From patchwork Tue Aug 27 17:54:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej S. Szmigiero" X-Patchwork-Id: 13779947 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 3D453C5472F for ; Tue, 27 Aug 2024 17:58:07 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sj0RP-0003YW-RE; Tue, 27 Aug 2024 13:57:17 -0400 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 1sj0Qj-00006n-0W for qemu-devel@nongnu.org; Tue, 27 Aug 2024 13:56:33 -0400 Received: from vps-vb.mhejs.net ([37.28.154.113]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sj0Qg-0001eo-PZ for qemu-devel@nongnu.org; Tue, 27 Aug 2024 13:56:32 -0400 Received: from MUA by vps-vb.mhejs.net with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sj0QY-0002Qh-Ai; Tue, 27 Aug 2024 19:56:22 +0200 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 v2 17/17] vfio/migration: Multifd device state transfer support - send side Date: Tue, 27 Aug 2024 19:54:36 +0200 Message-ID: <1429fc59079d99ca035b31303892d807868dc6c0.1724701542.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=37.28.154.113; envelope-from=mail@maciej.szmigiero.name; helo=vps-vb.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, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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.c | 169 ++++++++++++++++++++++++++++++++++ hw/vfio/trace-events | 2 + include/hw/vfio/vfio-common.h | 1 + 3 files changed, 172 insertions(+) diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c index 57c1542528dc..67996aa2df8b 100644 --- a/hw/vfio/migration.c +++ b/hw/vfio/migration.c @@ -655,6 +655,16 @@ static int vfio_save_setup(QEMUFile *f, void *opaque, Error **errp) uint64_t stop_copy_size = VFIO_MIG_DEFAULT_DATA_BUFFER_SIZE; int ret; + /* Make a copy of this setting at the start in case it is changed mid-migration */ + migration->multifd_transfer = vbasedev->migration_multifd_transfer; + + if (migration->multifd_transfer && !migration_has_device_state_support()) { + error_setg(errp, + "%s: Multifd device transfer requested but unsupported in the current config", + vbasedev->name); + return -EINVAL; + } + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE); vfio_query_stop_copy_size(vbasedev, &stop_copy_size); @@ -835,10 +845,20 @@ static int vfio_save_iterate(QEMUFile *f, void *opaque) static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) { VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; ssize_t data_size; int ret; Error *local_err = NULL; + if (migration->multifd_transfer) { + /* + * Emit dummy NOP data, vfio_save_complete_precopy_thread() + * does the actual transfer. + */ + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + return 0; + } + trace_vfio_save_complete_precopy_started(vbasedev->name); /* We reach here with device state STOP or STOP_COPY only */ @@ -864,12 +884,159 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque) return ret; } +static int vfio_save_complete_precopy_async_thread_config_state(VFIODevice *vbasedev, + char *idstr, + uint32_t instance_id, + uint32_t idx) +{ + g_autoptr(QIOChannelBuffer) bioc = NULL; + 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)); + + ret = vfio_save_device_config_state(f, vbasedev, NULL); + if (ret) { + return ret; + } + + ret = qemu_fflush(f); + if (ret) { + goto ret_close_file; + } + + packet_len = sizeof(*packet) + bioc->usage; + packet = g_malloc0(packet_len); + 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)) { + ret = -1; + } + + bytes_transferred += packet_len; + +ret_close_file: + g_clear_pointer(&f, qemu_fclose); + return ret; +} + +static int vfio_save_complete_precopy_thread(char *idstr, + uint32_t instance_id, + bool *abort_flag, + void *opaque) +{ + VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; + int ret; + g_autofree VFIODeviceStatePacket *packet = NULL; + uint32_t idx; + + if (!migration->multifd_transfer) { + /* Nothing to do, vfio_save_complete_precopy() does the transfer. */ + return 0; + } + + trace_vfio_save_complete_precopy_thread_started(vbasedev->name, + idstr, instance_id); + + /* We reach here with device state STOP or STOP_COPY only */ + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_STOP_COPY, + VFIO_DEVICE_STATE_STOP, NULL); + if (ret) { + goto ret_finish; + } + + packet = g_malloc0(sizeof(*packet) + migration->data_buffer_size); + + for (idx = 0; ; idx++) { + ssize_t data_size; + size_t packet_size; + + if (qatomic_read(abort_flag)) { + ret = -ECANCELED; + goto ret_finish; + } + + data_size = read(migration->data_fd, &packet->data, + migration->data_buffer_size); + if (data_size < 0) { + if (errno != ENOMSG) { + ret = -errno; + goto ret_finish; + } + + /* + * Pre-copy emptied all the device state for now. For more information, + * please refer to the Linux kernel VFIO uAPI. + */ + data_size = 0; + } + + if (data_size == 0) + break; + + packet->idx = idx; + packet_size = sizeof(*packet) + data_size; + + if (!multifd_queue_device_state(idstr, instance_id, + (char *)packet, packet_size)) { + ret = -1; + goto ret_finish; + } + + bytes_transferred += packet_size; + } + + ret = vfio_save_complete_precopy_async_thread_config_state(vbasedev, idstr, + instance_id, + idx); + +ret_finish: + trace_vfio_save_complete_precopy_thread_finished(vbasedev->name, ret); + + return ret; +} + +static int vfio_save_complete_precopy_begin(QEMUFile *f, + char *idstr, uint32_t instance_id, + void *opaque) +{ + VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; + + if (!migration->multifd_transfer) { + /* Emit dummy NOP data */ + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + return 0; + } + + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_DATA_STATE_COMPLETE); + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + + return qemu_fflush(f); +} + static void vfio_save_state(QEMUFile *f, void *opaque) { VFIODevice *vbasedev = opaque; + VFIOMigration *migration = vbasedev->migration; Error *local_err = NULL; int ret; + if (migration->multifd_transfer) { + /* Emit dummy NOP data */ + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE); + return; + } + ret = vfio_save_device_config_state(f, opaque, &local_err); if (ret) { error_prepend(&local_err, @@ -1119,7 +1286,9 @@ static const SaveVMHandlers savevm_vfio_handlers = { .state_pending_exact = vfio_state_pending_exact, .is_active_iterate = vfio_is_active_iterate, .save_live_iterate = vfio_save_iterate, + .save_live_complete_precopy_begin = vfio_save_complete_precopy_begin, .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 9d2519a28a7e..b1d9c9d5f2e1 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -167,6 +167,8 @@ vfio_save_block(const char *name, int data_size) " (%s) data_size %d" vfio_save_cleanup(const char *name) " (%s)" vfio_save_complete_precopy(const char *name, int ret) " (%s) ret %d" vfio_save_complete_precopy_started(const char *name) " (%s)" +vfio_save_complete_precopy_thread_started(const char *name, const char *idstr, uint32_t instance_id) " (%s) idstr %s instance %"PRIu32 +vfio_save_complete_precopy_thread_finished(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 0x%"PRIx64" precopy dirty size 0x%"PRIx64 vfio_save_iterate_started(const char *name) " (%s)" diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h index fe05acb9a5d1..4578a0ca6a5c 100644 --- a/include/hw/vfio/vfio-common.h +++ b/include/hw/vfio/vfio-common.h @@ -72,6 +72,7 @@ typedef struct VFIOMigration { uint64_t mig_flags; uint64_t precopy_init_size; uint64_t precopy_dirty_size; + bool multifd_transfer; bool initial_data_sent; bool save_iterate_run;