#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/rwsem.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <linux/vmw_vmci_defs.h>
#include <linux/vmw_vmci_api.h>
#include <asm/hypervisor.h>
MODULE_LICENSE("GPL");
/*
- * Use __GFP_HIGHMEM to allow pages from HIGHMEM zone. We don't
- * allow wait (__GFP_RECLAIM) for NOSLEEP page allocations. Use
- * __GFP_NOWARN, to suppress page allocation failure warnings.
+ * Use __GFP_HIGHMEM to allow pages from HIGHMEM zone. We don't allow wait
+ * (__GFP_RECLAIM) for huge page allocations. Use __GFP_NOWARN, to suppress page
+ * allocation failure warnings. Disallow access to emergency low-memory pools.
*/
-#define VMW_PAGE_ALLOC_NOSLEEP (__GFP_HIGHMEM|__GFP_NOWARN)
+#define VMW_HUGE_PAGE_ALLOC_FLAGS (__GFP_HIGHMEM|__GFP_NOWARN| \
+ __GFP_NOMEMALLOC)
/*
- * Use GFP_HIGHUSER when executing in a separate kernel thread
- * context and allocation can sleep. This is less stressful to
- * the guest memory system, since it allows the thread to block
- * while memory is reclaimed, and won't take pages from emergency
- * low-memory pools.
+ * Use __GFP_HIGHMEM to allow pages from HIGHMEM zone. We allow lightweight
+ * reclamation (__GFP_NORETRY). Use __GFP_NOWARN, to suppress page allocation
+ * failure warnings. Disallow access to emergency low-memory pools.
*/
-#define VMW_PAGE_ALLOC_CANSLEEP (GFP_HIGHUSER)
+#define VMW_PAGE_ALLOC_FLAGS (__GFP_HIGHMEM|__GFP_NOWARN| \
+ __GFP_NOMEMALLOC|__GFP_NORETRY)
/* Maximum number of refused pages we accumulate during inflation cycle */
#define VMW_BALLOON_MAX_REFUSED 16
| VMW_BALLOON_BATCHED_2M_CMDS \
| VMW_BALLOON_SIGNALLED_WAKEUP_CMD)
-#define VMW_BALLOON_2M_SHIFT (9)
-#define VMW_BALLOON_NUM_PAGE_SIZES (2)
+#define VMW_BALLOON_2M_ORDER (PMD_SHIFT - PAGE_SHIFT)
-/*
- * Backdoor commands availability:
- *
- * START, GET_TARGET and GUEST_ID are always 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.
- */
-#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
-
-
-/* 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_page_size_type {
+ VMW_BALLOON_4K_PAGE,
+ VMW_BALLOON_2M_PAGE,
+ VMW_BALLOON_LAST_SIZE = VMW_BALLOON_2M_PAGE
+};
-#define VMW_BALLOON_SUCCESS_WITH_CAPABILITIES (0x03000000)
+#define VMW_BALLOON_NUM_PAGE_SIZES (VMW_BALLOON_LAST_SIZE + 1)
-/* Batch page description */
+static const char * const vmballoon_page_size_names[] = {
+ [VMW_BALLOON_4K_PAGE] = "4k",
+ [VMW_BALLOON_2M_PAGE] = "2M"
+};
-/*
- * Layout of a page in the batch page:
+enum vmballoon_op {
+ VMW_BALLOON_INFLATE,
+ VMW_BALLOON_DEFLATE
+};
+
+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.
*
- * +-------------+----------+--------+
- * | | | |
- * | Page number | Reserved | Status |
- * | | | |
- * +-------------+----------+--------+
- * 64 PAGE_SHIFT 6 0
+ * Availability of the commands is as followed:
*
- * The reserved field should be set to 0.
+ * %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.
+ *
+ * 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.
+ *
+ * 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_BATCH_MAX_PAGES (PAGE_SIZE / sizeof(u64))
-#define VMW_BALLOON_BATCH_STATUS_MASK ((1UL << 5) - 1)
-#define VMW_BALLOON_BATCH_PAGE_MASK (~((1UL << PAGE_SHIFT) - 1))
-
-struct vmballoon_batch_page {
- u64 pages[VMW_BALLOON_BATCH_MAX_PAGES];
+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,
};
-static u64 vmballoon_batch_get_pa(struct vmballoon_batch_page *batch, int idx)
-{
- return batch->pages[idx] & VMW_BALLOON_BATCH_PAGE_MASK;
-}
+#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
+};
-static int vmballoon_batch_get_status(struct vmballoon_batch_page *batch,
- int idx)
-{
- return (int)(batch->pages[idx] & VMW_BALLOON_BATCH_STATUS_MASK);
-}
+#define VMW_BALLOON_SUCCESS_WITH_CAPABILITIES (0x03000000)
-static void vmballoon_batch_set_pa(struct vmballoon_batch_page *batch, int idx,
- u64 pa)
-{
- batch->pages[idx] = pa;
-}
+#define VMW_BALLOON_CMD_WITH_TARGET_MASK \
+ ((1UL << VMW_BALLOON_CMD_GET_TARGET) | \
+ (1UL << VMW_BALLOON_CMD_LOCK) | \
+ (1UL << VMW_BALLOON_CMD_UNLOCK) | \
+ (1UL << VMW_BALLOON_CMD_BATCHED_LOCK) | \
+ (1UL << VMW_BALLOON_CMD_BATCHED_UNLOCK) | \
+ (1UL << VMW_BALLOON_CMD_BATCHED_2M_LOCK) | \
+ (1UL << VMW_BALLOON_CMD_BATCHED_2M_UNLOCK))
+
+static const char * const vmballoon_cmd_names[] = {
+ [VMW_BALLOON_CMD_START] = "start",
+ [VMW_BALLOON_CMD_GET_TARGET] = "target",
+ [VMW_BALLOON_CMD_LOCK] = "lock",
+ [VMW_BALLOON_CMD_UNLOCK] = "unlock",
+ [VMW_BALLOON_CMD_GUEST_ID] = "guestType",
+ [VMW_BALLOON_CMD_BATCHED_LOCK] = "batchLock",
+ [VMW_BALLOON_CMD_BATCHED_UNLOCK] = "batchUnlock",
+ [VMW_BALLOON_CMD_BATCHED_2M_LOCK] = "2m-lock",
+ [VMW_BALLOON_CMD_BATCHED_2M_UNLOCK] = "2m-unlock",
+ [VMW_BALLOON_CMD_VMCI_DOORBELL_SET] = "doorbellSet"
+};
+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 VMWARE_BALLOON_CMD(cmd, arg1, arg2, result) \
-({ \
- unsigned long __status, __dummy1, __dummy2, __dummy3; \
- __asm__ __volatile__ ("inl %%dx" : \
- "=a"(__status), \
- "=c"(__dummy1), \
- "=d"(__dummy2), \
- "=b"(result), \
- "=S" (__dummy3) : \
- "0"(VMW_BALLOON_HV_MAGIC), \
- "1"(VMW_BALLOON_CMD_##cmd), \
- "2"(VMW_BALLOON_HV_PORT), \
- "3"(arg1), \
- "4" (arg2) : \
- "memory"); \
- if (VMW_BALLOON_CMD_##cmd == VMW_BALLOON_CMD_START) \
- result = __dummy1; \
- result &= -1UL; \
- __status & -1UL; \
-})
+#define VMW_BALLOON_PAGE_STAT_NUM (VMW_BALLOON_PAGE_STAT_LAST + 1)
-#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 sleep_alloc;
- unsigned int sleep_alloc_fail;
- 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 int lock[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int lock_fail[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int unlock[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int unlock_fail[VMW_BALLOON_NUM_PAGE_SIZES];
- unsigned int target;
- unsigned int target_fail;
- unsigned int start;
- unsigned int start_fail;
- unsigned int guest_type;
- unsigned int guest_type_fail;
- unsigned int doorbell_set;
- unsigned int doorbell_unset;
+enum vmballoon_stat_general {
+ VMW_BALLOON_STAT_TIMER,
+ VMW_BALLOON_STAT_DOORBELL,
+ VMW_BALLOON_STAT_RESET,
+ VMW_BALLOON_STAT_LAST = VMW_BALLOON_STAT_RESET
};
-#define STATS_INC(stat) (stat)++
-#else
-#define STATS_INC(stat)
-#endif
+#define VMW_BALLOON_STAT_NUM (VMW_BALLOON_STAT_LAST + 1)
-struct vmballoon;
-struct vmballoon_ops {
- void (*add_page)(struct vmballoon *b, int idx, struct page *p);
- int (*lock)(struct vmballoon *b, unsigned int num_pages,
- bool is_2m_pages, unsigned int *target);
- int (*unlock)(struct vmballoon *b, unsigned int num_pages,
- bool is_2m_pages, unsigned int *target);
+static DEFINE_STATIC_KEY_TRUE(vmw_balloon_batching);
+static DEFINE_STATIC_KEY_FALSE(balloon_stat_enabled);
+
+struct vmballoon_ctl {
+ struct list_head pages;
+ struct list_head refused_pages;
+ unsigned int n_refused_pages;
+ unsigned int n_pages;
+ enum vmballoon_page_size_type page_size;
+ enum vmballoon_op op;
};
struct vmballoon_page_size {
/* list of reserved physical pages */
struct list_head pages;
-
- /* transient list of non-balloonable pages */
- struct list_head refused_pages;
- unsigned int n_refused_pages;
};
+/**
+ * struct vmballoon_batch_entry - a batch entry for lock or unlock.
+ *
+ * @status: the status of the operation, which is written by the hypervisor.
+ * @reserved: reserved for future use. Must be set to zero.
+ * @pfn: the physical frame number of the page to be locked or unlocked.
+ */
+struct vmballoon_batch_entry {
+ u64 status : 5;
+ u64 reserved : PAGE_SHIFT - 5;
+ u64 pfn : 52;
+} __packed;
+
struct vmballoon {
struct vmballoon_page_size page_sizes[VMW_BALLOON_NUM_PAGE_SIZES];
- /* supported page sizes. 1 == 4k pages only, 2 == 4k and 2m pages */
- unsigned supported_page_sizes;
+ /**
+ * @max_page_size: maximum supported page size for ballooning.
+ *
+ * Protected by @conf_sem
+ */
+ enum vmballoon_page_size_type max_page_size;
+
+ /**
+ * @size: balloon actual size in basic page size (frames).
+ *
+ * While we currently do not support size which is bigger than 32-bit,
+ * in preparation for future support, use 64-bits.
+ */
+ atomic64_t size;
- /* balloon size in pages */
- unsigned int size;
- unsigned int target;
+ /**
+ * @target: balloon target size in basic page size (frames).
+ *
+ * We do not protect the target under the assumption that setting the
+ * value is always done through a single write. If this assumption ever
+ * breaks, we would have to use X_ONCE for accesses, and suffer the less
+ * optimized code. Although we may read stale target value if multiple
+ * accesses happen at once, the performance impact should be minor.
+ */
+ unsigned long target;
- /* reset flag */
+ /**
+ * @reset_required: reset flag
+ *
+ * Setting this flag may introduce races, but the code is expected to
+ * handle them gracefully. In the worst case, another operation will
+ * fail as reset did not take place. Clearing the flag is done while
+ * holding @conf_sem for write.
+ */
bool reset_required;
+ /**
+ * @capabilities: hypervisor balloon capabilities.
+ *
+ * Protected by @conf_sem.
+ */
unsigned long capabilities;
- struct vmballoon_batch_page *batch_page;
+ /**
+ * @batch_page: pointer to communication batch page.
+ *
+ * When batching is used, batch_page points to a page, which holds up to
+ * %VMW_BALLOON_BATCH_MAX_PAGES entries for locking or unlocking.
+ */
+ struct vmballoon_batch_entry *batch_page;
+
+ /**
+ * @batch_max_pages: maximum pages that can be locked/unlocked.
+ *
+ * Indicates the number of pages that the hypervisor can lock or unlock
+ * at once, according to whether batching is enabled. If batching is
+ * disabled, only a single page can be locked/unlock on each operation.
+ *
+ * Protected by @conf_sem.
+ */
unsigned int batch_max_pages;
- struct page *page;
- const struct vmballoon_ops *ops;
+ /**
+ * @page: page to be locked/unlocked by the hypervisor
+ *
+ * @page is only used when batching is disabled and a single page is
+ * reclaimed on each iteration.
+ *
+ * Protected by @comm_lock.
+ */
+ 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
- struct sysinfo sysinfo;
-
struct delayed_work dwork;
+ /**
+ * @vmci_doorbell.
+ *
+ * Protected by @conf_sem.
+ */
struct vmci_handle vmci_doorbell;
+
+ /**
+ * @conf_sem: semaphore to protect the configuration and the statistics.
+ */
+ struct rw_semaphore conf_sem;
+
+ /**
+ * @comm_lock: lock to protect the communication with the host.
+ *
+ * Lock ordering: @conf_sem -> @comm_lock .
+ */
+ spinlock_t comm_lock;
};
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,
+ enum vmballoon_page_size_type size)
+{
+ if (is_vmballoon_stats_on())
+ atomic64_inc(&b->stats->page_stat[stat][size]);
+}
+
+static inline void vmballoon_stats_page_add(struct vmballoon *b,
+ enum vmballoon_stat_page stat,
+ enum vmballoon_page_size_type size,
+ unsigned int val)
+{
+ if (is_vmballoon_stats_on())
+ atomic64_add(val, &b->stats->page_stat[stat][size]);
+}
+
+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;
+
+ vmballoon_stats_op_inc(b, cmd, VMW_BALLOON_OP_STAT);
+
+ asm volatile ("inl %%dx" :
+ "=a"(status),
+ "=c"(dummy1),
+ "=d"(dummy2),
+ "=b"(local_result),
+ "=S"(dummy3) :
+ "0"(VMW_BALLOON_HV_MAGIC),
+ "1"(cmd),
+ "2"(VMW_BALLOON_HV_PORT),
+ "3"(arg1),
+ "4"(arg2) :
+ "memory");
+
+ /* update the result if needed */
+ if (result)
+ *result = (cmd == VMW_BALLOON_CMD_START) ? dummy1 :
+ local_result;
+
+ /* update target when applicable */
+ if (status == VMW_BALLOON_SUCCESS &&
+ ((1ul << cmd) & VMW_BALLOON_CMD_WITH_TARGET_MASK))
+ WRITE_ONCE(b->target, local_result);
+
+ if (status != VMW_BALLOON_SUCCESS &&
+ status != VMW_BALLOON_SUCCESS_WITH_CAPABILITIES) {
+ 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);
+ }
+
+ /* mark reset required accordingly */
+ if (status == VMW_BALLOON_ERROR_RESET)
+ b->reset_required = true;
+
+ return status;
+}
+
+static __always_inline unsigned long
+vmballoon_cmd(struct vmballoon *b, unsigned long cmd, unsigned long arg1,
+ unsigned long arg2)
+{
+ unsigned long dummy;
+
+ return __vmballoon_cmd(b, cmd, arg1, arg2, &dummy);
+}
+
/*
* Send "start" command to the host, communicating supported version
* of the protocol.
*/
-static bool vmballoon_send_start(struct vmballoon *b, unsigned long req_caps)
+static int vmballoon_send_start(struct vmballoon *b, unsigned long req_caps)
{
- unsigned long status, capabilities, dummy = 0;
- bool success;
-
- STATS_INC(b->stats.start);
+ unsigned long status, capabilities;
- status = VMWARE_BALLOON_CMD(START, req_caps, dummy, capabilities);
+ status = __vmballoon_cmd(b, VMW_BALLOON_CMD_START, req_caps, 0,
+ &capabilities);
switch (status) {
case VMW_BALLOON_SUCCESS_WITH_CAPABILITIES:
b->capabilities = capabilities;
- success = true;
break;
case VMW_BALLOON_SUCCESS:
b->capabilities = VMW_BALLOON_BASIC_CMDS;
- success = true;
break;
default:
- success = false;
+ return -EIO;
}
/*
* reason disabled, do not use 2MB pages, since otherwise the legacy
* mechanism is used with 2MB pages, causing a failure.
*/
+ b->max_page_size = VMW_BALLOON_4K_PAGE;
if ((b->capabilities & VMW_BALLOON_BATCHED_2M_CMDS) &&
(b->capabilities & VMW_BALLOON_BATCHED_CMDS))
- b->supported_page_sizes = 2;
- else
- b->supported_page_sizes = 1;
-
- if (!success) {
- pr_debug("%s - failed, hv returns %ld\n", __func__, status);
- STATS_INC(b->stats.start_fail);
- }
- return success;
-}
+ b->max_page_size = VMW_BALLOON_2M_PAGE;
-static bool vmballoon_check_status(struct vmballoon *b, unsigned long status)
-{
- switch (status) {
- case VMW_BALLOON_SUCCESS:
- return true;
- case VMW_BALLOON_ERROR_RESET:
- b->reset_required = true;
- /* fall through */
-
- default:
- return false;
- }
+ return 0;
}
-/*
+/**
+ * vmballoon_send_guest_id - communicate guest type to the host.
+ *
+ * @b: pointer to the balloon.
+ *
* Communicate guest type to the host so that it can adjust ballooning
* algorithm to the one most appropriate for the guest. This command
* is normally issued after sending "start" command and is part of
* standard reset sequence.
+ *
+ * Return: zero on success or appropriate error code.
*/
-static bool vmballoon_send_guest_id(struct vmballoon *b)
+static int vmballoon_send_guest_id(struct vmballoon *b)
{
- unsigned long status, dummy = 0;
-
- status = VMWARE_BALLOON_CMD(GUEST_ID, VMW_BALLOON_GUEST_ID, dummy,
- dummy);
-
- STATS_INC(b->stats.guest_type);
+ unsigned long status;
- if (vmballoon_check_status(b, status))
- return true;
+ status = vmballoon_cmd(b, VMW_BALLOON_CMD_GUEST_ID,
+ VMW_BALLOON_GUEST_ID, 0);
- pr_debug("%s - failed, hv returns %ld\n", __func__, status);
- STATS_INC(b->stats.guest_type_fail);
- return false;
+ return status == VMW_BALLOON_SUCCESS ? 0 : -EIO;
}
-static u16 vmballoon_page_size(bool is_2m_page)
+/**
+ * vmballoon_page_order() - return the order of the page
+ * @page_size: the size of the page.
+ *
+ * Return: the allocation order.
+ */
+static inline
+unsigned int vmballoon_page_order(enum vmballoon_page_size_type page_size)
{
- if (is_2m_page)
- return 1 << VMW_BALLOON_2M_SHIFT;
+ return page_size == VMW_BALLOON_2M_PAGE ? VMW_BALLOON_2M_ORDER : 0;
+}
- return 1;
+/**
+ * vmballoon_page_in_frames() - returns the number of frames in a page.
+ * @page_size: the size of the page.
+ *
+ * Return: the number of 4k frames.
+ */
+static inline unsigned int
+vmballoon_page_in_frames(enum vmballoon_page_size_type page_size)
+{
+ return 1 << vmballoon_page_order(page_size);
}
-/*
- * Retrieve desired balloon size from the host.
+/**
+ * vmballoon_send_get_target() - Retrieve desired balloon size from the host.
+ *
+ * @b: pointer to the balloon.
+ *
+ * Return: zero on success, EINVAL if limit does not fit in 32-bit, as required
+ * by the host-guest protocol and EIO if an error occurred in communicating with
+ * the host.
*/
-static bool vmballoon_send_get_target(struct vmballoon *b, u32 *new_target)
+static int vmballoon_send_get_target(struct vmballoon *b)
{
unsigned long status;
- unsigned long target;
unsigned long limit;
- unsigned long dummy = 0;
- u32 limit32;
- /*
- * si_meminfo() is cheap. Moreover, we want to provide dynamic
- * max balloon size later. So let us call si_meminfo() every
- * iteration.
- */
- si_meminfo(&b->sysinfo);
- limit = b->sysinfo.totalram;
+ limit = totalram_pages;
/* Ensure limit fits in 32-bits */
- limit32 = (u32)limit;
- if (limit != limit32)
- return false;
-
- /* update stats */
- STATS_INC(b->stats.target);
+ if (limit != (u32)limit)
+ return -EINVAL;
- status = VMWARE_BALLOON_CMD(GET_TARGET, limit, dummy, target);
- if (vmballoon_check_status(b, status)) {
- *new_target = target;
- return true;
- }
+ status = vmballoon_cmd(b, VMW_BALLOON_CMD_GET_TARGET, limit, 0);
- pr_debug("%s - failed, hv returns %ld\n", __func__, status);
- STATS_INC(b->stats.target_fail);
- return false;
+ return status == VMW_BALLOON_SUCCESS ? 0 : -EIO;
}
-/*
- * Notify the host about allocated page so that host can use it without
- * fear that guest will need it. Host may reject some pages, we need to
- * check the return value and maybe submit a different page.
+/**
+ * vmballoon_alloc_page_list - allocates a list of pages.
+ *
+ * @b: pointer to the balloon.
+ * @ctl: pointer for the %struct vmballoon_ctl, which defines the operation.
+ * @req_n_pages: the number of requested pages.
+ *
+ * Tries to allocate @req_n_pages. Add them to the list of balloon pages in
+ * @ctl.pages and updates @ctl.n_pages to reflect the number of pages.
+ *
+ * Return: zero on success or error code otherwise.
*/
-static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
- unsigned int *hv_status, unsigned int *target)
+static int vmballoon_alloc_page_list(struct vmballoon *b,
+ struct vmballoon_ctl *ctl,
+ unsigned int req_n_pages)
{
- unsigned long status, dummy = 0;
- u32 pfn32;
-
- pfn32 = (u32)pfn;
- if (pfn32 != pfn)
- return -EINVAL;
-
- STATS_INC(b->stats.lock[false]);
+ struct page *page;
+ unsigned int i;
- *hv_status = status = VMWARE_BALLOON_CMD(LOCK, pfn, dummy, *target);
- if (vmballoon_check_status(b, status))
- return 0;
+ for (i = 0; i < req_n_pages; i++) {
+ if (ctl->page_size == VMW_BALLOON_2M_PAGE)
+ page = alloc_pages(VMW_HUGE_PAGE_ALLOC_FLAGS,
+ VMW_BALLOON_2M_ORDER);
+ else
+ page = alloc_page(VMW_PAGE_ALLOC_FLAGS);
- pr_debug("%s - ppn %lx, hv returns %ld\n", __func__, pfn, status);
- STATS_INC(b->stats.lock_fail[false]);
- return -EIO;
-}
+ /* Update statistics */
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_ALLOC,
+ ctl->page_size);
-static int vmballoon_send_batched_lock(struct vmballoon *b,
- unsigned int num_pages, bool is_2m_pages, unsigned int *target)
-{
- unsigned long status;
- unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
+ if (page) {
+ /* Success. Add the page to the list and continue. */
+ list_add(&page->lru, &ctl->pages);
+ continue;
+ }
- STATS_INC(b->stats.lock[is_2m_pages]);
+ /* Allocation failed. Update statistics and stop. */
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_ALLOC_FAIL,
+ ctl->page_size);
+ break;
+ }
- if (is_2m_pages)
- status = VMWARE_BALLOON_CMD(BATCHED_2M_LOCK, pfn, num_pages,
- *target);
- else
- status = VMWARE_BALLOON_CMD(BATCHED_LOCK, pfn, num_pages,
- *target);
+ ctl->n_pages = i;
- if (vmballoon_check_status(b, status))
- return 0;
-
- pr_debug("%s - batch ppn %lx, hv returns %ld\n", __func__, pfn, status);
- STATS_INC(b->stats.lock_fail[is_2m_pages]);
- return 1;
+ return req_n_pages == ctl->n_pages ? 0 : -ENOMEM;
}
-/*
- * Notify the host that guest intends to release given page back into
- * the pool of available (to the guest) pages.
+/**
+ * vmballoon_handle_one_result - Handle lock/unlock result for a single page.
+ *
+ * @b: pointer for %struct vmballoon.
+ * @page: pointer for the page whose result should be handled.
+ * @page_size: size of the page.
+ * @status: status of the operation as provided by the hypervisor.
*/
-static bool vmballoon_send_unlock_page(struct vmballoon *b, unsigned long pfn,
- unsigned int *target)
+static int vmballoon_handle_one_result(struct vmballoon *b, struct page *page,
+ enum vmballoon_page_size_type page_size,
+ unsigned long status)
{
- unsigned long status, dummy = 0;
- u32 pfn32;
-
- pfn32 = (u32)pfn;
- if (pfn32 != pfn)
- return false;
+ /* On success do nothing. The page is already on the balloon list. */
+ if (likely(status == VMW_BALLOON_SUCCESS))
+ return 0;
- STATS_INC(b->stats.unlock[false]);
+ pr_debug("%s: failed comm pfn %lx status %lu page_size %s\n", __func__,
+ page_to_pfn(page), status,
+ vmballoon_page_size_names[page_size]);
- status = VMWARE_BALLOON_CMD(UNLOCK, pfn, dummy, *target);
- if (vmballoon_check_status(b, status))
- return true;
+ /* Error occurred */
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_REFUSED_ALLOC,
+ page_size);
- pr_debug("%s - ppn %lx, hv returns %ld\n", __func__, pfn, status);
- STATS_INC(b->stats.unlock_fail[false]);
- return false;
+ return -EIO;
}
-static bool vmballoon_send_batched_unlock(struct vmballoon *b,
- unsigned int num_pages, bool is_2m_pages, unsigned int *target)
+/**
+ * vmballoon_status_page - returns the status of (un)lock operation
+ *
+ * @b: pointer to the balloon.
+ * @idx: index for the page for which the operation is performed.
+ * @p: pointer to where the page struct is returned.
+ *
+ * Following a lock or unlock operation, returns the status of the operation for
+ * an individual page. Provides the page that the operation was performed on on
+ * the @page argument.
+ *
+ * Returns: The status of a lock or unlock operation for an individual page.
+ */
+static unsigned long vmballoon_status_page(struct vmballoon *b, int idx,
+ struct page **p)
{
- unsigned long status;
- unsigned long pfn = PHYS_PFN(virt_to_phys(b->batch_page));
-
- STATS_INC(b->stats.unlock[is_2m_pages]);
-
- if (is_2m_pages)
- status = VMWARE_BALLOON_CMD(BATCHED_2M_UNLOCK, pfn, num_pages,
- *target);
- else
- status = VMWARE_BALLOON_CMD(BATCHED_UNLOCK, pfn, num_pages,
- *target);
+ if (static_branch_likely(&vmw_balloon_batching)) {
+ /* batching mode */
+ *p = pfn_to_page(b->batch_page[idx].pfn);
+ return b->batch_page[idx].status;
+ }
- if (vmballoon_check_status(b, status))
- return true;
+ /* non-batching mode */
+ *p = b->page;
- pr_debug("%s - batch ppn %lx, hv returns %ld\n", __func__, pfn, status);
- STATS_INC(b->stats.unlock_fail[is_2m_pages]);
- return false;
+ /*
+ * If a failure occurs, the indication will be provided in the status
+ * of the entire operation, which is considered before the individual
+ * page status. So for non-batching mode, the indication is always of
+ * success.
+ */
+ return VMW_BALLOON_SUCCESS;
}
-static struct page *vmballoon_alloc_page(gfp_t flags, bool is_2m_page)
+/**
+ * vmballoon_lock_op - notifies the host about inflated/deflated pages.
+ * @b: pointer to the balloon.
+ * @num_pages: number of inflated/deflated pages.
+ * @page_size: size of the page.
+ * @op: the type of operation (lock or unlock).
+ *
+ * Notify the host about page(s) that were ballooned (or removed from the
+ * balloon) so that host can use it without fear that guest will need it (or
+ * stop using them since the VM does). Host may reject some pages, we need to
+ * check the return value and maybe submit a different page. The pages that are
+ * inflated/deflated are pointed by @b->page.
+ *
+ * Return: result as provided by the hypervisor.
+ */
+static unsigned long vmballoon_lock_op(struct vmballoon *b,
+ unsigned int num_pages,
+ enum vmballoon_page_size_type page_size,
+ enum vmballoon_op op)
{
- if (is_2m_page)
- return alloc_pages(flags, VMW_BALLOON_2M_SHIFT);
+ unsigned long cmd, pfn;
- return alloc_page(flags);
-}
+ lockdep_assert_held(&b->comm_lock);
-static void vmballoon_free_page(struct page *page, bool is_2m_page)
-{
- if (is_2m_page)
- __free_pages(page, VMW_BALLOON_2M_SHIFT);
- else
- __free_page(page);
+ if (static_branch_likely(&vmw_balloon_batching)) {
+ if (op == VMW_BALLOON_INFLATE)
+ cmd = page_size == VMW_BALLOON_2M_PAGE ?
+ VMW_BALLOON_CMD_BATCHED_2M_LOCK :
+ VMW_BALLOON_CMD_BATCHED_LOCK;
+ else
+ cmd = page_size == VMW_BALLOON_2M_PAGE ?
+ VMW_BALLOON_CMD_BATCHED_2M_UNLOCK :
+ VMW_BALLOON_CMD_BATCHED_UNLOCK;
+
+ pfn = PHYS_PFN(virt_to_phys(b->batch_page));
+ } else {
+ cmd = op == VMW_BALLOON_INFLATE ? VMW_BALLOON_CMD_LOCK :
+ VMW_BALLOON_CMD_UNLOCK;
+ pfn = page_to_pfn(b->page);
+
+ /* In non-batching mode, PFNs must fit in 32-bit */
+ if (unlikely(pfn != (u32)pfn))
+ return VMW_BALLOON_ERROR_PPN_INVALID;
+ }
+
+ return vmballoon_cmd(b, cmd, pfn, num_pages);
}
-/*
- * Quickly release all pages allocated for the balloon. This function is
- * called when host decides to "reset" balloon for one reason or another.
- * Unlike normal "deflate" we do not (shall not) notify host of the pages
- * being released.
+/**
+ * vmballoon_add_page - adds a page towards lock/unlock operation.
+ *
+ * @b: pointer to the balloon.
+ * @idx: index of the page to be ballooned in this batch.
+ * @p: pointer to the page that is about to be ballooned.
+ *
+ * Adds the page to be ballooned. Must be called while holding @comm_lock.
*/
-static void vmballoon_pop(struct vmballoon *b)
+static void vmballoon_add_page(struct vmballoon *b, unsigned int idx,
+ struct page *p)
{
- struct page *page, *next;
- unsigned is_2m_pages;
-
- for (is_2m_pages = 0; is_2m_pages < VMW_BALLOON_NUM_PAGE_SIZES;
- is_2m_pages++) {
- struct vmballoon_page_size *page_size =
- &b->page_sizes[is_2m_pages];
- u16 size_per_page = vmballoon_page_size(is_2m_pages);
-
- 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]);
- b->size -= size_per_page;
- cond_resched();
- }
- }
+ lockdep_assert_held(&b->comm_lock);
- /* Clearing the batch_page unconditionally has no adverse effect */
- free_page((unsigned long)b->batch_page);
- b->batch_page = NULL;
+ if (static_branch_likely(&vmw_balloon_batching))
+ b->batch_page[idx] = (struct vmballoon_batch_entry)
+ { .pfn = page_to_pfn(p) };
+ else
+ b->page = p;
}
-/*
- * Notify the host of a ballooned page. If host rejects the page put it on the
- * refuse list, those refused page are then released at the end of the
- * inflation cycle.
+/**
+ * vmballoon_lock - lock or unlock a batch of pages.
+ *
+ * @b: pointer to the balloon.
+ * @ctl: pointer for the %struct vmballoon_ctl, which defines the operation.
+ *
+ * Notifies the host of about ballooned pages (after inflation or deflation,
+ * according to @ctl). If the host rejects the page put it on the
+ * @ctl refuse list. These refused page are then released when moving to the
+ * next size of pages.
+ *
+ * Note that we neither free any @page here nor put them back on the ballooned
+ * pages list. Instead we queue it for later processing. We do that for several
+ * reasons. First, we do not want to free the page under the lock. Second, it
+ * allows us to unify the handling of lock and unlock. In the inflate case, the
+ * caller will check if there are too many refused pages and release them.
+ * Although it is not identical to the past behavior, it should not affect
+ * performance.
*/
-static int vmballoon_lock_page(struct vmballoon *b, unsigned int num_pages,
- bool is_2m_pages, unsigned int *target)
+static int vmballoon_lock(struct vmballoon *b, struct vmballoon_ctl *ctl)
{
- int locked, hv_status;
- struct page *page = b->page;
- struct vmballoon_page_size *page_size = &b->page_sizes[false];
-
- /* is_2m_pages can never happen as 2m pages support implies batching */
-
- locked = vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status,
- target);
- if (locked) {
- STATS_INC(b->stats.refused_alloc[false]);
-
- if (locked == -EIO &&
- (hv_status == VMW_BALLOON_ERROR_RESET ||
- hv_status == VMW_BALLOON_ERROR_PPN_NOTNEEDED)) {
- vmballoon_free_page(page, false);
- return -EIO;
- }
-
- /*
- * Place page on the list of non-balloonable pages
- * and retry allocation, unless we already accumulated
- * too many of them, in which case take a breather.
- */
- if (page_size->n_refused_pages < VMW_BALLOON_MAX_REFUSED) {
- page_size->n_refused_pages++;
- list_add(&page->lru, &page_size->refused_pages);
- } else {
- vmballoon_free_page(page, false);
- }
- return locked;
- }
-
- /* track allocated page */
- list_add(&page->lru, &page_size->pages);
+ unsigned long batch_status;
+ struct page *page;
+ unsigned int i, num_pages;
- /* update balloon size */
- b->size++;
+ num_pages = ctl->n_pages;
+ if (num_pages == 0)
+ return 0;
- return 0;
-}
+ /* communication with the host is done under the communication lock */
+ spin_lock(&b->comm_lock);
-static int vmballoon_lock_batched_page(struct vmballoon *b,
- unsigned int num_pages, bool is_2m_pages, unsigned int *target)
-{
- int locked, i;
- u16 size_per_page = vmballoon_page_size(is_2m_pages);
+ i = 0;
+ list_for_each_entry(page, &ctl->pages, lru)
+ vmballoon_add_page(b, i++, page);
- locked = vmballoon_send_batched_lock(b, num_pages, is_2m_pages,
- target);
- if (locked > 0) {
- for (i = 0; i < num_pages; i++) {
- u64 pa = vmballoon_batch_get_pa(b->batch_page, i);
- struct page *p = pfn_to_page(pa >> PAGE_SHIFT);
+ batch_status = vmballoon_lock_op(b, ctl->n_pages, ctl->page_size,
+ ctl->op);
- vmballoon_free_page(p, is_2m_pages);
- }
+ /*
+ * Iterate over the pages in the provided list. Since we are changing
+ * @ctl->n_pages we are saving the original value in @num_pages and
+ * use this value to bound the loop.
+ */
+ for (i = 0; i < num_pages; i++) {
+ unsigned long status;
- return -EIO;
- }
+ status = vmballoon_status_page(b, i, &page);
- for (i = 0; i < num_pages; i++) {
- u64 pa = vmballoon_batch_get_pa(b->batch_page, i);
- struct page *p = pfn_to_page(pa >> PAGE_SHIFT);
- struct vmballoon_page_size *page_size =
- &b->page_sizes[is_2m_pages];
+ /*
+ * Failure of the whole batch overrides a single operation
+ * results.
+ */
+ if (batch_status != VMW_BALLOON_SUCCESS)
+ status = batch_status;
- locked = vmballoon_batch_get_status(b->batch_page, i);
+ /* Continue if no error happened */
+ if (!vmballoon_handle_one_result(b, page, ctl->page_size,
+ status))
+ continue;
- switch (locked) {
- case VMW_BALLOON_SUCCESS:
- list_add(&p->lru, &page_size->pages);
- b->size += size_per_page;
- break;
- case VMW_BALLOON_ERROR_PPN_PINNED:
- case VMW_BALLOON_ERROR_PPN_INVALID:
- if (page_size->n_refused_pages
- < VMW_BALLOON_MAX_REFUSED) {
- list_add(&p->lru, &page_size->refused_pages);
- page_size->n_refused_pages++;
- break;
- }
- /* Fallthrough */
- case VMW_BALLOON_ERROR_RESET:
- case VMW_BALLOON_ERROR_PPN_NOTNEEDED:
- vmballoon_free_page(p, is_2m_pages);
- break;
- default:
- /* This should never happen */
- WARN_ON_ONCE(true);
- }
+ /*
+ * Error happened. Move the pages to the refused list and update
+ * the pages number.
+ */
+ list_move(&page->lru, &ctl->refused_pages);
+ ctl->n_pages--;
+ ctl->n_refused_pages++;
}
- return 0;
+ spin_unlock(&b->comm_lock);
+
+ return batch_status == VMW_BALLOON_SUCCESS ? 0 : -EIO;
}
-/*
- * Release the page allocated for the balloon. Note that we first notify
- * the host so it can make sure the page will be available for the guest
- * to use, if needed.
+/**
+ * vmballoon_release_page_list() - Releases a page list
+ *
+ * @page_list: list of pages to release.
+ * @n_pages: pointer to the number of pages.
+ * @page_size: whether the pages in the list are 2MB (or else 4KB).
+ *
+ * Releases the list of pages and zeros the number of pages.
*/
-static int vmballoon_unlock_page(struct vmballoon *b, unsigned int num_pages,
- bool is_2m_pages, unsigned int *target)
+static void vmballoon_release_page_list(struct list_head *page_list,
+ int *n_pages,
+ enum vmballoon_page_size_type page_size)
{
- struct page *page = b->page;
- struct vmballoon_page_size *page_size = &b->page_sizes[false];
-
- /* is_2m_pages can never happen as 2m pages support implies batching */
+ struct page *page, *tmp;
- if (!vmballoon_send_unlock_page(b, page_to_pfn(page), target)) {
- list_add(&page->lru, &page_size->pages);
- return -EIO;
+ list_for_each_entry_safe(page, tmp, page_list, lru) {
+ list_del(&page->lru);
+ __free_pages(page, vmballoon_page_order(page_size));
}
- /* deallocate page */
- vmballoon_free_page(page, false);
- STATS_INC(b->stats.free[false]);
+ *n_pages = 0;
+}
- /* update balloon size */
- b->size--;
- return 0;
+/*
+ * Release pages that were allocated while attempting to inflate the
+ * balloon but were refused by the host for one reason or another.
+ */
+static void vmballoon_release_refused_pages(struct vmballoon *b,
+ struct vmballoon_ctl *ctl)
+{
+ vmballoon_stats_page_inc(b, VMW_BALLOON_PAGE_STAT_REFUSED_FREE,
+ ctl->page_size);
+
+ vmballoon_release_page_list(&ctl->refused_pages, &ctl->n_refused_pages,
+ ctl->page_size);
}
-static int vmballoon_unlock_batched_page(struct vmballoon *b,
- unsigned int num_pages, bool is_2m_pages,
- unsigned int *target)
+/**
+ * vmballoon_change - retrieve the required balloon change
+ *
+ * @b: pointer for the balloon.
+ *
+ * Return: the required change for the balloon size. A positive number
+ * indicates inflation, a negative number indicates a deflation.
+ */
+static int64_t vmballoon_change(struct vmballoon *b)
{
- int locked, i, ret = 0;
- bool hv_success;
- u16 size_per_page = vmballoon_page_size(is_2m_pages);
+ int64_t size, target;
- hv_success = vmballoon_send_batched_unlock(b, num_pages, is_2m_pages,
- target);
- if (!hv_success)
- ret = -EIO;
+ size = atomic64_read(&b->size);
+ target = READ_ONCE(b->target);
- for (i = 0; i < num_pages; i++) {
- u64 pa = vmballoon_batch_get_pa(b->batch_page, i);
- struct page *p = pfn_to_page(pa >> PAGE_SHIFT);
- struct vmballoon_page_size *page_size =
- &b->page_sizes[is_2m_pages];
+ /*
+ * We must cast first because of int sizes
+ * Otherwise we might get huge positives instead of negatives
+ */
- locked = vmballoon_batch_get_status(b->batch_page, i);
- if (!hv_success || locked != VMW_BALLOON_SUCCESS) {
- /*
- * That page wasn't successfully unlocked by the
- * hypervisor, re-add it to the list of pages owned by
- * the balloon driver.
- */
- list_add(&p->lru, &page_size->pages);
- } else {
- /* deallocate page */
- vmballoon_free_page(p, is_2m_pages);
- STATS_INC(b->stats.free[is_2m_pages]);
-
- /* update balloon size */
- b->size -= size_per_page;
- }
- }
+ if (b->reset_required)
+ return 0;
+
+ /* consider a 2MB slack on deflate, unless the balloon is emptied */
+ if (target < size && target != 0 &&
+ size - target < vmballoon_page_in_frames(VMW_BALLOON_2M_PAGE))
+ return 0;
- return ret;
+ return target - size;
}
-/*
- * Release pages that were allocated while attempting to inflate the
- * balloon but were refused by the host for one reason or another.
+/**
+ * vmballoon_enqueue_page_list() - Enqueues list of pages after inflation.
+ *
+ * @b: pointer to balloon.
+ * @pages: list of pages to enqueue.
+ * @n_pages: pointer to number of pages in list. The value is zeroed.
+ * @page_size: whether the pages are 2MB or 4KB pages.
+ *
+ * Enqueues the provides list of pages in the ballooned page list, clears the
+ * list and zeroes the number of pages that was provided.
*/
-static void vmballoon_release_refused_pages(struct vmballoon *b,
- bool is_2m_pages)
+static void vmballoon_enqueue_page_list(struct vmballoon *b,
+ struct list_head *pages,
+ unsigned int *n_pages,
+ enum vmballoon_page_size_type page_size)
{
- struct page *page, *next;
- struct vmballoon_page_size *page_size =
- &b->page_sizes[is_2m_pages];
+ struct vmballoon_page_size *page_size_info = &b->page_sizes[page_size];
- 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]);
- }
-
- page_size->n_refused_pages = 0;
+ list_splice_init(pages, &page_size_info->pages);
+ *n_pages = 0;
}
-static void vmballoon_add_page(struct vmballoon *b, int idx, struct page *p)
+/**
+ * vmballoon_dequeue_page_list() - Dequeues page lists for deflation.
+ *
+ * @b: pointer to balloon.
+ * @pages: list of pages to enqueue.
+ * @n_pages: pointer to number of pages in list. The value is zeroed.
+ * @page_size: whether the pages are 2MB or 4KB pages.
+ * @n_req_pages: the number of requested pages.
+ *
+ * Dequeues the number of requested pages from the balloon for deflation. The
+ * number of dequeued pages may be lower, if not enough pages in the requested
+ * size are available.
+ */
+static void vmballoon_dequeue_page_list(struct vmballoon *b,
+ struct list_head *pages,
+ unsigned int *n_pages,
+ enum vmballoon_page_size_type page_size,
+ unsigned int n_req_pages)
{
- b->page = p;
-}
+ struct vmballoon_page_size *page_size_info = &b->page_sizes[page_size];
+ struct page *page, *tmp;
+ unsigned int i = 0;
-static void vmballoon_add_batched_page(struct vmballoon *b, int idx,
- struct page *p)
-{
- vmballoon_batch_set_pa(b->batch_page, idx,
- (u64)page_to_pfn(p) << PAGE_SHIFT);
+ list_for_each_entry_safe(page, tmp, &page_size_info->pages, lru) {
+ list_move(&page->lru, pages);
+ if (++i == n_req_pages)
+ break;
+ }
+ *n_pages = i;
}
-/*
- * Inflate the balloon towards its target size. Note that we try to limit
- * the rate of allocation to make sure we are not choking the rest of the
- * system.
+/**
+ * vmballoon_inflate() - Inflate the balloon towards its target size.
+ *
+ * @b: pointer to the balloon.
*/
static void vmballoon_inflate(struct vmballoon *b)
{
- unsigned int num_pages = 0;
- int error = 0;
- gfp_t flags = VMW_PAGE_ALLOC_NOSLEEP;
- bool is_2m_pages;
+ int64_t to_inflate_frames;
+ struct vmballoon_ctl ctl = {
+ .pages = LIST_HEAD_INIT(ctl.pages),
+ .refused_pages = LIST_HEAD_INIT(ctl.refused_pages),
+ .page_size = b->max_page_size,
+ .op = VMW_BALLOON_INFLATE
+ };
- pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target);
+ while ((to_inflate_frames = vmballoon_change(b)) > 0) {
+ unsigned int to_inflate_pages, page_in_frames;
+ int alloc_error, lock_error = 0;
- /*
- * First try NOSLEEP page allocations to inflate balloon.
- *
- * If we do not throttle nosleep allocations, we can drain all
- * free pages in the guest quickly (if the balloon target is high).
- * As a side-effect, draining free pages helps to inform (force)
- * the guest to start swapping if balloon target is not met yet,
- * which is a desired behavior. However, balloon driver can consume
- * all available CPU cycles if too many pages are allocated in a
- * second. Therefore, we throttle nosleep allocations even when
- * the guest is not under memory pressure. OTOH, if we have already
- * predicted that the guest is under memory pressure, then we
- * slowdown page allocations considerably.
- */
+ VM_BUG_ON(!list_empty(&ctl.pages));
+ VM_BUG_ON(ctl.n_pages != 0);
- /*
- * Start with no sleep allocation rate which may be higher
- * than sleeping allocation rate.
- */
- is_2m_pages = b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES;
+ page_in_frames = vmballoon_page_in_frames(ctl.page_size);
- pr_debug("%s - goal: %d", __func__, b->target - b->size);
+ to_inflate_pages = min_t(unsigned long, b->batch_max_pages,
+ DIV_ROUND_UP_ULL(to_inflate_frames,
+ page_in_frames));
- while (!b->reset_required &&
- b->size + num_pages * vmballoon_page_size(is_2m_pages)
- < b->target) {
- struct page *page;
+ /* Start by allocating */
+ alloc_error = vmballoon_alloc_page_list(b, &ctl,
+ to_inflate_pages);
- if (flags == VMW_PAGE_ALLOC_NOSLEEP)
- STATS_INC(b->stats.alloc[is_2m_pages]);
- else
- STATS_INC(b->stats.sleep_alloc);
-
- page = vmballoon_alloc_page(flags, is_2m_pages);
- if (!page) {
- STATS_INC(b->stats.alloc_fail[is_2m_pages]);
-
- if (is_2m_pages) {
- b->ops->lock(b, num_pages, true, &b->target);
-
- /*
- * ignore errors from locking as we now switch
- * to 4k pages and we might get different
- * errors.
- */
-
- num_pages = 0;
- is_2m_pages = false;
- continue;
- }
-
- if (flags == VMW_PAGE_ALLOC_CANSLEEP) {
- /*
- * CANSLEEP page allocation failed, so guest
- * is under severe memory pressure. We just log
- * the event, but do not stop the inflation
- * due to its negative impact on performance.
- */
- STATS_INC(b->stats.sleep_alloc_fail);
+ /* Actually lock the pages by telling the hypervisor */
+ lock_error = vmballoon_lock(b, &ctl);
+
+ /*
+ * If an error indicates that something serious went wrong,
+ * stop the inflation.
+ */
+ if (lock_error)
+ break;
+
+ /* Update the balloon size */
+ atomic64_add(ctl.n_pages * page_in_frames, &b->size);
+
+ vmballoon_enqueue_page_list(b, &ctl.pages, &ctl.n_pages,
+ ctl.page_size);
+
+ /*
+ * If allocation failed or the number of refused pages exceeds
+ * the maximum allowed, move to the next page size.
+ */
+ if (alloc_error ||
+ ctl.n_refused_pages >= VMW_BALLOON_MAX_REFUSED) {
+ if (ctl.page_size == VMW_BALLOON_4K_PAGE)
break;
- }
/*
- * NOSLEEP page allocation failed, so the guest is
- * under memory pressure. Slowing down page alloctions
- * seems to be reasonable, but doing so might actually
- * cause the hypervisor to throttle us down, resulting
- * in degraded performance. We will count on the
- * scheduler and standard memory management mechanisms
- * for now.
+ * Ignore errors from locking as we now switch to 4k
+ * pages and we might get different errors.
*/
- flags = VMW_PAGE_ALLOC_CANSLEEP;
- continue;
- }
-
- b->ops->add_page(b, num_pages++, page);
- if (num_pages == b->batch_max_pages) {
- error = b->ops->lock(b, num_pages, is_2m_pages,
- &b->target);
- num_pages = 0;
- if (error)
- break;
+ vmballoon_release_refused_pages(b, &ctl);
+ ctl.page_size--;
}
cond_resched();
}
- if (num_pages > 0)
- b->ops->lock(b, num_pages, is_2m_pages, &b->target);
-
- vmballoon_release_refused_pages(b, true);
- vmballoon_release_refused_pages(b, false);
+ /*
+ * Release pages that were allocated while attempting to inflate the
+ * balloon but were refused by the host for one reason or another,
+ * and update the statistics.
+ */
+ if (ctl.n_refused_pages != 0)
+ vmballoon_release_refused_pages(b, &ctl);
}
-/*
+/**
+ * vmballoon_deflate() - Decrease the size of the balloon.
+ *
+ * @b: pointer to the balloon
+ * @n_frames: the number of frames to deflate. If zero, automatically
+ * calculated according to the target size.
+ * @coordinated: whether to coordinate with the host
+ *
* Decrease the size of the balloon allowing guest to use more memory.
+ *
+ * Return: The number of deflated frames (i.e., basic page size units)
*/
-static void vmballoon_deflate(struct vmballoon *b)
+static unsigned long vmballoon_deflate(struct vmballoon *b, uint64_t n_frames,
+ bool coordinated)
{
- unsigned is_2m_pages;
-
- pr_debug("%s - size: %d, target %d\n", __func__, b->size, b->target);
+ unsigned long deflated_frames = 0;
+ unsigned long tried_frames = 0;
+ struct vmballoon_ctl ctl = {
+ .pages = LIST_HEAD_INIT(ctl.pages),
+ .refused_pages = LIST_HEAD_INIT(ctl.refused_pages),
+ .page_size = VMW_BALLOON_4K_PAGE,
+ .op = VMW_BALLOON_DEFLATE
+ };
/* free pages to reach target */
- for (is_2m_pages = 0; is_2m_pages < b->supported_page_sizes;
- is_2m_pages++) {
- struct page *page, *next;
- unsigned int num_pages = 0;
- struct vmballoon_page_size *page_size =
- &b->page_sizes[is_2m_pages];
-
- list_for_each_entry_safe(page, next, &page_size->pages, lru) {
- if (b->reset_required ||
- (b->target > 0 &&
- b->size - num_pages
- * vmballoon_page_size(is_2m_pages)
- < b->target + vmballoon_page_size(true)))
- break;
+ while (true) {
+ unsigned int to_deflate_pages, n_unlocked_frames;
+ unsigned int page_in_frames;
+ int64_t to_deflate_frames;
+ bool deflated_all;
+
+ page_in_frames = vmballoon_page_in_frames(ctl.page_size);
+
+ VM_BUG_ON(!list_empty(&ctl.pages));
+ VM_BUG_ON(ctl.n_pages);
+ VM_BUG_ON(!list_empty(&ctl.refused_pages));
+ VM_BUG_ON(ctl.n_refused_pages);
+
+ /*
+ * If we were requested a specific number of frames, we try to
+ * deflate this number of frames. Otherwise, deflation is
+ * performed according to the target and balloon size.
+ */
+ to_deflate_frames = n_frames ? n_frames - tried_frames :
+ -vmballoon_change(b);
+
+ /* break if no work to do */
+ if (to_deflate_frames <= 0)
+ break;
+
+ /*
+ * Calculate the number of frames based on current page size,
+ * but limit the deflated frames to a single chunk
+ */
+ to_deflate_pages = min_t(unsigned long, b->batch_max_pages,
+ DIV_ROUND_UP_ULL(to_deflate_frames,
+ page_in_frames));
+
+ /* First take the pages from the balloon pages. */
+ vmballoon_dequeue_page_list(b, &ctl.pages, &ctl.n_pages,
+ ctl.page_size, to_deflate_pages);
+
+ /*
+ * Before pages are moving to the refused list, count their
+ * frames as frames that we tried to deflate.
+ */
+ tried_frames += ctl.n_pages * page_in_frames;
+
+ /*
+ * Unlock the pages by communicating with the hypervisor if the
+ * communication is coordinated (i.e., not pop). We ignore the
+ * return code. Instead we check if all the pages we manage to
+ * unlock all the pages. If we failed, we will move to the next
+ * page size, and would eventually try again later.
+ */
+ if (coordinated)
+ vmballoon_lock(b, &ctl);
+
+ /*
+ * Check if we deflated enough. We will move to the next page
+ * size if we did not manage to do so. This calculation takes
+ * place now, as once the pages are released, the number of
+ * pages is zeroed.
+ */
+ deflated_all = (ctl.n_pages == to_deflate_pages);
+
+ /* Update local and global counters */
+ n_unlocked_frames = ctl.n_pages * page_in_frames;
+ atomic64_sub(n_unlocked_frames, &b->size);
+ deflated_frames += n_unlocked_frames;
- list_del(&page->lru);
- b->ops->add_page(b, num_pages++, page);
+ vmballoon_stats_page_add(b, VMW_BALLOON_PAGE_STAT_FREE,
+ ctl.page_size, ctl.n_pages);
- if (num_pages == b->batch_max_pages) {
- int error;
+ /* free the ballooned pages */
+ vmballoon_release_page_list(&ctl.pages, &ctl.n_pages,
+ ctl.page_size);
- error = b->ops->unlock(b, num_pages,
- is_2m_pages, &b->target);
- num_pages = 0;
- if (error)
- return;
- }
+ /* Return the refused pages to the ballooned list. */
+ vmballoon_enqueue_page_list(b, &ctl.refused_pages,
+ &ctl.n_refused_pages,
+ ctl.page_size);
- cond_resched();
+ /* If we failed to unlock all the pages, move to next size. */
+ if (!deflated_all) {
+ if (ctl.page_size == b->max_page_size)
+ break;
+ ctl.page_size++;
}
- if (num_pages > 0)
- b->ops->unlock(b, num_pages, is_2m_pages, &b->target);
+ cond_resched();
}
-}
-static const struct vmballoon_ops vmballoon_basic_ops = {
- .add_page = vmballoon_add_page,
- .lock = vmballoon_lock_page,
- .unlock = vmballoon_unlock_page
-};
+ return deflated_frames;
+}
-static const struct vmballoon_ops vmballoon_batched_ops = {
- .add_page = vmballoon_add_batched_page,
- .lock = vmballoon_lock_batched_page,
- .unlock = vmballoon_unlock_batched_page
-};
+/**
+ * vmballoon_deinit_batching - disables batching mode.
+ *
+ * @b: pointer to &struct vmballoon.
+ *
+ * Disables batching, by deallocating the page for communication with the
+ * hypervisor and disabling the static key to indicate that batching is off.
+ */
+static void vmballoon_deinit_batching(struct vmballoon *b)
+{
+ free_page((unsigned long)b->batch_page);
+ b->batch_page = NULL;
+ static_branch_disable(&vmw_balloon_batching);
+ b->batch_max_pages = 1;
+}
-static bool vmballoon_init_batching(struct vmballoon *b)
+/**
+ * vmballoon_init_batching - enable batching mode.
+ *
+ * @b: pointer to &struct vmballoon.
+ *
+ * Enables batching, by allocating a page for communication with the hypervisor
+ * and enabling the static_key to use batching.
+ *
+ * Return: zero on success or an appropriate error-code.
+ */
+static int vmballoon_init_batching(struct vmballoon *b)
{
struct page *page;
page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!page)
- return false;
+ return -ENOMEM;
b->batch_page = page_address(page);
- return true;
+ b->batch_max_pages = PAGE_SIZE / sizeof(struct vmballoon_batch_entry);
+
+ static_branch_enable(&vmw_balloon_batching);
+
+ return 0;
}
/*
{
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);
}
*/
static void vmballoon_vmci_cleanup(struct vmballoon *b)
{
- int error;
-
- VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET, VMCI_INVALID_ID,
- VMCI_INVALID_ID, error);
- STATS_INC(b->stats.doorbell_unset);
+ vmballoon_cmd(b, VMW_BALLOON_CMD_VMCI_DOORBELL_SET,
+ VMCI_INVALID_ID, VMCI_INVALID_ID);
if (!vmci_handle_is_invalid(b->vmci_doorbell)) {
vmci_doorbell_destroy(b->vmci_doorbell);
}
}
-/*
- * Initialize vmci doorbell, to get notified as soon as balloon changes
+/**
+ * vmballoon_vmci_init - Initialize vmci doorbell.
+ *
+ * @b: pointer to the balloon.
+ *
+ * Return: zero on success or when wakeup command not supported. Error-code
+ * otherwise.
+ *
+ * Initialize vmci doorbell, to get notified as soon as balloon changes.
*/
static int vmballoon_vmci_init(struct vmballoon *b)
{
- unsigned long error, dummy;
+ unsigned long error;
if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) == 0)
return 0;
if (error != VMCI_SUCCESS)
goto fail;
- error = VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET, b->vmci_doorbell.context,
- b->vmci_doorbell.resource, dummy);
-
- STATS_INC(b->stats.doorbell_set);
+ error = __vmballoon_cmd(b, VMW_BALLOON_CMD_VMCI_DOORBELL_SET,
+ b->vmci_doorbell.context,
+ b->vmci_doorbell.resource, NULL);
if (error != VMW_BALLOON_SUCCESS)
goto fail;
return -EIO;
}
+/**
+ * vmballoon_pop - Quickly release all pages allocate for the balloon.
+ *
+ * @b: pointer to the balloon.
+ *
+ * This function is called when host decides to "reset" balloon for one reason
+ * or another. Unlike normal "deflate" we do not (shall not) notify host of the
+ * pages being released.
+ */
+static void vmballoon_pop(struct vmballoon *b)
+{
+ unsigned long size;
+
+ while ((size = atomic64_read(&b->size)))
+ vmballoon_deflate(b, size, false);
+}
+
/*
* Perform standard reset sequence by popping the balloon (in case it
* is not empty) and then restarting protocol. This operation normally
{
int error;
+ down_write(&b->conf_sem);
+
vmballoon_vmci_cleanup(b);
/* free all pages, skipping monitor unlock */
vmballoon_pop(b);
- if (!vmballoon_send_start(b, VMW_BALLOON_CAPABILITIES))
+ if (vmballoon_send_start(b, VMW_BALLOON_CAPABILITIES))
return;
if ((b->capabilities & VMW_BALLOON_BATCHED_CMDS) != 0) {
- b->ops = &vmballoon_batched_ops;
- b->batch_max_pages = VMW_BALLOON_BATCH_MAX_PAGES;
- if (!vmballoon_init_batching(b)) {
+ if (vmballoon_init_batching(b)) {
/*
* We failed to initialize batching, inform the monitor
* about it by sending a null capability.
return;
}
} else if ((b->capabilities & VMW_BALLOON_BASIC_CMDS) != 0) {
- b->ops = &vmballoon_basic_ops;
- b->batch_max_pages = 1;
+ vmballoon_deinit_batching(b);
}
+ vmballoon_stats_gen_inc(b, VMW_BALLOON_STAT_RESET);
b->reset_required = false;
error = vmballoon_vmci_init(b);
if (error)
pr_err("failed to initialize vmci doorbell\n");
- if (!vmballoon_send_guest_id(b))
+ if (vmballoon_send_guest_id(b))
pr_err("failed to send guest ID to the host\n");
+
+ up_write(&b->conf_sem);
}
-/*
- * Balloon work function: reset protocol, if needed, get the new size and
- * adjust balloon as needed. Repeat in 1 sec.
+/**
+ * vmballoon_work - periodic balloon worker for reset, inflation and deflation.
+ *
+ * @work: pointer to the &work_struct which is provided by the workqueue.
+ *
+ * Resets the protocol if needed, gets the new size and adjusts balloon as
+ * needed. Repeat in 1 sec.
*/
static void vmballoon_work(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct vmballoon *b = container_of(dwork, struct vmballoon, dwork);
- unsigned int target;
-
- STATS_INC(b->stats.timer);
+ int64_t change = 0;
if (b->reset_required)
vmballoon_reset(b);
- if (!b->reset_required && vmballoon_send_get_target(b, &target)) {
- /* update target, adjust size */
- b->target = target;
+ 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);
+
+ if (change != 0) {
+ pr_debug("%s - size: %llu, target %lu\n", __func__,
+ atomic64_read(&b->size), READ_ONCE(b->target));
- if (b->size < target)
+ if (change > 0)
vmballoon_inflate(b);
- else if (target == 0 ||
- b->size > target + vmballoon_page_size(true))
- vmballoon_deflate(b);
+ else /* (change < 0) */
+ vmballoon_deflate(b, 0, true);
}
+ 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));
+
}
/*
*/
#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",
+ [VMW_BALLOON_STAT_RESET] = "reset",
+};
+
+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, 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: %#16x\n", "balloon capabilities",
+ VMW_BALLOON_CAPABILITIES);
+ seq_printf(f, "%-22s: %#16lx\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,
- "\n"
- "timer: %8u\n"
- "doorbell: %8u\n"
- "start: %8u (%4u failed)\n"
- "guestType: %8u (%4u failed)\n"
- "2m-lock: %8u (%4u failed)\n"
- "lock: %8u (%4u failed)\n"
- "2m-unlock: %8u (%4u failed)\n"
- "unlock: %8u (%4u failed)\n"
- "target: %8u (%4u failed)\n"
- "prim2mAlloc: %8u (%4u failed)\n"
- "primNoSleepAlloc: %8u (%4u failed)\n"
- "primCanSleepAlloc: %8u (%4u failed)\n"
- "prim2mFree: %8u\n"
- "primFree: %8u\n"
- "err2mAlloc: %8u\n"
- "errAlloc: %8u\n"
- "err2mFree: %8u\n"
- "errFree: %8u\n"
- "doorbellSet: %8u\n"
- "doorbellUnset: %8u\n",
- stats->timer,
- stats->doorbell,
- stats->start, stats->start_fail,
- stats->guest_type, stats->guest_type_fail,
- stats->lock[true], stats->lock_fail[true],
- stats->lock[false], stats->lock_fail[false],
- stats->unlock[true], stats->unlock_fail[true],
- stats->unlock[false], stats->unlock_fail[false],
- stats->target, stats->target_fail,
- stats->alloc[true], stats->alloc_fail[true],
- stats->alloc[false], stats->alloc_fail[false],
- stats->sleep_alloc, stats->sleep_alloc_fail,
- stats->free[true],
- stats->free[false],
- stats->refused_alloc[true], stats->refused_alloc[false],
- stats->refused_free[true], stats->refused_free[false],
- stats->doorbell_set, stats->doorbell_unset);
+ seq_printf(f, "%-22s: %16lu\n", "target", READ_ONCE(b->target));
+ seq_printf(f, "%-22s: %16llu\n", "current", atomic64_read(&b->size));
+
+ for (i = 0; i < VMW_BALLOON_CMD_NUM; i++) {
+ if (vmballoon_cmd_names[i] == NULL)
+ continue;
+
+ 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]));
+ }
+
+ 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;
}
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
static int __init vmballoon_init(void)
{
+ enum vmballoon_page_size_type page_size;
int error;
- unsigned is_2m_pages;
+
/*
* Check if we are running on VMware's hypervisor and bail out
* if we are not.
if (x86_hyper_type != X86_HYPER_VMWARE)
return -ENODEV;
- for (is_2m_pages = 0; is_2m_pages < VMW_BALLOON_NUM_PAGE_SIZES;
- is_2m_pages++) {
- INIT_LIST_HEAD(&balloon.page_sizes[is_2m_pages].pages);
- INIT_LIST_HEAD(&balloon.page_sizes[is_2m_pages].refused_pages);
- }
+ for (page_size = VMW_BALLOON_4K_PAGE;
+ page_size <= VMW_BALLOON_LAST_SIZE; page_size++)
+ INIT_LIST_HEAD(&balloon.page_sizes[page_size].pages);
+
INIT_DELAYED_WORK(&balloon.dwork, vmballoon_work);
if (error)
return error;
+ spin_lock_init(&balloon.comm_lock);
+ init_rwsem(&balloon.conf_sem);
balloon.vmci_doorbell = VMCI_INVALID_HANDLE;
balloon.batch_page = NULL;
balloon.page = NULL;
projects / linux.git / blobdiff