Merge tag 'hyperv-fixes-signed-20220407' of git://git.kernel.org/pub/scm/linux/kernel...

[sfrench/cifs-2.6.git] / drivers / hv / hv_balloon.c

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 439f99b8b5de269bdc2c0574d4eaae2521e9d50f..3248b48f37f6128aa1dd58ff6db3582edaa5f362 100644 (file)
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/kthread.h>
 #include <linux/completion.h>
+#include <linux/count_zeros.h>
 #include <linux/memory_hotplug.h>
 #include <linux/memory.h>
 #include <linux/notifier.h>
@@ -1130,6 +1131,7 @@ static void post_status(struct hv_dynmem_device *dm)
        struct dm_status status;
        unsigned long now = jiffies;
        unsigned long last_post = last_post_time;
+       unsigned long num_pages_avail, num_pages_committed;
 
        if (pressure_report_delay > 0) {
                --pressure_report_delay;
@@ -1154,16 +1156,21 @@ static void post_status(struct hv_dynmem_device *dm)
         * num_pages_onlined) as committed to the host, otherwise it can try
         * asking us to balloon them out.
         */
-       status.num_avail = si_mem_available();
-       status.num_committed = vm_memory_committed() +
+       num_pages_avail = si_mem_available();
+       num_pages_committed = vm_memory_committed() +
                dm->num_pages_ballooned +
                (dm->num_pages_added > dm->num_pages_onlined ?
                 dm->num_pages_added - dm->num_pages_onlined : 0) +
                compute_balloon_floor();
 
-       trace_balloon_status(status.num_avail, status.num_committed,
+       trace_balloon_status(num_pages_avail, num_pages_committed,
                             vm_memory_committed(), dm->num_pages_ballooned,
                             dm->num_pages_added, dm->num_pages_onlined);
+
+       /* Convert numbers of pages into numbers of HV_HYP_PAGEs. */
+       status.num_avail = num_pages_avail * NR_HV_HYP_PAGES_IN_PAGE;
+       status.num_committed = num_pages_committed * NR_HV_HYP_PAGES_IN_PAGE;
+
        /*
         * If our transaction ID is no longer current, just don't
         * send the status. This can happen if we were interrupted
@@ -1653,6 +1660,38 @@ static void disable_page_reporting(void)
        }
 }
 
+static int ballooning_enabled(void)
+{
+       /*
+        * Disable ballooning if the page size is not 4k (HV_HYP_PAGE_SIZE),
+        * since currently it's unclear to us whether an unballoon request can
+        * make sure all page ranges are guest page size aligned.
+        */
+       if (PAGE_SIZE != HV_HYP_PAGE_SIZE) {
+               pr_info("Ballooning disabled because page size is not 4096 bytes\n");
+               return 0;
+       }
+
+       return 1;
+}
+
+static int hot_add_enabled(void)
+{
+       /*
+        * Disable hot add on ARM64, because we currently rely on
+        * memory_add_physaddr_to_nid() to get a node id of a hot add range,
+        * however ARM64's memory_add_physaddr_to_nid() always return 0 and
+        * DM_MEM_HOT_ADD_REQUEST doesn't have the NUMA node information for
+        * add_memory().
+        */
+       if (IS_ENABLED(CONFIG_ARM64)) {
+               pr_info("Memory hot add disabled on ARM64\n");
+               return 0;
+       }
+
+       return 1;
+}
+
 static int balloon_connect_vsp(struct hv_device *dev)
 {
        struct dm_version_request version_req;
@@ -1724,8 +1763,8 @@ static int balloon_connect_vsp(struct hv_device *dev)
         * currently still requires the bits to be set, so we have to add code
         * to fail the host's hot-add and balloon up/down requests, if any.
         */
-       cap_msg.caps.cap_bits.balloon = 1;
-       cap_msg.caps.cap_bits.hot_add = 1;
+       cap_msg.caps.cap_bits.balloon = ballooning_enabled();
+       cap_msg.caps.cap_bits.hot_add = hot_add_enabled();
 
        /*
         * Specify our alignment requirements as it relates