From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46768) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1qqX-000755-NY for qemu-devel@nongnu.org; Thu, 26 Nov 2015 02:20:03 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a1qqS-0006Hv-9f for qemu-devel@nongnu.org; Thu, 26 Nov 2015 02:20:01 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:35374) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a1qqR-0006H3-0R for qemu-devel@nongnu.org; Thu, 26 Nov 2015 02:19:56 -0500 References: <1448357149-17572-1-git-send-email-zhang.zhanghailiang@huawei.com> <1448357149-17572-11-git-send-email-zhang.zhanghailiang@huawei.com> <20151124190048.GK2490@work-vm> From: Hailiang Zhang Message-ID: <5656B0C9.6080904@huawei.com> Date: Thu, 26 Nov 2015 15:12:09 +0800 MIME-Version: 1.0 In-Reply-To: <20151124190048.GK2490@work-vm> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH COLO-Frame v11 10/39] COLO: Implement colo checkpoint protocol List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: lizhijian@cn.fujitsu.com, quintela@redhat.com, yunhong.jiang@intel.com, eddie.dong@intel.com, peter.huangpeng@huawei.com, qemu-devel@nongnu.org, arei.gonglei@huawei.com, stefanha@redhat.com, amit.shah@redhat.com, hongyang.yang@easystack.cn On 2015/11/25 3:00, Dr. David Alan Gilbert wrote: > * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote: >> We need communications protocol of user-defined to control the checkpoint >> process. >> >> The new checkpoint request is started by Primary VM, and the interactive process >> like below: >> Checkpoint synchronizing points, >> >> Primary Secondary >> initial work >> 'checkpoint-ready' <------------------------------ @ >> >> 'checkpoint-request' @ -----------------------------> >> Suspend (Only in hybrid mode) >> 'checkpoint-reply' <------------------------------ @ >> Suspend&Save state >> 'vmstate-send' @ -----------------------------> >> Send state Receive state >> 'vmstate-received' <------------------------------ @ >> Release packets Load state >> 'vmstate-load' <------------------------------ @ >> Resume Resume (Only in hybrid mode) >> >> Start Comparing (Only in hybrid mode) >> NOTE: >> 1) '@' who sends the message >> 2) Every sync-point is synchronized by two sides with only >> one handshake(single direction) for low-latency. >> If more strict synchronization is required, a opposite direction >> sync-point should be added. >> 3) Since sync-points are single direction, the remote side may >> go forward a lot when this side just receives the sync-point. >> 4) For now, we only support 'periodic' checkpoint, for which >> the Secondary VM is not running, later we will support 'hybrid' mode. >> >> Signed-off-by: zhanghailiang >> Signed-off-by: Li Zhijian >> Signed-off-by: Gonglei >> Cc: Eric Blake >> --- >> v11: >> - Add missing 'checkpoint-ready' communication in comment. >> - Use parameter to return 'value' for colo_ctl_get() (Dave's suggestion) >> - Fix trace for colo_ctl_get() to trace command and value both >> v10: >> - Rename enum COLOCmd to COLOCommand (Eric's suggestion). >> - Remove unused 'ram-steal' >> --- >> migration/colo.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- >> qapi-schema.json | 27 ++++++++ >> trace-events | 2 + >> 3 files changed, 225 insertions(+), 2 deletions(-) >> >> diff --git a/migration/colo.c b/migration/colo.c >> index 0ab9618..c045d61 100644 >> --- a/migration/colo.c >> +++ b/migration/colo.c >> @@ -10,10 +10,12 @@ >> * later. See the COPYING file in the top-level directory. >> */ >> >> +#include >> #include "sysemu/sysemu.h" >> #include "migration/colo.h" >> #include "trace.h" >> #include "qemu/error-report.h" >> +#include "qemu/sockets.h" >> >> bool colo_supported(void) >> { >> @@ -34,9 +36,107 @@ bool migration_incoming_in_colo_state(void) >> return mis && (mis->state == MIGRATION_STATUS_COLO); >> } >> >> +/* colo checkpoint control helper */ >> +static int colo_ctl_put(QEMUFile *f, uint32_t cmd, uint64_t value) >> +{ >> + int ret = 0; >> + >> + qemu_put_be32(f, cmd); >> + qemu_put_be64(f, value); >> + qemu_fflush(f); >> + >> + ret = qemu_file_get_error(f); >> + trace_colo_ctl_put(COLOCommand_lookup[cmd], value); >> + >> + return ret; >> +} >> + >> +static int colo_ctl_get_cmd(QEMUFile *f, uint32_t *cmd) >> +{ >> + int ret = 0; >> + >> + *cmd = qemu_get_be32(f); >> + ret = qemu_file_get_error(f); >> + if (ret < 0) { >> + return ret; >> + } >> + if (*cmd >= COLO_COMMAND_MAX) { >> + error_report("Invalid colo command, got cmd:%d", *cmd); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> + >> +static int colo_ctl_get(QEMUFile *f, uint32_t require, uint64_t *value) >> +{ >> + int ret; >> + uint32_t cmd; >> + >> + ret = colo_ctl_get_cmd(f, &cmd); >> + if (ret < 0) { >> + return ret; >> + } >> + if (cmd != require) { >> + error_report("Unexpect colo command, expect:%d, but got cmd:%d", >> + require, cmd); > > I think you need to use PRIu32 rather than %d since they are uint32_t > (I doubt it will break on anything, but it's correct). > >> + return -EINVAL; >> + } >> + >> + *value = qemu_get_be64(f); >> + trace_colo_ctl_get(COLOCommand_lookup[cmd], *value); >> + ret = qemu_file_get_error(f); >> + >> + return ret; >> +} >> + >> +static int colo_do_checkpoint_transaction(MigrationState *s) >> +{ >> + int ret; >> + uint64_t value; >> + >> + ret = colo_ctl_put(s->to_dst_file, COLO_COMMAND_CHECKPOINT_REQUEST, 0); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + ret = colo_ctl_get(s->rp_state.from_dst_file, >> + COLO_COMMAND_CHECKPOINT_REPLY, &value); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + /* TODO: suspend and save vm state to colo buffer */ >> + >> + ret = colo_ctl_put(s->to_dst_file, COLO_COMMAND_VMSTATE_SEND, 0); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + /* TODO: send vmstate to Secondary */ >> + >> + ret = colo_ctl_get(s->rp_state.from_dst_file, >> + COLO_COMMAND_VMSTATE_RECEIVED, &value); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + ret = colo_ctl_get(s->rp_state.from_dst_file, >> + COLO_COMMAND_VMSTATE_LOADED, &value); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + /* TODO: resume Primary */ >> + >> +out: >> + return ret; >> +} >> + >> static void colo_process_checkpoint(MigrationState *s) >> { >> int ret = 0; >> + uint64_t value; >> >> s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file); >> if (!s->rp_state.from_dst_file) { >> @@ -45,12 +145,28 @@ static void colo_process_checkpoint(MigrationState *s) >> goto out; >> } >> >> + /* >> + * Wait for Secondary finish loading vm states and enter COLO >> + * restore. >> + */ >> + ret = colo_ctl_get(s->rp_state.from_dst_file, >> + COLO_COMMAND_CHECKPOINT_READY, &value); >> + if (ret < 0) { >> + goto out; >> + } >> + >> qemu_mutex_lock_iothread(); >> vm_start(); >> qemu_mutex_unlock_iothread(); >> trace_colo_vm_state_change("stop", "run"); >> >> - /*TODO: COLO checkpoint savevm loop*/ >> + while (s->state == MIGRATION_STATUS_COLO) { >> + /* start a colo checkpoint */ >> + ret = colo_do_checkpoint_transaction(s); >> + if (ret < 0) { >> + goto out; >> + } >> + } >> >> out: >> if (ret < 0) { >> @@ -73,10 +189,46 @@ void migrate_start_colo_process(MigrationState *s) >> qemu_mutex_lock_iothread(); >> } >> >> +/* >> + * return: >> + * 0: start a checkpoint >> + * -1: some error happened, exit colo restore >> + */ >> +static int colo_wait_handle_cmd(QEMUFile *f, int *checkpoint_request) >> +{ >> + int ret; >> + uint32_t cmd; >> + uint64_t value; >> + >> + ret = colo_ctl_get_cmd(f, &cmd); >> + if (ret < 0) { >> + /* do failover ? */ >> + return ret; >> + } >> + /* Fix me: this value should be 0, which is not so good, >> + * should be used for checking ? >> + */ > > You could use something simple like an incrementing value, if you just > wanted to make it a little more robust against problems. > Hmm, this a good choice, but we have to hold a variable to record the increasing value. Checking the length of the corresponding commands' string seems better. :) >> + value = qemu_get_be64(f); >> + if (value != 0) { >> + error_report("Got unexpected value %" PRIu64 " for '%s' command", >> + value, COLOCommand_lookup[cmd]); >> + return -EINVAL; >> + } >> + >> + switch (cmd) { >> + case COLO_COMMAND_CHECKPOINT_REQUEST: >> + *checkpoint_request = 1; >> + return 0; >> + default: >> + return -EINVAL; >> + } >> +} >> + >> void *colo_process_incoming_thread(void *opaque) >> { >> MigrationIncomingState *mis = opaque; >> int ret = 0; >> + uint64_t value; >> >> migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, >> MIGRATION_STATUS_COLO); >> @@ -93,7 +245,49 @@ void *colo_process_incoming_thread(void *opaque) >> */ >> qemu_set_block(qemu_get_fd(mis->from_src_file)); >> >> - /* TODO: COLO checkpoint restore loop */ >> + >> + ret = colo_ctl_put(mis->to_src_file, COLO_COMMAND_CHECKPOINT_READY, 0); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + while (mis->state == MIGRATION_STATUS_COLO) { >> + int request = 0; >> + int ret = colo_wait_handle_cmd(mis->from_src_file, &request); >> + >> + if (ret < 0) { >> + break; >> + } else { >> + if (!request) { >> + continue; >> + } >> + } >> + /* FIXME: This is unnecessary for periodic checkpoint mode */ >> + ret = colo_ctl_put(mis->to_src_file, COLO_COMMAND_CHECKPOINT_REPLY, 0); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + ret = colo_ctl_get(mis->from_src_file, COLO_COMMAND_VMSTATE_SEND, >> + &value); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + /* TODO: read migration data into colo buffer */ >> + >> + ret = colo_ctl_put(mis->to_src_file, COLO_COMMAND_VMSTATE_RECEIVED, 0); >> + if (ret < 0) { >> + goto out; >> + } >> + >> + /* TODO: load vm state */ >> + >> + ret = colo_ctl_put(mis->to_src_file, COLO_COMMAND_VMSTATE_LOADED, 0); >> + if (ret < 0) { >> + goto out; >> + } >> + } >> >> out: >> if (ret < 0) { >> diff --git a/qapi-schema.json b/qapi-schema.json >> index c2f3b63..48a87af 100644 >> --- a/qapi-schema.json >> +++ b/qapi-schema.json >> @@ -722,6 +722,33 @@ >> { 'command': 'migrate-start-postcopy' } >> >> ## >> +# @COLOCommand >> +# >> +# The commands for COLO fault tolerance >> +# >> +# @invalid: unknown command >> +# >> +# @checkpoint-ready: SVM is ready for checkpointing >> +# >> +# @checkpoint-request: PVM tells SVM to prepare for new checkpointing >> +# >> +# @checkpoint-reply: SVM gets PVM's checkpoint request >> +# >> +# @vmstate-send: VM's state will be sent by PVM. >> +# >> +# @vmstate-size: The total size of VMstate. >> +# >> +# @vmstate-received: VM's state has been received by SVM >> +# >> +# @vmstate-loaded: VM's state has been loaded by SVM >> +# >> +# Since: 2.6 >> +## >> +{ 'enum': 'COLOCommand', >> + 'data': [ 'invalid', 'checkpoint-ready', 'checkpoint-request', >> + 'checkpoint-reply', 'vmstate-send', 'vmstate-size', >> + 'vmstate-received', 'vmstate-loaded' ] } >> + >> # @MouseInfo: >> # >> # Information about a mouse device. >> diff --git a/trace-events b/trace-events >> index c98d473..f8a0959 100644 >> --- a/trace-events >> +++ b/trace-events >> @@ -1579,6 +1579,8 @@ postcopy_ram_incoming_cleanup_join(void) "" >> >> # migration/colo.c >> colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'" >> +colo_ctl_put(const char *msg, uint64_t value) "Send '%s' cmd, value: %" PRIu64"" >> +colo_ctl_get(const char *msg, uint64_t value) "Receive '%s' cmd, value: %" PRIu64"" > > I don't think you need the "" at the end of the line > OK, will fix in next version. Thanks, Hailiang > Dave > >> >> # kvm-all.c >> kvm_ioctl(int type, void *arg) "type 0x%x, arg %p" >> -- >> 1.8.3.1 >> >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > > . >