From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35312) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxToO-0005Zf-PJ for qemu-devel@nongnu.org; Mon, 10 Apr 2017 03:32:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxToL-0001Pq-Jw for qemu-devel@nongnu.org; Mon, 10 Apr 2017 03:32:32 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:3351 helo=dggrg03-dlp.huawei.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.71) (envelope-from ) id 1cxToK-0001P7-HD for qemu-devel@nongnu.org; Mon, 10 Apr 2017 03:32:29 -0400 References: <1487734936-43472-1-git-send-email-zhang.zhanghailiang@huawei.com> <1487734936-43472-8-git-send-email-zhang.zhanghailiang@huawei.com> <20170407170600.GD2623@work-vm> From: Hailiang Zhang Message-ID: <58EB34CF.90700@huawei.com> Date: Mon, 10 Apr 2017 15:31:27 +0800 MIME-Version: 1.0 In-Reply-To: <20170407170600.GD2623@work-vm> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 07/15] COLO: Load PVM's dirty pages into SVM's RAM cache temporarily List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: xuquan8@huawei.com, qemu-devel@nongnu.org, zhangchen.fnst@cn.fujitsu.com, lizhijian@cn.fujitsu.com, xiecl.fnst@cn.fujitsu.com, Juan Quintela On 2017/4/8 1:06, Dr. David Alan Gilbert wrote: > * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote: >> We should not load PVM's state directly into SVM, because there maybe some >> errors happen when SVM is receving data, which will break SVM. >> >> We need to ensure receving all data before load the state into SVM. We use >> an extra memory to cache these data (PVM's ram). The ram cache in secondary side >> is initially the same as SVM/PVM's memory. And in the process of checkpoint, >> we cache the dirty pages of PVM into this ram cache firstly, so this ram cache >> always the same as PVM's memory at every checkpoint, then we flush this cached ram >> to SVM after we receive all PVM's state. > You're probably going to find this interesting to merge with Juan's recent RAM block series. > Probably not too hard, but he's touching a lot of the same code and rearranging things. Yes, I'll update this series on top of his series, better to send next version after his series been merged. Thanks, Hailiang > Dave > > >> Cc: Juan Quintela >> Signed-off-by: zhanghailiang >> Signed-off-by: Li Zhijian >> Reviewed-by: Dr. David Alan Gilbert >> --- >> include/exec/ram_addr.h | 1 + >> include/migration/migration.h | 4 +++ >> migration/colo.c | 14 +++++++++ >> migration/ram.c | 73 ++++++++++++++++++++++++++++++++++++++++++- >> 4 files changed, 91 insertions(+), 1 deletion(-) >> >> diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h >> index 3e79466..44e1190 100644 >> --- a/include/exec/ram_addr.h >> +++ b/include/exec/ram_addr.h >> @@ -27,6 +27,7 @@ struct RAMBlock { >> struct rcu_head rcu; >> struct MemoryRegion *mr; >> uint8_t *host; >> + uint8_t *colo_cache; /* For colo, VM's ram cache */ >> ram_addr_t offset; >> ram_addr_t used_length; >> ram_addr_t max_length; >> diff --git a/include/migration/migration.h b/include/migration/migration.h >> index 1735d66..93c6148 100644 >> --- a/include/migration/migration.h >> +++ b/include/migration/migration.h >> @@ -379,4 +379,8 @@ int ram_save_queue_pages(MigrationState *ms, const char *rbname, >> PostcopyState postcopy_state_get(void); >> /* Set the state and return the old state */ >> PostcopyState postcopy_state_set(PostcopyState new_state); >> + >> +/* ram cache */ >> +int colo_init_ram_cache(void); >> +void colo_release_ram_cache(void); >> #endif >> diff --git a/migration/colo.c b/migration/colo.c >> index 1e3e975..edb7f00 100644 >> --- a/migration/colo.c >> +++ b/migration/colo.c >> @@ -551,6 +551,7 @@ void *colo_process_incoming_thread(void *opaque) >> uint64_t total_size; >> uint64_t value; >> Error *local_err = NULL; >> + int ret; >> >> qemu_sem_init(&mis->colo_incoming_sem, 0); >> >> @@ -572,6 +573,12 @@ void *colo_process_incoming_thread(void *opaque) >> */ >> qemu_file_set_blocking(mis->from_src_file, true); >> >> + ret = colo_init_ram_cache(); >> + if (ret < 0) { >> + error_report("Failed to initialize ram cache"); >> + goto out; >> + } >> + >> bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE); >> fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc)); >> object_unref(OBJECT(bioc)); >> @@ -705,11 +712,18 @@ out: >> if (fb) { >> qemu_fclose(fb); >> } >> + /* >> + * We can ensure BH is hold the global lock, and will join COLO >> + * incoming thread, so here it is not necessary to lock here again, >> + * Or there will be a deadlock error. >> + */ >> + colo_release_ram_cache(); >> >> /* Hope this not to be too long to loop here */ >> qemu_sem_wait(&mis->colo_incoming_sem); >> qemu_sem_destroy(&mis->colo_incoming_sem); >> /* Must be called after failover BH is completed */ >> + >> if (mis->to_src_file) { >> qemu_fclose(mis->to_src_file); >> } >> diff --git a/migration/ram.c b/migration/ram.c >> index f289fcd..b588990 100644 >> --- a/migration/ram.c >> +++ b/migration/ram.c >> @@ -219,6 +219,7 @@ static RAMBlock *last_sent_block; >> static ram_addr_t last_offset; >> static QemuMutex migration_bitmap_mutex; >> static uint64_t migration_dirty_pages; >> +static bool ram_cache_enable; >> static uint32_t last_version; >> static bool ram_bulk_stage; >> >> @@ -2227,6 +2228,20 @@ static inline void *host_from_ram_block_offset(RAMBlock *block, >> return block->host + offset; >> } >> >> +static inline void *colo_cache_from_block_offset(RAMBlock *block, >> + ram_addr_t offset) >> +{ >> + if (!offset_in_ramblock(block, offset)) { >> + return NULL; >> + } >> + if (!block->colo_cache) { >> + error_report("%s: colo_cache is NULL in block :%s", >> + __func__, block->idstr); >> + return NULL; >> + } >> + return block->colo_cache + offset; >> +} >> + >> /* >> * If a page (or a whole RDMA chunk) has been >> * determined to be zero, then zap it. >> @@ -2542,7 +2557,12 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) >> RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) { >> RAMBlock *block = ram_block_from_stream(f, flags); >> >> - host = host_from_ram_block_offset(block, addr); >> + /* After going into COLO, we should load the Page into colo_cache */ >> + if (ram_cache_enable) { >> + host = colo_cache_from_block_offset(block, addr); >> + } else { >> + host = host_from_ram_block_offset(block, addr); >> + } >> if (!host) { >> error_report("Illegal RAM offset " RAM_ADDR_FMT, addr); >> ret = -EINVAL; >> @@ -2637,6 +2657,57 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) >> return ret; >> } >> >> +/* >> + * colo cache: this is for secondary VM, we cache the whole >> + * memory of the secondary VM, it will be called after first migration. >> + */ >> +int colo_init_ram_cache(void) >> +{ >> + RAMBlock *block; >> + >> + rcu_read_lock(); >> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { >> + block->colo_cache = qemu_anon_ram_alloc(block->used_length, NULL); >> + if (!block->colo_cache) { >> + error_report("%s: Can't alloc memory for COLO cache of block %s," >> + "size 0x" RAM_ADDR_FMT, __func__, block->idstr, >> + block->used_length); >> + goto out_locked; >> + } >> + memcpy(block->colo_cache, block->host, block->used_length); >> + } >> + rcu_read_unlock(); >> + ram_cache_enable = true; >> + return 0; >> + >> +out_locked: >> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { >> + if (block->colo_cache) { >> + qemu_anon_ram_free(block->colo_cache, block->used_length); >> + block->colo_cache = NULL; >> + } >> + } >> + >> + rcu_read_unlock(); >> + return -errno; >> +} >> + >> +void colo_release_ram_cache(void) >> +{ >> + RAMBlock *block; >> + >> + ram_cache_enable = false; >> + >> + rcu_read_lock(); >> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { >> + if (block->colo_cache) { >> + qemu_anon_ram_free(block->colo_cache, block->used_length); >> + block->colo_cache = NULL; >> + } >> + } >> + rcu_read_unlock(); >> +} >> + >> static SaveVMHandlers savevm_ram_handlers = { >> .save_live_setup = ram_save_setup, >> .save_live_iterate = ram_save_iterate, >> -- >> 1.8.3.1 >> >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK > > . >