Drivers: hv: balloon: Implement hot-add functionality
Implement the memory hot-add functionality. With this, Linux guests can fully participate in the Dynamic Memory protocol implemented in the Windows hosts. In this version of the patch, based Olaf Herring's feedback, I have gotten rid of the module level dependency on MEMORY_HOTPLUG. Instead the code within the driver that depends on MEMORY_HOTPLUG has the appropriate compilation switches. This would allow this driver to support pure ballooning in cases where the kernel does not support memory hotplug. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>hifive-unleashed-5.1
K. Y. Srinivasan
Greg Kroah-Hartman
parent
0cf40a3e66
commit
1cac8cd4d1
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@ -412,6 +412,27 @@ struct dm_info_msg {
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* End protocol definitions.
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*/
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/*
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* State to manage hot adding memory into the guest.
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* The range start_pfn : end_pfn specifies the range
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* that the host has asked us to hot add. The range
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* start_pfn : ha_end_pfn specifies the range that we have
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* currently hot added. We hot add in multiples of 128M
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* chunks; it is possible that we may not be able to bring
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* online all the pages in the region. The range
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* covered_start_pfn : covered_end_pfn defines the pages that can
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* be brough online.
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*/
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struct hv_hotadd_state {
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struct list_head list;
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unsigned long start_pfn;
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unsigned long covered_start_pfn;
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unsigned long covered_end_pfn;
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unsigned long ha_end_pfn;
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unsigned long end_pfn;
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};
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struct balloon_state {
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__u32 num_pages;
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struct work_struct wrk;
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@ -419,16 +440,17 @@ struct balloon_state {
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struct hot_add_wrk {
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union dm_mem_page_range ha_page_range;
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union dm_mem_page_range ha_region_range;
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struct work_struct wrk;
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};
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static bool hot_add;
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static bool hot_add = true;
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static bool do_hot_add;
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/*
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* Delay reporting memory pressure by
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* the specified number of seconds.
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*/
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static uint pressure_report_delay = 30;
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static uint pressure_report_delay = 45;
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module_param(hot_add, bool, (S_IRUGO | S_IWUSR));
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MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add");
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@ -456,6 +478,7 @@ enum hv_dm_state {
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static __u8 recv_buffer[PAGE_SIZE];
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static __u8 *send_buffer;
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#define PAGES_IN_2M 512
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#define HA_CHUNK (32 * 1024)
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struct hv_dynmem_device {
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struct hv_device *dev;
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@ -478,6 +501,17 @@ struct hv_dynmem_device {
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*/
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struct hot_add_wrk ha_wrk;
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/*
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* This state tracks if the host has specified a hot-add
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* region.
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*/
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bool host_specified_ha_region;
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/*
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* State to synchronize hot-add.
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*/
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struct completion ol_waitevent;
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bool ha_waiting;
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/*
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* This thread handles hot-add
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* requests from the host as well as notifying
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@ -486,6 +520,11 @@ struct hv_dynmem_device {
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*/
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struct task_struct *thread;
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/*
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* A list of hot-add regions.
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*/
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struct list_head ha_region_list;
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/*
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* We start with the highest version we can support
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* and downgrade based on the host; we save here the
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@ -496,35 +535,329 @@ struct hv_dynmem_device {
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static struct hv_dynmem_device dm_device;
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static void hot_add_req(struct work_struct *dummy)
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#ifdef CONFIG_MEMORY_HOTPLUG
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void hv_bring_pgs_online(unsigned long start_pfn, unsigned long size)
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{
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int i;
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struct dm_hot_add_response resp;
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for (i = 0; i < size; i++) {
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struct page *pg;
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pg = pfn_to_page(start_pfn + i);
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__online_page_set_limits(pg);
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__online_page_increment_counters(pg);
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__online_page_free(pg);
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}
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}
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if (do_hot_add) {
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static void hv_mem_hot_add(unsigned long start, unsigned long size,
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unsigned long pfn_count,
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struct hv_hotadd_state *has)
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{
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int ret = 0;
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int i, nid, t;
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unsigned long start_pfn;
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unsigned long processed_pfn;
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unsigned long total_pfn = pfn_count;
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pr_info("Memory hot add not supported\n");
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for (i = 0; i < (size/HA_CHUNK); i++) {
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start_pfn = start + (i * HA_CHUNK);
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has->ha_end_pfn += HA_CHUNK;
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if (total_pfn > HA_CHUNK) {
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processed_pfn = HA_CHUNK;
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total_pfn -= HA_CHUNK;
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} else {
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processed_pfn = total_pfn;
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total_pfn = 0;
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}
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has->covered_end_pfn += processed_pfn;
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init_completion(&dm_device.ol_waitevent);
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dm_device.ha_waiting = true;
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nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
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ret = add_memory(nid, PFN_PHYS((start_pfn)),
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(HA_CHUNK << PAGE_SHIFT));
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if (ret) {
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pr_info("hot_add memory failed error is %d\n", ret);
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has->ha_end_pfn -= HA_CHUNK;
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has->covered_end_pfn -= processed_pfn;
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break;
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}
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/*
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* Currently we do not support hot add.
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* Just fail the request.
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* Wait for the memory block to be onlined.
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*/
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t = wait_for_completion_timeout(&dm_device.ol_waitevent, 5*HZ);
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if (t == 0) {
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pr_info("hot_add memory timedout\n");
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has->ha_end_pfn -= HA_CHUNK;
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has->covered_end_pfn -= processed_pfn;
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break;
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}
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}
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return;
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}
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static void hv_online_page(struct page *pg)
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{
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struct list_head *cur;
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struct hv_hotadd_state *has;
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unsigned long cur_start_pgp;
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unsigned long cur_end_pgp;
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if (dm_device.ha_waiting) {
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dm_device.ha_waiting = false;
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complete(&dm_device.ol_waitevent);
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}
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list_for_each(cur, &dm_device.ha_region_list) {
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has = list_entry(cur, struct hv_hotadd_state, list);
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cur_start_pgp = (unsigned long)
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pfn_to_page(has->covered_start_pfn);
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cur_end_pgp = (unsigned long)pfn_to_page(has->covered_end_pfn);
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if (((unsigned long)pg >= cur_start_pgp) &&
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((unsigned long)pg < cur_end_pgp)) {
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/*
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* This frame is currently backed; online the
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* page.
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*/
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__online_page_set_limits(pg);
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__online_page_increment_counters(pg);
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__online_page_free(pg);
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has->covered_start_pfn++;
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}
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}
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}
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static bool pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt)
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{
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struct list_head *cur;
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struct hv_hotadd_state *has;
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unsigned long residual, new_inc;
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if (list_empty(&dm_device.ha_region_list))
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return false;
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list_for_each(cur, &dm_device.ha_region_list) {
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has = list_entry(cur, struct hv_hotadd_state, list);
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/*
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* If the pfn range we are dealing with is not in the current
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* "hot add block", move on.
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*/
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if ((start_pfn >= has->end_pfn))
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continue;
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/*
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* If the current hot add-request extends beyond
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* our current limit; extend it.
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*/
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if ((start_pfn + pfn_cnt) > has->end_pfn) {
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residual = (start_pfn + pfn_cnt - has->end_pfn);
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/*
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* Extend the region by multiples of HA_CHUNK.
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*/
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new_inc = (residual / HA_CHUNK) * HA_CHUNK;
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if (residual % HA_CHUNK)
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new_inc += HA_CHUNK;
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has->end_pfn += new_inc;
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}
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/*
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* If the current start pfn is not where the covered_end
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* is, update it.
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*/
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if (has->covered_end_pfn != start_pfn) {
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has->covered_end_pfn = start_pfn;
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has->covered_start_pfn = start_pfn;
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}
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return true;
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}
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return false;
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}
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static unsigned long handle_pg_range(unsigned long pg_start,
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unsigned long pg_count)
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{
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unsigned long start_pfn = pg_start;
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unsigned long pfn_cnt = pg_count;
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unsigned long size;
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struct list_head *cur;
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struct hv_hotadd_state *has;
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unsigned long pgs_ol = 0;
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unsigned long old_covered_state;
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if (list_empty(&dm_device.ha_region_list))
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return 0;
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list_for_each(cur, &dm_device.ha_region_list) {
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has = list_entry(cur, struct hv_hotadd_state, list);
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/*
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* If the pfn range we are dealing with is not in the current
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* "hot add block", move on.
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*/
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if ((start_pfn >= has->end_pfn))
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continue;
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old_covered_state = has->covered_end_pfn;
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if (start_pfn < has->ha_end_pfn) {
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/*
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* This is the case where we are backing pages
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* in an already hot added region. Bring
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* these pages online first.
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*/
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pgs_ol = has->ha_end_pfn - start_pfn;
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if (pgs_ol > pfn_cnt)
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pgs_ol = pfn_cnt;
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hv_bring_pgs_online(start_pfn, pgs_ol);
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has->covered_end_pfn += pgs_ol;
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has->covered_start_pfn += pgs_ol;
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pfn_cnt -= pgs_ol;
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}
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if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) {
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/*
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* We have some residual hot add range
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* that needs to be hot added; hot add
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* it now. Hot add a multiple of
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* of HA_CHUNK that fully covers the pages
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* we have.
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*/
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size = (has->end_pfn - has->ha_end_pfn);
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if (pfn_cnt <= size) {
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size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK);
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if (pfn_cnt % HA_CHUNK)
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size += HA_CHUNK;
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} else {
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pfn_cnt = size;
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}
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hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has);
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}
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/*
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* If we managed to online any pages that were given to us,
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* we declare success.
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*/
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return has->covered_end_pfn - old_covered_state;
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}
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return 0;
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}
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static unsigned long process_hot_add(unsigned long pg_start,
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unsigned long pfn_cnt,
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unsigned long rg_start,
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unsigned long rg_size)
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{
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struct hv_hotadd_state *ha_region = NULL;
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if (pfn_cnt == 0)
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return 0;
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if (!dm_device.host_specified_ha_region)
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if (pfn_covered(pg_start, pfn_cnt))
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goto do_pg_range;
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/*
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* If the host has specified a hot-add range; deal with it first.
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*/
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if ((rg_size != 0) && (!dm_device.host_specified_ha_region)) {
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ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL);
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if (!ha_region)
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return 0;
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INIT_LIST_HEAD(&ha_region->list);
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list_add_tail(&ha_region->list, &dm_device.ha_region_list);
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ha_region->start_pfn = rg_start;
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ha_region->ha_end_pfn = rg_start;
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ha_region->covered_start_pfn = pg_start;
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ha_region->covered_end_pfn = pg_start;
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ha_region->end_pfn = rg_start + rg_size;
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}
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do_pg_range:
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/*
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* Process the page range specified; bringing them
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* online if possible.
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*/
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return handle_pg_range(pg_start, pfn_cnt);
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}
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#endif
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static void hot_add_req(struct work_struct *dummy)
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{
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struct dm_hot_add_response resp;
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#ifdef CONFIG_MEMORY_HOTPLUG
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unsigned long pg_start, pfn_cnt;
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unsigned long rg_start, rg_sz;
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#endif
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struct hv_dynmem_device *dm = &dm_device;
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memset(&resp, 0, sizeof(struct dm_hot_add_response));
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resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE;
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resp.hdr.size = sizeof(struct dm_hot_add_response);
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resp.hdr.trans_id = atomic_inc_return(&trans_id);
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resp.page_count = 0;
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resp.result = 0;
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#ifdef CONFIG_MEMORY_HOTPLUG
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pg_start = dm->ha_wrk.ha_page_range.finfo.start_page;
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pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt;
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dm_device.state = DM_INITIALIZED;
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vmbus_sendpacket(dm_device.dev->channel, &resp,
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rg_start = dm->ha_wrk.ha_region_range.finfo.start_page;
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rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt;
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if ((rg_start == 0) && (!dm->host_specified_ha_region)) {
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unsigned long region_size;
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unsigned long region_start;
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/*
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* The host has not specified the hot-add region.
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* Based on the hot-add page range being specified,
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* compute a hot-add region that can cover the pages
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* that need to be hot-added while ensuring the alignment
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* and size requirements of Linux as it relates to hot-add.
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*/
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region_start = pg_start;
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region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK;
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if (pfn_cnt % HA_CHUNK)
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region_size += HA_CHUNK;
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region_start = (pg_start / HA_CHUNK) * HA_CHUNK;
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rg_start = region_start;
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rg_sz = region_size;
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}
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resp.page_count = process_hot_add(pg_start, pfn_cnt,
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rg_start, rg_sz);
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#endif
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if (resp.page_count > 0)
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resp.result = 1;
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else
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resp.result = 0;
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if (!do_hot_add || (resp.page_count == 0))
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pr_info("Memory hot add failed\n");
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dm->state = DM_INITIALIZED;
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vmbus_sendpacket(dm->dev->channel, &resp,
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sizeof(struct dm_hot_add_response),
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(unsigned long)NULL,
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VM_PKT_DATA_INBAND, 0);
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}
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static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg)
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@ -867,6 +1200,7 @@ static void balloon_onchannelcallback(void *context)
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struct dm_balloon *bal_msg;
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struct dm_hot_add *ha_msg;
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union dm_mem_page_range *ha_pg_range;
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union dm_mem_page_range *ha_region;
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memset(recv_buffer, 0, sizeof(recv_buffer));
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vmbus_recvpacket(dev->channel, recv_buffer,
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@ -907,8 +1241,26 @@ static void balloon_onchannelcallback(void *context)
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pr_warn("Currently hot-adding\n");
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dm->state = DM_HOT_ADD;
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ha_msg = (struct dm_hot_add *)recv_buffer;
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ha_pg_range = &ha_msg->range;
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dm_device.ha_wrk.ha_page_range = *ha_pg_range;
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if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) {
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/*
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* This is a normal hot-add request specifying
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* hot-add memory.
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*/
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ha_pg_range = &ha_msg->range;
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dm->ha_wrk.ha_page_range = *ha_pg_range;
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dm->ha_wrk.ha_region_range.page_range = 0;
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} else {
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/*
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* Host is specifying that we first hot-add
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* a region and then partially populate this
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* region.
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*/
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dm->host_specified_ha_region = true;
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ha_pg_range = &ha_msg->range;
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ha_region = &ha_pg_range[1];
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dm->ha_wrk.ha_page_range = *ha_pg_range;
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dm->ha_wrk.ha_region_range = *ha_region;
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}
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schedule_work(&dm_device.ha_wrk.wrk);
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break;
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@ -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;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue