qemu/migration/multifd.h
Hao Xiang 303e6f54f9 migration/multifd: Implement zero page transmission on the multifd thread.
1. Add zero_pages field in MultiFDPacket_t.
2. Implements the zero page detection and handling on the multifd
threads for non-compression, zlib and zstd compression backends.
3. Added a new value 'multifd' in ZeroPageDetection enumeration.
4. Adds zero page counters and updates multifd send/receive tracing
format to track the newly added counters.

Signed-off-by: Hao Xiang <hao.xiang@bytedance.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240311180015.3359271-5-hao.xiang@linux.dev
Signed-off-by: Peter Xu <peterx@redhat.com>
2024-03-11 16:57:09 -04:00

256 lines
7.3 KiB
C

/*
* Multifd common functions
*
* Copyright (c) 2019-2020 Red Hat Inc
*
* Authors:
* Juan Quintela <quintela@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef QEMU_MIGRATION_MULTIFD_H
#define QEMU_MIGRATION_MULTIFD_H
#include "ram.h"
typedef struct MultiFDRecvData MultiFDRecvData;
bool multifd_send_setup(void);
void multifd_send_shutdown(void);
void multifd_send_channel_created(void);
int multifd_recv_setup(Error **errp);
void multifd_recv_cleanup(void);
void multifd_recv_shutdown(void);
bool multifd_recv_all_channels_created(void);
void multifd_recv_new_channel(QIOChannel *ioc, Error **errp);
void multifd_recv_sync_main(void);
int multifd_send_sync_main(void);
bool multifd_queue_page(RAMBlock *block, ram_addr_t offset);
bool multifd_recv(void);
MultiFDRecvData *multifd_get_recv_data(void);
/* Multifd Compression flags */
#define MULTIFD_FLAG_SYNC (1 << 0)
/* We reserve 3 bits for compression methods */
#define MULTIFD_FLAG_COMPRESSION_MASK (7 << 1)
/* we need to be compatible. Before compression value was 0 */
#define MULTIFD_FLAG_NOCOMP (0 << 1)
#define MULTIFD_FLAG_ZLIB (1 << 1)
#define MULTIFD_FLAG_ZSTD (2 << 1)
/* This value needs to be a multiple of qemu_target_page_size() */
#define MULTIFD_PACKET_SIZE (512 * 1024)
typedef struct {
uint32_t magic;
uint32_t version;
uint32_t flags;
/* maximum number of allocated pages */
uint32_t pages_alloc;
/* non zero pages */
uint32_t normal_pages;
/* size of the next packet that contains pages */
uint32_t next_packet_size;
uint64_t packet_num;
/* zero pages */
uint32_t zero_pages;
uint32_t unused32[1]; /* Reserved for future use */
uint64_t unused64[3]; /* Reserved for future use */
char ramblock[256];
/*
* This array contains the pointers to:
* - normal pages (initial normal_pages entries)
* - zero pages (following zero_pages entries)
*/
uint64_t offset[];
} __attribute__((packed)) MultiFDPacket_t;
typedef struct {
/* number of used pages */
uint32_t num;
/* number of normal pages */
uint32_t normal_num;
/* number of allocated pages */
uint32_t allocated;
/* offset of each page */
ram_addr_t *offset;
RAMBlock *block;
} MultiFDPages_t;
struct MultiFDRecvData {
void *opaque;
size_t size;
/* for preadv */
off_t file_offset;
};
typedef struct {
/* Fields are only written at creating/deletion time */
/* No lock required for them, they are read only */
/* channel number */
uint8_t id;
/* channel thread name */
char *name;
/* channel thread id */
QemuThread thread;
bool thread_created;
QemuThread tls_thread;
bool tls_thread_created;
/* communication channel */
QIOChannel *c;
/* packet allocated len */
uint32_t packet_len;
/* guest page size */
uint32_t page_size;
/* number of pages in a full packet */
uint32_t page_count;
/* multifd flags for sending ram */
int write_flags;
/* sem where to wait for more work */
QemuSemaphore sem;
/* syncs main thread and channels */
QemuSemaphore sem_sync;
/* multifd flags for each packet */
uint32_t flags;
/*
* The sender thread has work to do if either of below boolean is set.
*
* @pending_job: a job is pending
* @pending_sync: a sync request is pending
*
* For both of these fields, they're only set by the requesters, and
* cleared by the multifd sender threads.
*/
bool pending_job;
bool pending_sync;
/* array of pages to sent.
* The owner of 'pages' depends of 'pending_job' value:
* pending_job == 0 -> migration_thread can use it.
* pending_job != 0 -> multifd_channel can use it.
*/
MultiFDPages_t *pages;
/* thread local variables. No locking required */
/* pointer to the packet */
MultiFDPacket_t *packet;
/* size of the next packet that contains pages */
uint32_t next_packet_size;
/* packets sent through this channel */
uint64_t packets_sent;
/* non zero pages sent through this channel */
uint64_t total_normal_pages;
/* zero pages sent through this channel */
uint64_t total_zero_pages;
/* buffers to send */
struct iovec *iov;
/* number of iovs used */
uint32_t iovs_num;
/* used for compression methods */
void *compress_data;
} MultiFDSendParams;
typedef struct {
/* Fields are only written at creating/deletion time */
/* No lock required for them, they are read only */
/* channel number */
uint8_t id;
/* channel thread name */
char *name;
/* channel thread id */
QemuThread thread;
bool thread_created;
/* communication channel */
QIOChannel *c;
/* packet allocated len */
uint32_t packet_len;
/* guest page size */
uint32_t page_size;
/* number of pages in a full packet */
uint32_t page_count;
/* syncs main thread and channels */
QemuSemaphore sem_sync;
/* sem where to wait for more work */
QemuSemaphore sem;
/* this mutex protects the following parameters */
QemuMutex mutex;
/* should this thread finish */
bool quit;
/* multifd flags for each packet */
uint32_t flags;
/* global number of generated multifd packets */
uint64_t packet_num;
int pending_job;
MultiFDRecvData *data;
/* thread local variables. No locking required */
/* pointer to the packet */
MultiFDPacket_t *packet;
/* size of the next packet that contains pages */
uint32_t next_packet_size;
/* packets received through this channel */
uint64_t packets_recved;
/* ramblock */
RAMBlock *block;
/* ramblock host address */
uint8_t *host;
/* non zero pages recv through this channel */
uint64_t total_normal_pages;
/* zero pages recv through this channel */
uint64_t total_zero_pages;
/* buffers to recv */
struct iovec *iov;
/* Pages that are not zero */
ram_addr_t *normal;
/* num of non zero pages */
uint32_t normal_num;
/* Pages that are zero */
ram_addr_t *zero;
/* num of zero pages */
uint32_t zero_num;
/* used for de-compression methods */
void *compress_data;
} MultiFDRecvParams;
typedef struct {
/* Setup for sending side */
int (*send_setup)(MultiFDSendParams *p, Error **errp);
/* Cleanup for sending side */
void (*send_cleanup)(MultiFDSendParams *p, Error **errp);
/* Prepare the send packet */
int (*send_prepare)(MultiFDSendParams *p, Error **errp);
/* Setup for receiving side */
int (*recv_setup)(MultiFDRecvParams *p, Error **errp);
/* Cleanup for receiving side */
void (*recv_cleanup)(MultiFDRecvParams *p);
/* Read all data */
int (*recv)(MultiFDRecvParams *p, Error **errp);
} MultiFDMethods;
void multifd_register_ops(int method, MultiFDMethods *ops);
void multifd_send_fill_packet(MultiFDSendParams *p);
bool multifd_send_prepare_common(MultiFDSendParams *p);
void multifd_send_zero_page_detect(MultiFDSendParams *p);
void multifd_recv_zero_page_process(MultiFDRecvParams *p);
static inline void multifd_send_prepare_header(MultiFDSendParams *p)
{
p->iov[0].iov_len = p->packet_len;
p->iov[0].iov_base = p->packet;
p->iovs_num++;
}
void multifd_channel_connect(MultiFDSendParams *p, QIOChannel *ioc);
#endif