diff options
Diffstat (limited to 'drivers/hv/hv_balloon.c')
| -rw-r--r-- | drivers/hv/hv_balloon.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 2f776d78e3c1..58af84e30144 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -21,6 +21,7 @@ #include <linux/memory.h> #include <linux/notifier.h> #include <linux/percpu_counter.h> +#include <linux/page_reporting.h> #include <linux/hyperv.h> #include <asm/hyperv-tlfs.h> @@ -563,6 +564,8 @@ struct hv_dynmem_device { * The negotiated version agreed by host. */ __u32 version; + + struct page_reporting_dev_info pr_dev_info; }; static struct hv_dynmem_device dm_device; @@ -1568,6 +1571,89 @@ static void balloon_onchannelcallback(void *context) } +/* Hyper-V only supports reporting 2MB pages or higher */ +#define HV_MIN_PAGE_REPORTING_ORDER 9 +#define HV_MIN_PAGE_REPORTING_LEN (HV_HYP_PAGE_SIZE << HV_MIN_PAGE_REPORTING_ORDER) +static int hv_free_page_report(struct page_reporting_dev_info *pr_dev_info, + struct scatterlist *sgl, unsigned int nents) +{ + unsigned long flags; + struct hv_memory_hint *hint; + int i; + u64 status; + struct scatterlist *sg; + + WARN_ON_ONCE(nents > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES); + WARN_ON_ONCE(sgl->length < HV_MIN_PAGE_REPORTING_LEN); + local_irq_save(flags); + hint = *(struct hv_memory_hint **)this_cpu_ptr(hyperv_pcpu_input_arg); + if (!hint) { + local_irq_restore(flags); + return -ENOSPC; + } + + hint->type = HV_EXT_MEMORY_HEAT_HINT_TYPE_COLD_DISCARD; + hint->reserved = 0; + for_each_sg(sgl, sg, nents, i) { + union hv_gpa_page_range *range; + + range = &hint->ranges[i]; + range->address_space = 0; + /* page reporting only reports 2MB pages or higher */ + range->page.largepage = 1; + range->page.additional_pages = + (sg->length / HV_MIN_PAGE_REPORTING_LEN) - 1; + range->page_size = HV_GPA_PAGE_RANGE_PAGE_SIZE_2MB; + range->base_large_pfn = + page_to_hvpfn(sg_page(sg)) >> HV_MIN_PAGE_REPORTING_ORDER; + } + + status = hv_do_rep_hypercall(HV_EXT_CALL_MEMORY_HEAT_HINT, nents, 0, + hint, NULL); + local_irq_restore(flags); + if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS) { + pr_err("Cold memory discard hypercall failed with status %llx\n", + status); + return -EINVAL; + } + + return 0; +} + +static void enable_page_reporting(void) +{ + int ret; + + /* Essentially, validating 'PAGE_REPORTING_MIN_ORDER' is big enough. */ + if (pageblock_order < HV_MIN_PAGE_REPORTING_ORDER) { + pr_debug("Cold memory discard is only supported on 2MB pages and above\n"); + return; + } + + if (!hv_query_ext_cap(HV_EXT_CAPABILITY_MEMORY_COLD_DISCARD_HINT)) { + pr_debug("Cold memory discard hint not supported by Hyper-V\n"); + return; + } + + BUILD_BUG_ON(PAGE_REPORTING_CAPACITY > HV_MEMORY_HINT_MAX_GPA_PAGE_RANGES); + dm_device.pr_dev_info.report = hv_free_page_report; + ret = page_reporting_register(&dm_device.pr_dev_info); + if (ret < 0) { + dm_device.pr_dev_info.report = NULL; + pr_err("Failed to enable cold memory discard: %d\n", ret); + } else { + pr_info("Cold memory discard hint enabled\n"); + } +} + +static void disable_page_reporting(void) +{ + if (dm_device.pr_dev_info.report) { + page_reporting_unregister(&dm_device.pr_dev_info); + dm_device.pr_dev_info.report = NULL; + } +} + static int balloon_connect_vsp(struct hv_device *dev) { struct dm_version_request version_req; @@ -1713,6 +1799,7 @@ static int balloon_probe(struct hv_device *dev, if (ret != 0) return ret; + enable_page_reporting(); dm_device.state = DM_INITIALIZED; dm_device.thread = @@ -1727,6 +1814,7 @@ static int balloon_probe(struct hv_device *dev, probe_error: dm_device.state = DM_INIT_ERROR; dm_device.thread = NULL; + disable_page_reporting(); vmbus_close(dev->channel); #ifdef CONFIG_MEMORY_HOTPLUG unregister_memory_notifier(&hv_memory_nb); @@ -1749,6 +1837,7 @@ static int balloon_remove(struct hv_device *dev) cancel_work_sync(&dm->ha_wrk.wrk); kthread_stop(dm->thread); + disable_page_reporting(); vmbus_close(dev->channel); #ifdef CONFIG_MEMORY_HOTPLUG unregister_memory_notifier(&hv_memory_nb); |