diff options
| -rw-r--r-- | drivers/hv/hv_balloon.c | 408 |
1 files changed, 387 insertions, 21 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 4743db9e5f34..2cf7d4e964bd 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -412,6 +412,27 @@ struct dm_info_msg { * End protocol definitions. */ +/* + * State to manage hot adding memory into the guest. + * The range start_pfn : end_pfn specifies the range + * that the host has asked us to hot add. The range + * start_pfn : ha_end_pfn specifies the range that we have + * currently hot added. We hot add in multiples of 128M + * chunks; it is possible that we may not be able to bring + * online all the pages in the region. The range + * covered_start_pfn : covered_end_pfn defines the pages that can + * be brough online. + */ + +struct hv_hotadd_state { + struct list_head list; + unsigned long start_pfn; + unsigned long covered_start_pfn; + unsigned long covered_end_pfn; + unsigned long ha_end_pfn; + unsigned long end_pfn; +}; + struct balloon_state { __u32 num_pages; struct work_struct wrk; @@ -419,16 +440,17 @@ struct balloon_state { struct hot_add_wrk { union dm_mem_page_range ha_page_range; + union dm_mem_page_range ha_region_range; struct work_struct wrk; }; -static bool hot_add; +static bool hot_add = true; static bool do_hot_add; /* * Delay reporting memory pressure by * the specified number of seconds. */ -static uint pressure_report_delay = 30; +static uint pressure_report_delay = 45; module_param(hot_add, bool, (S_IRUGO | S_IWUSR)); MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add"); @@ -456,6 +478,7 @@ enum hv_dm_state { static __u8 recv_buffer[PAGE_SIZE]; static __u8 *send_buffer; #define PAGES_IN_2M 512 +#define HA_CHUNK (32 * 1024) struct hv_dynmem_device { struct hv_device *dev; @@ -479,6 +502,17 @@ struct hv_dynmem_device { struct hot_add_wrk ha_wrk; /* + * This state tracks if the host has specified a hot-add + * region. + */ + bool host_specified_ha_region; + + /* + * State to synchronize hot-add. + */ + struct completion ol_waitevent; + bool ha_waiting; + /* * This thread handles hot-add * requests from the host as well as notifying * the host with regards to memory pressure in @@ -487,6 +521,11 @@ struct hv_dynmem_device { struct task_struct *thread; /* + * A list of hot-add regions. + */ + struct list_head ha_region_list; + + /* * We start with the highest version we can support * and downgrade based on the host; we save here the * next version to try. @@ -496,35 +535,329 @@ struct hv_dynmem_device { static struct hv_dynmem_device dm_device; -static void hot_add_req(struct work_struct *dummy) +#ifdef CONFIG_MEMORY_HOTPLUG + +void hv_bring_pgs_online(unsigned long start_pfn, unsigned long size) { + int i; - struct dm_hot_add_response resp; + for (i = 0; i < size; i++) { + struct page *pg; + pg = pfn_to_page(start_pfn + i); + __online_page_set_limits(pg); + __online_page_increment_counters(pg); + __online_page_free(pg); + } +} + +static void hv_mem_hot_add(unsigned long start, unsigned long size, + unsigned long pfn_count, + struct hv_hotadd_state *has) +{ + int ret = 0; + int i, nid, t; + unsigned long start_pfn; + unsigned long processed_pfn; + unsigned long total_pfn = pfn_count; + + for (i = 0; i < (size/HA_CHUNK); i++) { + start_pfn = start + (i * HA_CHUNK); + has->ha_end_pfn += HA_CHUNK; + + if (total_pfn > HA_CHUNK) { + processed_pfn = HA_CHUNK; + total_pfn -= HA_CHUNK; + } else { + processed_pfn = total_pfn; + total_pfn = 0; + } + + has->covered_end_pfn += processed_pfn; - if (do_hot_add) { + init_completion(&dm_device.ol_waitevent); + dm_device.ha_waiting = true; - pr_info("Memory hot add not supported\n"); + nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn)); + ret = add_memory(nid, PFN_PHYS((start_pfn)), + (HA_CHUNK << PAGE_SHIFT)); + + if (ret) { + pr_info("hot_add memory failed error is %d\n", ret); + has->ha_end_pfn -= HA_CHUNK; + has->covered_end_pfn -= processed_pfn; + break; + } /* - * Currently we do not support hot add. - * Just fail the request. + * Wait for the memory block to be onlined. */ + t = wait_for_completion_timeout(&dm_device.ol_waitevent, 5*HZ); + if (t == 0) { + pr_info("hot_add memory timedout\n"); + has->ha_end_pfn -= HA_CHUNK; + has->covered_end_pfn -= processed_pfn; + break; + } + } + return; +} + +static void hv_online_page(struct page *pg) +{ + struct list_head *cur; + struct hv_hotadd_state *has; + unsigned long cur_start_pgp; + unsigned long cur_end_pgp; + + if (dm_device.ha_waiting) { + dm_device.ha_waiting = false; + complete(&dm_device.ol_waitevent); + } + + list_for_each(cur, &dm_device.ha_region_list) { + has = list_entry(cur, struct hv_hotadd_state, list); + cur_start_pgp = (unsigned long) + pfn_to_page(has->covered_start_pfn); + cur_end_pgp = (unsigned long)pfn_to_page(has->covered_end_pfn); + + if (((unsigned long)pg >= cur_start_pgp) && + ((unsigned long)pg < cur_end_pgp)) { + /* + * This frame is currently backed; online the + * page. + */ + __online_page_set_limits(pg); + __online_page_increment_counters(pg); + __online_page_free(pg); + has->covered_start_pfn++; + } + } +} + +static bool pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt) +{ + struct list_head *cur; + struct hv_hotadd_state *has; + unsigned long residual, new_inc; + + if (list_empty(&dm_device.ha_region_list)) + return false; + + list_for_each(cur, &dm_device.ha_region_list) { + has = list_entry(cur, struct hv_hotadd_state, list); + + /* + * If the pfn range we are dealing with is not in the current + * "hot add block", move on. + */ + if ((start_pfn >= has->end_pfn)) + continue; + /* + * If the current hot add-request extends beyond + * our current limit; extend it. + */ + if ((start_pfn + pfn_cnt) > has->end_pfn) { + residual = (start_pfn + pfn_cnt - has->end_pfn); + /* + * Extend the region by multiples of HA_CHUNK. + */ + new_inc = (residual / HA_CHUNK) * HA_CHUNK; + if (residual % HA_CHUNK) + new_inc += HA_CHUNK; + + has->end_pfn += new_inc; + } + + /* + * If the current start pfn is not where the covered_end + * is, update it. + */ + + if (has->covered_end_pfn != start_pfn) { + has->covered_end_pfn = start_pfn; + has->covered_start_pfn = start_pfn; + } + return true; + + } + + return false; +} + +static unsigned long handle_pg_range(unsigned long pg_start, + unsigned long pg_count) +{ + unsigned long start_pfn = pg_start; + unsigned long pfn_cnt = pg_count; + unsigned long size; + struct list_head *cur; + struct hv_hotadd_state *has; + unsigned long pgs_ol = 0; + unsigned long old_covered_state; + + if (list_empty(&dm_device.ha_region_list)) + return 0; + + list_for_each(cur, &dm_device.ha_region_list) { + has = list_entry(cur, struct hv_hotadd_state, list); + + /* + * If the pfn range we are dealing with is not in the current + * "hot add block", move on. + */ + if ((start_pfn >= has->end_pfn)) + continue; + + old_covered_state = has->covered_end_pfn; + + if (start_pfn < has->ha_end_pfn) { + /* + * This is the case where we are backing pages + * in an already hot added region. Bring + * these pages online first. + */ + pgs_ol = has->ha_end_pfn - start_pfn; + if (pgs_ol > pfn_cnt) + pgs_ol = pfn_cnt; + hv_bring_pgs_online(start_pfn, pgs_ol); + has->covered_end_pfn += pgs_ol; + has->covered_start_pfn += pgs_ol; + pfn_cnt -= pgs_ol; + } + + if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) { + /* + * We have some residual hot add range + * that needs to be hot added; hot add + * it now. Hot add a multiple of + * of HA_CHUNK that fully covers the pages + * we have. + */ + size = (has->end_pfn - has->ha_end_pfn); + if (pfn_cnt <= size) { + size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK); + if (pfn_cnt % HA_CHUNK) + size += HA_CHUNK; + } else { + pfn_cnt = size; + } + hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has); + } + /* + * If we managed to online any pages that were given to us, + * we declare success. + */ + return has->covered_end_pfn - old_covered_state; + + } + + return 0; +} + +static unsigned long process_hot_add(unsigned long pg_start, + unsigned long pfn_cnt, + unsigned long rg_start, + unsigned long rg_size) +{ + struct hv_hotadd_state *ha_region = NULL; + + if (pfn_cnt == 0) + return 0; + + if (!dm_device.host_specified_ha_region) + if (pfn_covered(pg_start, pfn_cnt)) + goto do_pg_range; + + /* + * If the host has specified a hot-add range; deal with it first. + */ + + if ((rg_size != 0) && (!dm_device.host_specified_ha_region)) { + ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL); + if (!ha_region) + return 0; + + INIT_LIST_HEAD(&ha_region->list); + + list_add_tail(&ha_region->list, &dm_device.ha_region_list); + ha_region->start_pfn = rg_start; + ha_region->ha_end_pfn = rg_start; + ha_region->covered_start_pfn = pg_start; + ha_region->covered_end_pfn = pg_start; + ha_region->end_pfn = rg_start + rg_size; + } + +do_pg_range: + /* + * Process the page range specified; bringing them + * online if possible. + */ + return handle_pg_range(pg_start, pfn_cnt); +} + +#endif + +static void hot_add_req(struct work_struct *dummy) +{ + struct dm_hot_add_response resp; +#ifdef CONFIG_MEMORY_HOTPLUG + unsigned long pg_start, pfn_cnt; + unsigned long rg_start, rg_sz; +#endif + struct hv_dynmem_device *dm = &dm_device; + memset(&resp, 0, sizeof(struct dm_hot_add_response)); resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE; resp.hdr.size = sizeof(struct dm_hot_add_response); resp.hdr.trans_id = atomic_inc_return(&trans_id); - resp.page_count = 0; - resp.result = 0; +#ifdef CONFIG_MEMORY_HOTPLUG + pg_start = dm->ha_wrk.ha_page_range.finfo.start_page; + pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt; - dm_device.state = DM_INITIALIZED; - vmbus_sendpacket(dm_device.dev->channel, &resp, + rg_start = dm->ha_wrk.ha_region_range.finfo.start_page; + rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt; + + if ((rg_start == 0) && (!dm->host_specified_ha_region)) { + unsigned long region_size; + unsigned long region_start; + + /* + * The host has not specified the hot-add region. + * Based on the hot-add page range being specified, + * compute a hot-add region that can cover the pages + * that need to be hot-added while ensuring the alignment + * and size requirements of Linux as it relates to hot-add. + */ + region_start = pg_start; + region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK; + if (pfn_cnt % HA_CHUNK) + region_size += HA_CHUNK; + + region_start = (pg_start / HA_CHUNK) * HA_CHUNK; + + rg_start = region_start; + rg_sz = region_size; + } + + resp.page_count = process_hot_add(pg_start, pfn_cnt, + rg_start, rg_sz); +#endif + if (resp.page_count > 0) + resp.result = 1; + else + resp.result = 0; + + if (!do_hot_add || (resp.page_count == 0)) + pr_info("Memory hot add failed\n"); + + dm->state = DM_INITIALIZED; + vmbus_sendpacket(dm->dev->channel, &resp, sizeof(struct dm_hot_add_response), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); - } static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg) @@ -867,6 +1200,7 @@ static void balloon_onchannelcallback(void *context) struct dm_balloon *bal_msg; struct dm_hot_add *ha_msg; union dm_mem_page_range *ha_pg_range; + union dm_mem_page_range *ha_region; memset(recv_buffer, 0, sizeof(recv_buffer)); vmbus_recvpacket(dev->channel, recv_buffer, @@ -907,8 +1241,26 @@ static void balloon_onchannelcallback(void *context) pr_warn("Currently hot-adding\n"); dm->state = DM_HOT_ADD; ha_msg = (struct dm_hot_add *)recv_buffer; - ha_pg_range = &ha_msg->range; - dm_device.ha_wrk.ha_page_range = *ha_pg_range; + if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) { + /* + * This is a normal hot-add request specifying + * hot-add memory. + */ + ha_pg_range = &ha_msg->range; + dm->ha_wrk.ha_page_range = *ha_pg_range; + dm->ha_wrk.ha_region_range.page_range = 0; + } else { + /* + * Host is specifying that we first hot-add + * a region and then partially populate this + * region. + */ + dm->host_specified_ha_region = true; + ha_pg_range = &ha_msg->range; + ha_region = &ha_pg_range[1]; + dm->ha_wrk.ha_page_range = *ha_pg_range; + dm->ha_wrk.ha_region_range = *ha_region; + } schedule_work(&dm_device.ha_wrk.wrk); break; @@ -952,8 +1304,10 @@ static int balloon_probe(struct hv_device *dev, dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN7; init_completion(&dm_device.host_event); init_completion(&dm_device.config_event); + INIT_LIST_HEAD(&dm_device.ha_region_list); INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up); INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req); + dm_device.host_specified_ha_region = false; dm_device.thread = kthread_run(dm_thread_func, &dm_device, "hv_balloon"); @@ -962,6 +1316,10 @@ static int balloon_probe(struct hv_device *dev, goto probe_error1; } +#ifdef CONFIG_MEMORY_HOTPLUG + set_online_page_callback(&hv_online_page); +#endif + hv_set_drvdata(dev, &dm_device); /* * Initiate the hand shake with the host and negotiate @@ -1006,12 +1364,6 @@ static int balloon_probe(struct hv_device *dev, cap_msg.hdr.trans_id = atomic_inc_return(&trans_id); cap_msg.caps.cap_bits.balloon = 1; - /* - * While we currently don't support hot-add, - * we still advertise this capability since the - * host requires that guests partcipating in the - * dynamic memory protocol support hot add. - */ cap_msg.caps.cap_bits.hot_add = 1; /* @@ -1049,6 +1401,9 @@ static int balloon_probe(struct hv_device *dev, return 0; probe_error2: +#ifdef CONFIG_MEMORY_HOTPLUG + restore_online_page_callback(&hv_online_page); +#endif kthread_stop(dm_device.thread); probe_error1: @@ -1061,15 +1416,26 @@ probe_error0: static int balloon_remove(struct hv_device *dev) { struct hv_dynmem_device *dm = hv_get_drvdata(dev); + struct list_head *cur, *tmp; + struct hv_hotadd_state *has; if (dm->num_pages_ballooned != 0) pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned); cancel_work_sync(&dm->balloon_wrk.wrk); cancel_work_sync(&dm->ha_wrk.wrk); + vmbus_close(dev->channel); kthread_stop(dm->thread); kfree(send_buffer); +#ifdef CONFIG_MEMORY_HOTPLUG + restore_online_page_callback(&hv_online_page); +#endif + list_for_each_safe(cur, tmp, &dm->ha_region_list) { + has = list_entry(cur, struct hv_hotadd_state, list); + list_del(&has->list); + kfree(has); + } return 0; } |