (val) { > > - case MIGRATION_PARAMETER_THROTTLE_TRIGGER_THRESHOLD: > > - p->has_throttle_trigger_threshold = true; > > - visit_type_uint8(v, param, &p->throttle_trigger_threshold, &err); > > - break; > > - case MIGRATION_PARAMETER_CPU_THROTTLE_INITIAL: > > - p->has_cpu_throttle_initial = true; > > - visit_type_uint8(v, param, &p->cpu_throttle_initial, &err); > > - break; > > - case MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT: > > - p->has_cpu_throttle_increment = true; > > - visit_type_uint8(v, param, &p->cpu_throttle_increment, &err); > > - break; > > - case MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW: > > - p->has_cpu_throttle_tailslow = true; > > - visit_type_bool(v, param, &p->cpu_throttle_tailslow, &err); > > - break; > > - case MIGRATION_PARAMETER_MAX_CPU_THROTTLE: > > - p->has_max_cpu_throttle = true; > > - visit_type_uint8(v, param, &p->max_cpu_throttle, &err); > > - break; > > - case MIGRATION_PARAMETER_TLS_CREDS: > > - p->tls_creds = g_new0(StrOrNull, 1); > > - p->tls_creds->type = QTYPE_QSTRING; > > - visit_type_str(v, param, &p->tls_creds->u.s, &err); > > - break; > > - case MIGRATION_PARAMETER_TLS_HOSTNAME: > > - p->tls_hostname = g_new0(StrOrNull, 1); > > - p->tls_hostname->type = QTYPE_QSTRING; > > - visit_type_str(v, param, &p->tls_hostname->u.s, &err); > > - break; > > - case MIGRATION_PARAMETER_TLS_AUTHZ: > > - p->tls_authz = g_new0(StrOrNull, 1); > > - p->tls_authz->type = QTYPE_QSTRING; > > - visit_type_str(v, param, &p->tls_authz->u.s, &err); > > - break; > > - case MIGRATION_PARAMETER_MAX_BANDWIDTH: > > + if (g_str_equal(param, "max-bandwidth")) { > > p->has_max_bandwidth = true; > > /* > > * Can't use visit_type_size() here, because it > > @@ -651,109 +610,21 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > if (ret < 0 || valuebw > INT64_MAX > > || (size_t)valuebw != valuebw) { > > error_setg(&err, "Invalid size %s", valuestr); > > - break; > > + return; > > This may leak @err and @p? > > > } > > p->max_bandwidth = valuebw; > > - break; > > - case MIGRATION_PARAMETER_AVAIL_SWITCHOVER_BANDWIDTH: > > + > > + } else if (g_str_equal(param, "avail-switchover-bandwidth")) { > > p->has_avail_switchover_bandwidth = true; > > ret = qemu_strtosz_MiB(valuestr, NULL, &valuebw); > > if (ret < 0 || valuebw > INT64_MAX > > || (size_t)valuebw != valuebw) { > > error_setg(&err, "Invalid size %s", valuestr); > > - break; > > + return; > > Same. > > > } > > p->avail_switchover_bandwidth = valuebw; > > - break; > > - case MIGRATION_PARAMETER_DOWNTIME_LIMIT: > > - p->has_downtime_limit = true; > > - visit_type_size(v, param, &p->downtime_limit, &err); > > - break; > > - case MIGRATION_PARAMETER_X_CHECKPOINT_DELAY: > > - p->has_x_checkpoint_delay = true; > > - visit_type_uint32(v, param, &p->x_checkpoint_delay, &err); > > - break; > > - case MIGRATION_PARAMETER_MULTIFD_CHANNELS: > > - p->has_multifd_channels = true; > > - visit_type_uint8(v, param, &p->multifd_channels, &err); > > - break; > > - case MIGRATION_PARAMETER_MULTIFD_COMPRESSION: > > - p->has_multifd_compression = true; > > - visit_type_MultiFDCompression(v, param, &p->multifd_compression, > > - &err); > > - break; > > - case MIGRATION_PARAMETER_MULTIFD_ZLIB_LEVEL: > > - p->has_multifd_zlib_level = true; > > - visit_type_uint8(v, param, &p->multifd_zlib_level, &err); > > - break; > > - case MIGRATION_PARAMETER_MULTIFD_QATZIP_LEVEL: > > - p->has_multifd_qatzip_level = true; > > - visit_type_uint8(v, param, &p->multifd_qatzip_level, &err); > > - break; > > - case MIGRATION_PARAMETER_MULTIFD_ZSTD_LEVEL: > > - p->has_multifd_zstd_level = true; > > - visit_type_uint8(v, param, &p->multifd_zstd_level, &err); > > - break; > > - case MIGRATION_PARAMETER_ZERO_PAGE_DETECTION: > > - p->has_zero_page_detection = true; > > - visit_type_ZeroPageDetection(v, param, &p->zero_page_detection, &err); > > - break; > > - case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE: > > - p->has_xbzrle_cache_size = true; > > - if (!visit_type_size(v, param, &cache_size, &err)) { > > - break; > > - } > > - if (cache_size > INT64_MAX || (size_t)cache_size != cache_size) { > > - error_setg(&err, "Invalid size %s", valuestr); > > - break; > > - } > > - p->xbzrle_cache_size = cache_size; > > - break; > > - case MIGRATION_PARAMETER_MAX_POSTCOPY_BANDWIDTH: > > - p->has_max_postcopy_bandwidth = true; > > - visit_type_size(v, param, &p->max_postcopy_bandwidth, &err); > > - break; > > - case MIGRATION_PARAMETER_ANNOUNCE_INITIAL: > > - p->has_announce_initial = true; > > - visit_type_size(v, param, &p->announce_initial, &err); > > - break; > > - case MIGRATION_PARAMETER_ANNOUNCE_MAX: > > - p->has_announce_max = true; > > - visit_type_size(v, param, &p->announce_max, &err); > > - break; > > - case MIGRATION_PARAMETER_ANNOUNCE_ROUNDS: > > - p->has_announce_rounds = true; > > - visit_type_size(v, param, &p->announce_rounds, &err); > > - break; > > - case MIGRATION_PARAMETER_ANNOUNCE_STEP: > > - p->has_announce_step = true; > > - visit_type_size(v, param, &p->announce_step, &err); > > - break; > > - case MIGRATION_PARAMETER_BLOCK_BITMAP_MAPPING: > > - error_setg(&err, "The block-bitmap-mapping parameter can only be set " > > - "through QMP"); > > - break; > > - case MIGRATION_PARAMETER_X_VCPU_DIRTY_LIMIT_PERIOD: > > - p->has_x_vcpu_dirty_limit_period = true; > > - visit_type_size(v, param, &p->x_vcpu_dirty_limit_period, &err); > > - break; > > - case MIGRATION_PARAMETER_VCPU_DIRTY_LIMIT: > > - p->has_vcpu_dirty_limit = true; > > - visit_type_size(v, param, &p->vcpu_dirty_limit, &err); > > - break; > > - case MIGRATION_PARAMETER_MODE: > > - p->has_mode = true; > > - visit_type_MigMode(v, param, &p->mode, &err); > > - break; > > - case MIGRATION_PARAMETER_DIRECT_IO: > > - p->has_direct_io = true; > > - visit_type_bool(v, param, &p->direct_io, &err); > > - break; > > - case MIGRATION_PARAMETER_X_RDMA_CHUNK_SIZE: > > - p->has_x_rdma_chunk_size = true; > > - visit_type_size(v, param, &p->x_rdma_chunk_size, &err); > > - break; > > - case MIGRATION_PARAMETER_CPR_EXEC_COMMAND: { > > + > > + } else if (g_str_equal(param, "cpr-exec-command")) { > > /* > > * NOTE: g_autofree will only auto g_free() the strv array when > > * needed, it will not free the strings within the array. It's > > @@ -766,15 +637,14 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > > > if (!g_shell_parse_argv(valuestr, NULL, &strv, &gerr)) { > > error_setg(&err, "%s", gerr->message); > > - break; > > + return; > > Same. > > > } > > for (int i = 0; strv[i]; i++) { > > QAPI_LIST_APPEND(tail, strv[i]); > > } > > p->has_cpr_exec_command = true; > > - break; > > - } > > - default: > > + > > + } else { > > g_assert_not_reached(); > > } > > > > @@ -784,12 +654,55 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > > > qmp_migrate_set_parameters(p, &err); > > > > - cleanup: > > +cleanup: > > qapi_free_MigrationParameters(p); > > + hmp_handle_error(mon, err); > > +} > > + > > +static void hmp_migrate_set_parameter_qapi(Monitor *mon, const QDict *qdict) > > +{ > > + const char *param = qdict_get_str(qdict, "parameter"); > > + const char *valuestr = qdict_get_str(qdict, "value"); > > + g_autoptr(QDict) input = qdict_new(); > > + g_autoptr(MigrationParameters) p = NULL; > > + Visitor *v; > > + Error *err = NULL; > > + > > + /* the same as keyval_parse(), but here there's no need to parse */ > > + qdict_put_obj(input, param, QOBJECT(qstring_from_str(valuestr))); > > + > > + v = qobject_input_visitor_new_keyval(QOBJECT(input)); > > + if (visit_type_MigrationParameters(v, NULL, &p, &err)) { > > + qmp_migrate_set_parameters(p, &err); > > + } > > + > > visit_free(v); > > hmp_handle_error(mon, err); > > } > > > > +void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) > > +{ > > + const char *param = qdict_get_str(qdict, "parameter"); > > + > > + if (g_str_equal(param, "block-bitmap-mapping")) { > > + Error *err = NULL; > > + > > + error_setg(&err, "The %s parameter can only be set through QMP", param); > > + hmp_handle_error(mon, err); > > + return; > > + } > > + > > + /* these have non-standard setters */ > > + if (g_str_equal(param, "max-bandwidth") || > > + g_str_equal(param, "avail-switchover-bandwidth") || > > + g_str_equal(param, "cpr-exec-command")) { > > + > > + return hmp_migrate_set_parameter_legacy(mon, qdict); > > + } > > + > > + hmp_migrate_set_parameter_qapi(mon, qdict); > > +} > > + > > void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict) > > { > > Error *err = NULL; > > diff --git a/tests/qtest/migration/misc-tests.c b/tests/qtest/migration/misc-tests.c > > index 3554900b758..ba8183978b3 100644 > > --- a/tests/qtest/migration/misc-tests.c > > +++ b/tests/qtest/migration/misc-tests.c > > @@ -48,7 +48,7 @@ typedef struct HMPTestData { > > HMPTestData test_cases[] = { > > TEST("", "", "migrate_set_parameter: string expected"), > > TEST("foo", "", "migrate_set_parameter: string expected"), > > - TEST("foo", "on", "Error: invalid parameter value: foo"), > > + TEST("foo", "on", "Error: Parameter 'foo' is unexpected"), > > > > /* bool */ > > TEST("cpu-throttle-tailslow", "on", "on"), > > -- > > 2.53.0 > > > > -- > Peter Xu > -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux | Happy \ \ dave @ treblig.org | | In Hex / \ _________________________|_____ http://www.treblig.org |_______/