diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index 3c80a21e0f913d5b090608192a31f631b02a2ae5..0a2bdaf5773b358dd5bdca59c9be0064a0d56a89 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -25,6 +25,8 @@
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <asm/hypervisor.h>
@@ -78,46 +80,94 @@ enum vmwballoon_capabilities {
| VMW_BALLOON_SIGNALLED_WAKEUP_CMD)
#define VMW_BALLOON_2M_ORDER (PMD_SHIFT - PAGE_SHIFT)
-#define VMW_BALLOON_NUM_PAGE_SIZES (2)
-/*
- * Backdoor commands availability:
+enum vmballoon_page_size_type {
+ VMW_BALLOON_4K_PAGE,
+ VMW_BALLOON_2M_PAGE,
+ VMW_BALLOON_LAST_SIZE = VMW_BALLOON_2M_PAGE
+};
+
+#define VMW_BALLOON_NUM_PAGE_SIZES (VMW_BALLOON_LAST_SIZE + 1)
+
+enum vmballoon_op_stat_type {
+ VMW_BALLOON_OP_STAT,
+ VMW_BALLOON_OP_FAIL_STAT
+};
+
+#define VMW_BALLOON_OP_STAT_TYPES (VMW_BALLOON_OP_FAIL_STAT + 1)
+
+/**
+ * enum vmballoon_cmd_type - backdoor commands.
+ *
+ * Availability of the commands is as followed:
+ *
+ * %VMW_BALLOON_CMD_START, %VMW_BALLOON_CMD_GET_TARGET and
+ * %VMW_BALLOON_CMD_GUEST_ID are always available.
+ *
+ * If the host reports %VMW_BALLOON_BASIC_CMDS are supported then
+ * %VMW_BALLOON_CMD_LOCK and %VMW_BALLOON_CMD_UNLOCK commands are available.
*
- * START, GET_TARGET and GUEST_ID are always available,
+ * If the host reports %VMW_BALLOON_BATCHED_CMDS are supported then
+ * %VMW_BALLOON_CMD_BATCHED_LOCK and VMW_BALLOON_CMD_BATCHED_UNLOCK commands
+ * are available.
*
- * VMW_BALLOON_BASIC_CMDS:
- * LOCK and UNLOCK commands,
- * VMW_BALLOON_BATCHED_CMDS:
- * BATCHED_LOCK and BATCHED_UNLOCK commands.
- * VMW BALLOON_BATCHED_2M_CMDS:
- * BATCHED_2M_LOCK and BATCHED_2M_UNLOCK commands,
- * VMW VMW_BALLOON_SIGNALLED_WAKEUP_CMD:
- * VMW_BALLOON_CMD_VMCI_DOORBELL_SET command.
+ * If the host reports %VMW_BALLOON_BATCHED_2M_CMDS are supported then
+ * %VMW_BALLOON_CMD_BATCHED_2M_LOCK and %VMW_BALLOON_CMD_BATCHED_2M_UNLOCK
+ * are supported.
+ *
+ * If the host reports VMW_BALLOON_SIGNALLED_WAKEUP_CMD is supported then
+ * VMW_BALLOON_CMD_VMCI_DOORBELL_SET command is supported.
+ *
+ * @VMW_BALLOON_CMD_START: Communicating supported version with the hypervisor.
+ * @VMW_BALLOON_CMD_GET_TARGET: Gets the balloon target size.
+ * @VMW_BALLOON_CMD_LOCK: Informs the hypervisor about a ballooned page.
+ * @VMW_BALLOON_CMD_UNLOCK: Informs the hypervisor about a page that is about
+ * to be deflated from the balloon.
+ * @VMW_BALLOON_CMD_GUEST_ID: Informs the hypervisor about the type of OS that
+ * runs in the VM.
+ * @VMW_BALLOON_CMD_BATCHED_LOCK: Inform the hypervisor about a batch of
+ * ballooned pages (up to 512).
+ * @VMW_BALLOON_CMD_BATCHED_UNLOCK: Inform the hypervisor about a batch of
+ * pages that are about to be deflated from the
+ * balloon (up to 512).
+ * @VMW_BALLOON_CMD_BATCHED_2M_LOCK: Similar to @VMW_BALLOON_CMD_BATCHED_LOCK
+ * for 2MB pages.
+ * @VMW_BALLOON_CMD_BATCHED_2M_UNLOCK: Similar to
+ * @VMW_BALLOON_CMD_BATCHED_UNLOCK for 2MB
+ * pages.
+ * @VMW_BALLOON_CMD_VMCI_DOORBELL_SET: A command to set doorbell notification
+ * that would be invoked when the balloon
+ * size changes.
+ * @VMW_BALLOON_CMD_LAST: Value of the last command.
*/
-#define VMW_BALLOON_CMD_START 0
-#define VMW_BALLOON_CMD_GET_TARGET 1
-#define VMW_BALLOON_CMD_LOCK 2
-#define VMW_BALLOON_CMD_UNLOCK 3
-#define VMW_BALLOON_CMD_GUEST_ID 4
-#define VMW_BALLOON_CMD_BATCHED_LOCK 6
-#define VMW_BALLOON_CMD_BATCHED_UNLOCK 7
-#define VMW_BALLOON_CMD_BATCHED_2M_LOCK 8
-#define VMW_BALLOON_CMD_BATCHED_2M_UNLOCK 9
-#define VMW_BALLOON_CMD_VMCI_DOORBELL_SET 10
-
-#define VMW_BALLOON_CMD_NUM 11
-
-/* error codes */
-#define VMW_BALLOON_SUCCESS 0
-#define VMW_BALLOON_FAILURE -1
-#define VMW_BALLOON_ERROR_CMD_INVALID 1
-#define VMW_BALLOON_ERROR_PPN_INVALID 2
-#define VMW_BALLOON_ERROR_PPN_LOCKED 3
-#define VMW_BALLOON_ERROR_PPN_UNLOCKED 4
-#define VMW_BALLOON_ERROR_PPN_PINNED 5
-#define VMW_BALLOON_ERROR_PPN_NOTNEEDED 6
-#define VMW_BALLOON_ERROR_RESET 7
-#define VMW_BALLOON_ERROR_BUSY 8
+enum vmballoon_cmd_type {
+ VMW_BALLOON_CMD_START,
+ VMW_BALLOON_CMD_GET_TARGET,
+ VMW_BALLOON_CMD_LOCK,
+ VMW_BALLOON_CMD_UNLOCK,
+ VMW_BALLOON_CMD_GUEST_ID,
+ /* No command 5 */
+ VMW_BALLOON_CMD_BATCHED_LOCK = 6,
+ VMW_BALLOON_CMD_BATCHED_UNLOCK,
+ VMW_BALLOON_CMD_BATCHED_2M_LOCK,
+ VMW_BALLOON_CMD_BATCHED_2M_UNLOCK,
+ VMW_BALLOON_CMD_VMCI_DOORBELL_SET,
+ VMW_BALLOON_CMD_LAST = VMW_BALLOON_CMD_VMCI_DOORBELL_SET,
+};
+
+#define VMW_BALLOON_CMD_NUM (VMW_BALLOON_CMD_LAST + 1)
+
+enum vmballoon_error_codes {
+ VMW_BALLOON_SUCCESS,
+ VMW_BALLOON_ERROR_CMD_INVALID,
+ VMW_BALLOON_ERROR_PPN_INVALID,
+ VMW_BALLOON_ERROR_PPN_LOCKED,
+ VMW_BALLOON_ERROR_PPN_UNLOCKED,
+ VMW_BALLOON_ERROR_PPN_PINNED,
+ VMW_BALLOON_ERROR_PPN_NOTNEEDED,
+ VMW_BALLOON_ERROR_RESET,
+ VMW_BALLOON_ERROR_BUSY
+};
#define VMW_BALLOON_SUCCESS_WITH_CAPABILITIES (0x03000000)
@@ -143,29 +193,28 @@ static const char * const vmballoon_cmd_names[] = {
[VMW_BALLOON_CMD_VMCI_DOORBELL_SET] = "doorbellSet"
};
-#ifdef CONFIG_DEBUG_FS
-struct vmballoon_stats {
- unsigned int timer;
- unsigned int doorbell;
-
- /* allocation statistics */
- unsigned int alloc[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int alloc_fail[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int refused_alloc[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int refused_free[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int free[VMW_BALLOON_NUM_PAGE_SIZES];
-
- /* Monitor operations. */
- unsigned long ops[VMW_BALLOON_CMD_NUM];
- unsigned long ops_fail[VMW_BALLOON_CMD_NUM];
+enum vmballoon_stat_page {
+ VMW_BALLOON_PAGE_STAT_ALLOC,
+ VMW_BALLOON_PAGE_STAT_ALLOC_FAIL,
+ VMW_BALLOON_PAGE_STAT_REFUSED_ALLOC,
+ VMW_BALLOON_PAGE_STAT_REFUSED_FREE,
+ VMW_BALLOON_PAGE_STAT_FREE,
+ VMW_BALLOON_PAGE_STAT_LAST = VMW_BALLOON_PAGE_STAT_FREE
};
-#define STATS_INC(stat) (stat)++
-#else
-#define STATS_INC(stat)
-#endif
+#define VMW_BALLOON_PAGE_STAT_NUM (VMW_BALLOON_PAGE_STAT_LAST + 1)
+
+enum vmballoon_stat_general {
+ VMW_BALLOON_STAT_TIMER,
+ VMW_BALLOON_STAT_DOORBELL,
+ VMW_BALLOON_STAT_LAST = VMW_BALLOON_STAT_DOORBELL
+};
+
+#define VMW_BALLOON_STAT_NUM (VMW_BALLOON_STAT_LAST + 1)
+
static DEFINE_STATIC_KEY_TRUE(vmw_balloon_batching);
+static DEFINE_STATIC_KEY_FALSE(balloon_stat_enabled);
struct vmballoon_page_size {
/* list of reserved physical pages */
@@ -215,10 +264,10 @@ struct vmballoon {
unsigned int batch_max_pages;
struct page *page;
-#ifdef CONFIG_DEBUG_FS
/* statistics */
- struct vmballoon_stats stats;
+ struct vmballoon_stats *stats;
+#ifdef CONFIG_DEBUG_FS
/* debugfs file exporting statistics */
struct dentry *dbg_entry;
#endif
@@ -226,17 +275,70 @@ struct vmballoon {
struct delayed_work dwork;
struct vmci_handle vmci_doorbell;
+
+ /**
+ * @conf_sem: semaphore to protect the configuration and the statistics.
+ */
+ struct rw_semaphore conf_sem;
};
static struct vmballoon balloon;
+struct vmballoon_stats {
+ /* timer / doorbell operations */
+ atomic64_t general_stat[VMW_BALLOON_STAT_NUM];
+
+ /* allocation statistics for huge and small pages */
+ atomic64_t
+ page_stat[VMW_BALLOON_PAGE_STAT_NUM][VMW_BALLOON_NUM_PAGE_SIZES];
+
+ /* Monitor operations: total operations, and failures */
+ atomic64_t ops[VMW_BALLOON_CMD_NUM][VMW_BALLOON_OP_STAT_TYPES];
+};
+
+static inline bool is_vmballoon_stats_on(void)
+{
+ return IS_ENABLED(CONFIG_DEBUG_FS) &&
+ static_branch_unlikely(&balloon_stat_enabled);
+}
+
+static inline void vmballoon_stats_op_inc(struct vmballoon *b, unsigned int op,
+ enum vmballoon_op_stat_type type)
+{
+ if (is_vmballoon_stats_on())
+ atomic64_inc(&b->stats->ops[op][type]);
+}
+
+static inline void vmballoon_stats_gen_inc(struct vmballoon *b,
+ enum vmballoon_stat_general stat)
+{
+ if (is_vmballoon_stats_on())
+ atomic64_inc(&b->stats->general_stat[stat]);
+}
+
+static inline void vmballoon_stats_gen_add(struct vmballoon *b,
+ enum vmballoon_stat_general stat,
+ unsigned int val)
+{
+ if (is_vmballoon_stats_on())
+ atomic64_add(val, &b->stats->general_stat[stat]);
+}
+
+static inline void vmballoon_stats_page_inc(struct vmballoon *b,
+ enum vmballoon_stat_page stat,
+ bool is_2m_page)
+{
+ if (is_vmballoon_stats_on())
+ atomic64_inc(&b->stats->page_stat[stat][is_2m_page]);
+}
+
static inline unsigned long
__vmballoon_cmd(struct vmballoon *b, unsigned long cmd, unsigned long arg1,
unsigned long arg2, unsigned long *result)
{
unsigned long status, dummy1, dummy2, dummy3, local_result;
- STATS_INC(b->stats.ops[cmd]);
+ vmballoon_stats_op_inc(b, cmd, VMW_BALLOON_OP_STAT);
asm volatile ("inl %%dx" :
"=a"(status),
@@ -263,7 +365,7 @@ __vmballoon_cmd(struct vmballoon *b, unsigned long cmd, unsigned long arg1,
if (status != VMW_BALLOON_SUCCESS &&
status != VMW_BALLOON_SUCCESS_WITH_CAPABILITIES) {
- STATS_INC(b->stats.ops_fail[cmd]);
+ vmballoon_stats_op_inc(b, cmd, VMW_BALLOON_OP_FAIL_STAT);
pr_debug("%s: %s [0x%lx,0x%lx) failed, returned %ld\n",
__func__, vmballoon_cmd_names[cmd], arg1, arg2,
status);
@@ -413,7 +515,8 @@ static void vmballoon_pop(struct vmballoon *b)
list_for_each_entry_safe(page, next, &page_size->pages, lru) {
list_del(&page->lru);
vmballoon_free_page(page, is_2m_pages);
- STATS_INC(b->stats.free[is_2m_pages]);
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_FREE,
+ is_2m_pages);
b->size -= size_per_page;
cond_resched();
}
@@ -534,7 +637,8 @@ static int vmballoon_lock(struct vmballoon *b, unsigned int num_pages,
}
/* Error occurred */
- STATS_INC(b->stats.refused_alloc[is_2m_pages]);
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_REFUSED_ALLOC,
+ is_2m_pages);
/*
* Place page on the list of non-balloonable pages
@@ -587,7 +691,8 @@ static int vmballoon_unlock(struct vmballoon *b, unsigned int num_pages,
} else {
/* deallocate page */
vmballoon_free_page(p, is_2m_pages);
- STATS_INC(b->stats.free[is_2m_pages]);
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_FREE,
+ is_2m_pages);
/* update balloon size */
b->size -= size_per_page;
@@ -611,7 +716,8 @@ static void vmballoon_release_refused_pages(struct vmballoon *b,
list_for_each_entry_safe(page, next, &page_size->refused_pages, lru) {
list_del(&page->lru);
vmballoon_free_page(page, is_2m_pages);
- STATS_INC(b->stats.refused_free[is_2m_pages]);
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_REFUSED_FREE,
+ is_2m_pages);
}
page_size->n_refused_pages = 0;
@@ -693,10 +799,14 @@ static void vmballoon_inflate(struct vmballoon *b)
vmballoon_change(b)) {
struct page *page;
- STATS_INC(b->stats.alloc[is_2m_pages]);
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_ALLOC,
+ is_2m_pages);
+
page = vmballoon_alloc_page(is_2m_pages);
if (!page) {
- STATS_INC(b->stats.alloc_fail[is_2m_pages]);
+ vmballoon_stats_page_inc(b,
+ VMW_BALLOON_PAGE_STAT_ALLOC_FAIL, is_2m_pages);
+
if (is_2m_pages) {
vmballoon_lock(b, num_pages, true);
@@ -845,7 +955,7 @@ static void vmballoon_doorbell(void *client_data)
{
struct vmballoon *b = client_data;
- STATS_INC(b->stats.doorbell);
+ vmballoon_stats_gen_inc(b, VMW_BALLOON_STAT_DOORBELL);
mod_delayed_work(system_freezable_wq, &b->dwork, 0);
}
@@ -903,6 +1013,8 @@ static void vmballoon_reset(struct vmballoon *b)
{
int error;
+ down_write(&b->conf_sem);
+
vmballoon_vmci_cleanup(b);
/* free all pages, skipping monitor unlock */
@@ -934,6 +1046,8 @@ static void vmballoon_reset(struct vmballoon *b)
if (!vmballoon_send_guest_id(b))
pr_err("failed to send guest ID to the host\n");
+
+ up_write(&b->conf_sem);
}
/**
@@ -950,11 +1064,18 @@ static void vmballoon_work(struct work_struct *work)
struct vmballoon *b = container_of(dwork, struct vmballoon, dwork);
int64_t change = 0;
- STATS_INC(b->stats.timer);
-
if (b->reset_required)
vmballoon_reset(b);
+ down_read(&b->conf_sem);
+
+ /*
+ * Update the stats while holding the semaphore to ensure that
+ * @stats_enabled is consistent with whether the stats are actually
+ * enabled
+ */
+ vmballoon_stats_gen_inc(b, VMW_BALLOON_STAT_TIMER);
+
if (!vmballoon_send_get_target(b))
change = vmballoon_change(b);
@@ -968,12 +1089,15 @@ static void vmballoon_work(struct work_struct *work)
vmballoon_deflate(b);
}
+ up_read(&b->conf_sem);
+
/*
* We are using a freezable workqueue so that balloon operations are
* stopped while the system transitions to/from sleep/hibernation.
*/
queue_delayed_work(system_freezable_wq,
dwork, round_jiffies_relative(HZ));
+
}
/*
@@ -981,55 +1105,105 @@ static void vmballoon_work(struct work_struct *work)
*/
#ifdef CONFIG_DEBUG_FS
+static const char * const vmballoon_stat_page_names[] = {
+ [VMW_BALLOON_PAGE_STAT_ALLOC] = "alloc",
+ [VMW_BALLOON_PAGE_STAT_ALLOC_FAIL] = "allocFail",
+ [VMW_BALLOON_PAGE_STAT_REFUSED_ALLOC] = "errAlloc",
+ [VMW_BALLOON_PAGE_STAT_REFUSED_FREE] = "errFree",
+ [VMW_BALLOON_PAGE_STAT_FREE] = "free"
+};
+
+static const char * const vmballoon_stat_names[] = {
+ [VMW_BALLOON_STAT_TIMER] = "timer",
+ [VMW_BALLOON_STAT_DOORBELL] = "doorbell"
+};
+
+static const char * const vmballoon_page_size_names[] = {
+ [VMW_BALLOON_4K_PAGE] = "4k",
+ [VMW_BALLOON_2M_PAGE] = "2M"
+};
+
+static int vmballoon_enable_stats(struct vmballoon *b)
+{
+ int r = 0;
+
+ down_write(&b->conf_sem);
+
+ /* did we somehow race with another reader which enabled stats? */
+ if (b->stats)
+ goto out;
+
+ b->stats = kzalloc(sizeof(*b->stats), GFP_KERNEL);
+
+ if (!b->stats) {
+ /* allocation failed */
+ r = -ENOMEM;
+ goto out;
+ }
+ static_key_enable(&balloon_stat_enabled.key);
+out:
+ up_write(&b->conf_sem);
+ return r;
+}
+
+/**
+ * vmballoon_debug_show - shows statistics of balloon operations.
+ * @f: pointer to the &struct seq_file.
+ * @offset: ignored.
+ *
+ * Provides the statistics that can be accessed in vmmemctl in the debugfs.
+ * To avoid the overhead - mainly that of memory - of collecting the statistics,
+ * we only collect statistics after the first time the counters are read.
+ *
+ * Return: zero on success or an error code.
+ */
static int vmballoon_debug_show(struct seq_file *f, void *offset)
{
struct vmballoon *b = f->private;
- struct vmballoon_stats *stats = &b->stats;
- int i;
+ int i, j;
+
+ /* enables stats if they are disabled */
+ if (!b->stats) {
+ int r = vmballoon_enable_stats(b);
+
+ if (r)
+ return r;
+ }
/* format capabilities info */
- seq_printf(f,
- "balloon capabilities: %#4x\n"
- "used capabilities: %#4lx\n"
- "is resetting: %c\n",
- VMW_BALLOON_CAPABILITIES, b->capabilities,
- b->reset_required ? 'y' : 'n');
+ seq_printf(f, "%-22s: %#4x\n", "balloon capabilities",
+ VMW_BALLOON_CAPABILITIES);
+ seq_printf(f, "%-22s: %#4lx\n", "used capabilities",
+ b->capabilities);
+ seq_printf(f, "%-22s: %16s\n", "is resetting",
+ b->reset_required ? "y" : "n");
/* format size info */
- seq_printf(f,
- "target: %8d pages\n"
- "current: %8d pages\n",
- b->target, b->size);
+ seq_printf(f, "%-22s: %16u\n", "target", b->target);
+ seq_printf(f, "%-22s: %16u\n", "current", b->size);
for (i = 0; i < VMW_BALLOON_CMD_NUM; i++) {
if (vmballoon_cmd_names[i] == NULL)
continue;
- seq_printf(f, "%-22s: %16lu (%lu failed)\n",
- vmballoon_cmd_names[i], stats->ops[i],
- stats->ops_fail[i]);
+ seq_printf(f, "%-22s: %16llu (%llu failed)\n",
+ vmballoon_cmd_names[i],
+ atomic64_read(&b->stats->ops[i][VMW_BALLOON_OP_STAT]),
+ atomic64_read(&b->stats->ops[i][VMW_BALLOON_OP_FAIL_STAT]));
}
- seq_printf(f,
- "\n"
- "timer: %8u\n"
- "doorbell: %8u\n"
- "prim2mAlloc: %8u (%4u failed)\n"
- "prim4kAlloc: %8u (%4u failed)\n"
- "prim2mFree: %8u\n"
- "primFree: %8u\n"
- "err2mAlloc: %8u\n"
- "errAlloc: %8u\n"
- "err2mFree: %8u\n"
- "errFree: %8u\n",
- stats->timer,
- stats->doorbell,
- stats->alloc[true], stats->alloc_fail[true],
- stats->alloc[false], stats->alloc_fail[false],
- stats->free[true],
- stats->free[false],
- stats->refused_alloc[true], stats->refused_alloc[false],
- stats->refused_free[true], stats->refused_free[false]);
+ for (i = 0; i < VMW_BALLOON_STAT_NUM; i++)
+ seq_printf(f, "%-22s: %16llu\n",
+ vmballoon_stat_names[i],
+ atomic64_read(&b->stats->general_stat[i]));
+
+ for (i = 0; i < VMW_BALLOON_PAGE_STAT_NUM; i++) {
+ for (j = 0; j < VMW_BALLOON_NUM_PAGE_SIZES; j++)
+ seq_printf(f, "%-18s(%s): %16llu\n",
+ vmballoon_stat_page_names[i],
+ vmballoon_page_size_names[j],
+ atomic64_read(&b->stats->page_stat[i][j]));
+ }
return 0;
}
@@ -1064,7 +1238,10 @@ static int __init vmballoon_debugfs_init(struct vmballoon *b)
static void __exit vmballoon_debugfs_exit(struct vmballoon *b)
{
+ static_key_disable(&balloon_stat_enabled.key);
debugfs_remove(b->dbg_entry);
+ kfree(b->stats);
+ b->stats = NULL;
}
#else
@@ -1103,6 +1280,7 @@ static int __init vmballoon_init(void)
if (error)
return error;
+ init_rwsem(&balloon.conf_sem);
balloon.vmci_doorbell = VMCI_INVALID_HANDLE;
balloon.batch_page = NULL;
balloon.page = NULL;