Commit 9e1ba4cc authored by Orit Wasserman's avatar Orit Wasserman Committed by Juan Quintela
Browse files

Add migrate_set_cache_size command 



Change XBZRLE cache size in bytes (the size should be a power of 2, it will be
rounded down to the nearest power of 2).
If XBZRLE cache size is too small there will be many cache miss.

New query-migrate-cache-size QMP command and 'info migrate_cache_size' HMP
command to query cache value.

Signed-off-by: default avatarBenoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: default avatarPetter Svard <petters@cs.umu.se>
Signed-off-by: default avatarAidan Shribman <aidan.shribman@sap.com>
Signed-off-by: default avatarOrit Wasserman <owasserm@redhat.com>

Reviewed-by: default avatarLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
parent 17ad9b35

arch_init.c

+10 −0
Original line number Diff line number Diff line
@@ -191,6 +191,16 @@ static struct { 
    .cache = NULL,

};





int64_t xbzrle_cache_resize(int64_t new_size)

{

    if (XBZRLE.cache != NULL) {

        return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *

            TARGET_PAGE_SIZE;

    }

    return pow2floor(new_size);

}



static void save_block_hdr(QEMUFile *f, RAMBlock *block, ram_addr_t offset,

        int cont, int flag)

{

hmp-commands.hx

+22 −0
Original line number Diff line number Diff line
@@ -829,6 +829,26 @@ STEXI 
@item migrate_cancel

@findex migrate_cancel

Cancel the current VM migration.



ETEXI



    {

        .name       = "migrate_set_cache_size",

        .args_type  = "value:o",

        .params     = "value",

        .help       = "set cache size (in bytes) for XBZRLE migrations,"

                      "the cache size will be rounded down to the nearest "

                      "power of 2.\n"

                      "The cache size affects the number of cache misses."

                      "In case of a high cache miss ratio you need to increase"

                      " the cache size",

        .mhandler.cmd = hmp_migrate_set_cache_size,

    },



STEXI

@item migrate_set_cache_size @var{value}

@findex migrate_set_cache_size

Set cache size to @var{value} (in bytes) for xbzrle migrations.

ETEXI



    {
@@ -1433,6 +1453,8 @@ show user network stack connection states 
show migration status

@item info migrate_capabilities

show current migration capabilities

@item info migrate_cache_size

show current migration XBZRLE cache size

@item info balloon

show balloon information

@item info qtree

hmp.c

+19 −0
Original line number Diff line number Diff line
@@ -194,6 +194,12 @@ void hmp_info_migrate_capabilities(Monitor *mon) 
    qapi_free_MigrationCapabilityStatusList(caps);

}



void hmp_info_migrate_cache_size(Monitor *mon)

{

    monitor_printf(mon, "xbzrel cache size: %" PRId64 " kbytes\n",

                   qmp_query_migrate_cache_size(NULL) >> 10);

}



void hmp_info_cpus(Monitor *mon)

{

    CpuInfoList *cpu_list, *cpu;
@@ -764,6 +770,19 @@ void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict) 
    qmp_migrate_set_downtime(value, NULL);

}



void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict)

{

    int64_t value = qdict_get_int(qdict, "value");

    Error *err = NULL;



    qmp_migrate_set_cache_size(value, &err);

    if (err) {

        monitor_printf(mon, "%s\n", error_get_pretty(err));

        error_free(err);

        return;

    }

}



void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)

{

    int64_t value = qdict_get_int(qdict, "value");

hmp.h

+2 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ void hmp_info_chardev(Monitor *mon); 
void hmp_info_mice(Monitor *mon);

void hmp_info_migrate(Monitor *mon);

void hmp_info_migrate_capabilities(Monitor *mon);

void hmp_info_migrate_cache_size(Monitor *mon);

void hmp_info_cpus(Monitor *mon);

void hmp_info_block(Monitor *mon);

void hmp_info_blockstats(Monitor *mon);
@@ -53,6 +54,7 @@ void hmp_migrate_cancel(Monitor *mon, const QDict *qdict); 
void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);

void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);

void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict);

void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);

void hmp_set_password(Monitor *mon, const QDict *qdict);

void hmp_expire_password(Monitor *mon, const QDict *qdict);

void hmp_eject(Monitor *mon, const QDict *qdict);

migration.c

+19 −0
Original line number Diff line number Diff line
@@ -511,6 +511,25 @@ void qmp_migrate_cancel(Error **errp) 
    migrate_fd_cancel(migrate_get_current());

}



void qmp_migrate_set_cache_size(int64_t value, Error **errp)

{

    MigrationState *s = migrate_get_current();



    /* Check for truncation */

    if (value != (size_t)value) {

        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",

                  "exceeding address space");

        return;

    }



    s->xbzrle_cache_size = xbzrle_cache_resize(value);

}



int64_t qmp_query_migrate_cache_size(Error **errp)

{

    return migrate_xbzrle_cache_size();

}



void qmp_migrate_set_speed(int64_t value, Error **errp)

{

    MigrationState *s;