From patchwork Wed Feb 19 20:34:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej S. Szmigiero" X-Patchwork-Id: 13982924 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 lists.gnu.org (lists.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 818D4C021AA for ; Wed, 19 Feb 2025 20:41:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tkqov-0000ns-Qz; Wed, 19 Feb 2025 15:37:26 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tkqok-0000YC-Oc for qemu-devel@nongnu.org; Wed, 19 Feb 2025 15:37:20 -0500 Received: from vps-ovh.mhejs.net ([145.239.82.108]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tkqoi-0004sW-KY for qemu-devel@nongnu.org; Wed, 19 Feb 2025 15:37:14 -0500 Received: from MUA by vps-ovh.mhejs.net with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98) (envelope-from ) id 1tkqoU-00000007VWJ-416n; Wed, 19 Feb 2025 21:36:58 +0100 From: "Maciej S. Szmigiero" To: Peter Xu , Fabiano Rosas Cc: Alex Williamson , =?utf-8?q?C=C3=A9dric_Le_G?= =?utf-8?q?oater?= , Eric Blake , Markus Armbruster , =?utf-8?q?Daniel_P_=2E_Berrang=C3=A9?= , Avihai Horon , Joao Martins , qemu-devel@nongnu.org Subject: [PATCH v5 30/36] vfio/migration: Multifd device state transfer support - send side Date: Wed, 19 Feb 2025 21:34:12 +0100 Message-ID: <608c869621ffe1688e08af98a373c33376487d53.1739994627.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.48.1 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=145.239.82.108; envelope-from=mhej@vps-ovh.mhejs.net; helo=vps-ovh.mhejs.net X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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: 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 From: "Maciej S. Szmigiero" Implement the multifd device state transfer via additional per-device thread inside save_live_complete_precopy_thread handler. Switch between doing the data transfer in the new handler and doing it in the old save_state handler depending on the x-migration-multifd-transfer device property value. Signed-off-by: Maciej S. Szmigiero --- hw/vfio/migration-multifd.c | 139 ++++++++++++++++++++++++++++++++++ hw/vfio/migration-multifd.h | 5 ++ hw/vfio/migration.c | 26 +++++-- hw/vfio/trace-events | 2 + include/hw/vfio/vfio-common.h | 8 ++ 5 files changed, 174 insertions(+), 6 deletions(-) diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c index 7200f6f1c2a2..0cfa9d31732a 100644 --- a/hw/vfio/migration-multifd.c +++ b/hw/vfio/migration-multifd.c @@ -476,6 +476,145 @@ bool vfio_multifd_transfer_setup(VFIODevice *vbasedev, Error **errp) return true; } +void vfio_multifd_emit_dummy_eos(VFIODevice *vbasedev, QEMUFile *f) +{ + assert(vfio_multifd_transfer_enabled(vbasedev)); + + /* + * Emit dummy NOP data on the main migration channel since the actual + * device state transfer is done via multifd channels. + */ + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); +} + +static bool +vfio_save_complete_precopy_thread_config_state(VFIODevice *vbasedev, + char *idstr, + uint32_t instance_id, + uint32_t idx, + Error **errp) +{ + g_autoptr(QIOChannelBuffer) bioc = NULL; + g_autoptr(QEMUFile) f = NULL; + int ret; + g_autofree VFIODeviceStatePacket *packet = NULL; + size_t packet_len; + + bioc = qio_channel_buffer_new(0); + qio_channel_set_name(QIO_CHANNEL(bioc), "vfio-device-config-save"); + + f = qemu_file_new_output(QIO_CHANNEL(bioc)); + + if (vfio_save_device_config_state(f, vbasedev, errp)) { + return false; + } + + ret = qemu_fflush(f); + if (ret) { + error_setg(errp, "save config state flush failed: %d", ret); + return false; + } + + packet_len = sizeof(*packet) + bioc->usage; + packet = g_malloc0(packet_len); + packet->version = VFIO_DEVICE_STATE_PACKET_VER_CURRENT; + packet->idx = idx; + packet->flags = VFIO_DEVICE_STATE_CONFIG_STATE; + memcpy(&packet->data, bioc->data, bioc->usage); + + if (!multifd_queue_device_state(idstr, instance_id, + (char *)packet, packet_len)) { + error_setg(errp, "multifd config data queuing failed"); + return false; + } + + vfio_add_bytes_transferred(packet_len); + + return true; +} + +/* + * This thread is spawned by the migration core directly via + * .save_live_complete_precopy_thread SaveVMHandler. + * + * It exits after either: + * * completing saving the remaining device state and device config, OR: + * * encountering some error while doing the above, OR: + * * being forcefully aborted by the migration core by + * multifd_device_state_save_thread_should_exit() returning true. + */ +bool vfio_save_complete_precopy_thread(SaveLiveCompletePrecopyThreadData *d, + Error **errp) +{ + VFIODevice *vbasedev = d->handler_opaque; + VFIOMigration *migration = vbasedev->migration; + bool ret; + g_autofree VFIODeviceStatePacket *packet = NULL; + uint32_t idx; + + if (!vfio_multifd_transfer_enabled(vbasedev)) { + /* Nothing to do, vfio_save_complete_precopy() does the transfer. */ + return true; + } + + trace_vfio_save_complete_precopy_thread_start(vbasedev->name, + d->idstr, d->instance_id); + + /* We reach here with device state STOP or STOP_COPY only */ + if (vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY, + VFIO_DEVICE_STATE_STOP, errp)) { + ret = false; + goto ret_finish; + } + + packet = g_malloc0(sizeof(*packet) + migration->data_buffer_size); + packet->version = VFIO_DEVICE_STATE_PACKET_VER_CURRENT; + + for (idx = 0; ; idx++) { + ssize_t data_size; + size_t packet_size; + + if (multifd_device_state_save_thread_should_exit()) { + error_setg(errp, "operation cancelled"); + ret = false; + goto ret_finish; + } + + data_size = read(migration->data_fd, &packet->data, + migration->data_buffer_size); + if (data_size < 0) { + error_setg(errp, "reading state buffer %" PRIu32 " failed: %d", + idx, errno); + ret = false; + goto ret_finish; + } else if (data_size == 0) { + break; + } + + packet->idx = idx; + packet_size = sizeof(*packet) + data_size; + + if (!multifd_queue_device_state(d->idstr, d->instance_id, + (char *)packet, packet_size)) { + error_setg(errp, "multifd data queuing failed"); + ret = false; + goto ret_finish; + } + + vfio_add_bytes_transferred(packet_size); + } + + ret = vfio_save_complete_precopy_thread_config_state(vbasedev, + d->idstr, + d->instance_id, + idx, errp); + +ret_finish: + trace_vfio_save_complete_precopy_thread_end(vbasedev->name, ret); + + return ret; +} + int vfio_multifd_switchover_start(VFIODevice *vbasedev) { VFIOMigration *migration = vbasedev->migration; diff --git a/hw/vfio/migration-multifd.h b/hw/vfio/migration-multifd.h index 09cbb437d9d1..79780d7b5392 100644 --- a/hw/vfio/migration-multifd.h +++ b/hw/vfio/migration-multifd.h @@ -25,6 +25,11 @@ bool vfio_multifd_transfer_setup(VFIODevice *vbasedev, Error **errp); bool vfio_load_state_buffer(void *opaque, char *data, size_t data_size, Error **errp); +void vfio_multifd_emit_dummy_eos(VFIODevice *vbasedev, QEMUFile *f); + +bool vfio_save_complete_precopy_thread(SaveLiveCompletePrecopyThreadData *d, + Error **errp); + int vfio_multifd_switchover_start(VFIODevice *vbasedev); #endif diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index b962309f7c27..69dcf2dac2fa 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -120,10 +120,10 @@ static void vfio_migration_set_device_state(VFIODevice *vbasedev, vfio_migration_send_event(vbasedev); } -static int vfio_migration_set_state(VFIODevice *vbasedev, - enum vfio_device_mig_state new_state, - enum vfio_device_mig_state recover_state, - Error **errp) +int vfio_migration_set_state(VFIODevice *vbasedev, + enum vfio_device_mig_state new_state, + enum vfio_device_mig_state recover_state, + Error **errp) { VFIOMigration *migration = vbasedev->migration; uint64_t buf[DIV_ROUND_UP(sizeof(struct vfio_device_feature) + @@ -238,8 +238,7 @@ static int vfio_load_buffer(QEMUFile *f, VFIODevice *vbasedev, return ret; } -static int vfio_save_device_config_state(QEMUFile *f, void *opaque, - Error **errp) +int vfio_save_device_config_state(QEMUFile *f, void *opaque, Error **errp) { VFIODevice *vbasedev = opaque; int ret; @@ -453,6 +452,10 @@ static int vfio_save_setup(QEMUFile *f, void *opaque, Error **errp) uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE; int ret; + if (!vfio_multifd_transfer_setup(vbasedev, errp)) { + return -EINVAL; + } + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); vfio_query_stop_copy_size(vbasedev, &stop_copy_size); @@ -631,6 +634,11 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) int ret; Error *local_err = NULL; + if (vfio_multifd_transfer_enabled(vbasedev)) { + vfio_multifd_emit_dummy_eos(vbasedev, f); + return 0; + } + trace_vfio_save_complete_precopy_start(vbasedev->name); /* We reach here with device state STOP or STOP_COPY only */ @@ -662,6 +670,11 @@ static void vfio_save_state(QEMUFile *f, void *opaque) Error *local_err = NULL; int ret; + if (vfio_multifd_transfer_enabled(vbasedev)) { + vfio_multifd_emit_dummy_eos(vbasedev, f); + return; + } + ret = vfio_save_device_config_state(f, opaque, &local_err); if (ret) { error_prepend(&local_err, @@ -819,6 +832,7 @@ static const SaveVMHandlers savevm_vfio_handlers = { .is_active_iterate = vfio_is_active_iterate, .save_live_iterate = vfio_save_iterate, .save_live_complete_precopy = vfio_save_complete_precopy, + .save_live_complete_precopy_thread = vfio_save_complete_precopy_thread, .save_state = vfio_save_state, .load_setup = vfio_load_setup, .load_cleanup = vfio_load_cleanup, diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 418b378ebd29..039979bdd98f 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -168,6 +168,8 @@ vfio_save_block_precopy_empty_hit(const char *name) " (%s)" vfio_save_cleanup(const char *name) " (%s)" vfio_save_complete_precopy(const char *name, int ret) " (%s) ret %d" vfio_save_complete_precopy_start(const char *name) " (%s)" +vfio_save_complete_precopy_thread_start(const char *name, const char *idstr, uint32_t instance_id) " (%s) idstr %s instance %"PRIu32 +vfio_save_complete_precopy_thread_end(const char *name, int ret) " (%s) ret %d" vfio_save_device_config_state(const char *name) " (%s)" vfio_save_iterate(const char *name, uint64_t precopy_init_size, uint64_t precopy_dirty_size) " (%s) precopy initial size %"PRIu64" precopy dirty size %"PRIu64 vfio_save_iterate_start(const char *name) " (%s)" diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index ce2bdea8a2c2..ba851917f9fc 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -298,6 +298,14 @@ void vfio_add_bytes_transferred(unsigned long val); bool vfio_device_state_is_running(VFIODevice *vbasedev); bool vfio_device_state_is_precopy(VFIODevice *vbasedev); +#ifdef CONFIG_LINUX +int vfio_migration_set_state(VFIODevice *vbasedev, + enum vfio_device_mig_state new_state, + enum vfio_device_mig_state recover_state, + Error **errp); +#endif + +int vfio_save_device_config_state(QEMUFile *f, void *opaque, Error **errp); int vfio_load_device_config_state(QEMUFile *f, void *opaque); #ifdef CONFIG_LINUX