From 6c595cdee116dc46b0d4d7d632a426681ae66ad9 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Thu, 5 Nov 2015 18:11:08 +0000 Subject: [PATCH] Page request: Process incoming page request On receiving MIG_RPCOMM_REQ_PAGES look up the address and queue the page. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Amit Shah Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- include/migration/migration.h | 22 +++++++++++ migration/migration.c | 31 +++++++++++++++- migration/ram.c | 85 +++++++++++++++++++++++++++++++++++++++++++ trace-events | 1 + 4 files changed, 138 insertions(+), 1 deletion(-) diff --git a/include/migration/migration.h b/include/migration/migration.h index 1046d4e370..1491bf32ed 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -105,6 +105,18 @@ MigrationIncomingState *migration_incoming_get_current(void); MigrationIncomingState *migration_incoming_state_new(QEMUFile *f); void migration_incoming_state_destroy(void); +/* + * An outstanding page request, on the source, having been received + * and queued + */ +struct MigrationSrcPageRequest { + RAMBlock *rb; + hwaddr offset; + hwaddr len; + + QSIMPLEQ_ENTRY(MigrationSrcPageRequest) next_req; +}; + struct MigrationState { int64_t bandwidth_limit; @@ -141,6 +153,12 @@ struct MigrationState /* Flag set once the migration thread is running (and needs joining) */ bool migration_thread_running; + + /* Queue of outstanding page requests from the destination */ + QemuMutex src_page_req_mutex; + QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests; + /* The RAMBlock used in the last src_page_request */ + RAMBlock *last_req_rb; }; void process_incoming_migration(QEMUFile *f); @@ -288,6 +306,10 @@ void savevm_skip_configuration(void); int global_state_store(void); void global_state_store_running(void); +void flush_page_queue(MigrationState *ms); +int ram_save_queue_pages(MigrationState *ms, const char *rbname, + ram_addr_t start, ram_addr_t len); + PostcopyState postcopy_state_get(void); /* Set the state and return the old state */ PostcopyState postcopy_state_set(PostcopyState new_state); diff --git a/migration/migration.c b/migration/migration.c index 6ccdeb8023..7d64cd3240 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -21,6 +21,7 @@ #include "sysemu/sysemu.h" #include "block/block.h" #include "qapi/qmp/qerror.h" +#include "qapi/util.h" #include "qemu/sockets.h" #include "qemu/rcu.h" #include "migration/block.h" @@ -28,9 +29,10 @@ #include "qemu/thread.h" #include "qmp-commands.h" #include "trace.h" -#include "qapi/util.h" #include "qapi-event.h" #include "qom/cpu.h" +#include "exec/memory.h" +#include "exec/address-spaces.h" #define MAX_THROTTLE (32 << 20) /* Migration transfer speed throttling */ @@ -72,6 +74,7 @@ static PostcopyState incoming_postcopy_state; /* For outgoing */ MigrationState *migrate_get_current(void) { + static bool once; static MigrationState current_migration = { .state = MIGRATION_STATUS_NONE, .bandwidth_limit = MAX_THROTTLE, @@ -89,6 +92,10 @@ MigrationState *migrate_get_current(void) DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT, }; + if (!once) { + qemu_mutex_init(¤t_migration.src_page_req_mutex); + once = true; + } return ¤t_migration; } @@ -771,6 +778,8 @@ static void migrate_fd_cleanup(void *opaque) qemu_bh_delete(s->cleanup_bh); s->cleanup_bh = NULL; + flush_page_queue(s); + if (s->file) { trace_migrate_fd_cleanup(); qemu_mutex_unlock_iothread(); @@ -903,6 +912,8 @@ MigrationState *migrate_init(const MigrationParams *params) s->bandwidth_limit = bandwidth_limit; migrate_set_state(s, MIGRATION_STATUS_NONE, MIGRATION_STATUS_SETUP); + QSIMPLEQ_INIT(&s->src_page_requests); + s->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); return s; } @@ -1193,7 +1204,25 @@ static struct rp_cmd_args { static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, ram_addr_t start, size_t len) { + long our_host_ps = getpagesize(); + trace_migrate_handle_rp_req_pages(rbname, start, len); + + /* + * Since we currently insist on matching page sizes, just sanity check + * we're being asked for whole host pages. + */ + if (start & (our_host_ps-1) || + (len & (our_host_ps-1))) { + error_report("%s: Misaligned page request, start: " RAM_ADDR_FMT + " len: %zd", __func__, start, len); + mark_source_rp_bad(ms); + return; + } + + if (ram_save_queue_pages(ms, rbname, start, len)) { + mark_source_rp_bad(ms); + } } /* diff --git a/migration/ram.c b/migration/ram.c index 2e27b26d4c..8302d097c5 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1016,6 +1016,91 @@ static bool find_dirty_block(QEMUFile *f, PageSearchStatus *pss, } /** + * flush_page_queue: Flush any remaining pages in the ram request queue + * it should be empty at the end anyway, but in error cases there may be + * some left. + * + * ms: MigrationState + */ +void flush_page_queue(MigrationState *ms) +{ + struct MigrationSrcPageRequest *mspr, *next_mspr; + /* This queue generally should be empty - but in the case of a failed + * migration might have some droppings in. + */ + rcu_read_lock(); + QSIMPLEQ_FOREACH_SAFE(mspr, &ms->src_page_requests, next_req, next_mspr) { + memory_region_unref(mspr->rb->mr); + QSIMPLEQ_REMOVE_HEAD(&ms->src_page_requests, next_req); + g_free(mspr); + } + rcu_read_unlock(); +} + +/** + * Queue the pages for transmission, e.g. a request from postcopy destination + * ms: MigrationStatus in which the queue is held + * rbname: The RAMBlock the request is for - may be NULL (to mean reuse last) + * start: Offset from the start of the RAMBlock + * len: Length (in bytes) to send + * Return: 0 on success + */ +int ram_save_queue_pages(MigrationState *ms, const char *rbname, + ram_addr_t start, ram_addr_t len) +{ + RAMBlock *ramblock; + + rcu_read_lock(); + if (!rbname) { + /* Reuse last RAMBlock */ + ramblock = ms->last_req_rb; + + if (!ramblock) { + /* + * Shouldn't happen, we can't reuse the last RAMBlock if + * it's the 1st request. + */ + error_report("ram_save_queue_pages no previous block"); + goto err; + } + } else { + ramblock = qemu_ram_block_by_name(rbname); + + if (!ramblock) { + /* We shouldn't be asked for a non-existent RAMBlock */ + error_report("ram_save_queue_pages no block '%s'", rbname); + goto err; + } + ms->last_req_rb = ramblock; + } + trace_ram_save_queue_pages(ramblock->idstr, start, len); + if (start+len > ramblock->used_length) { + error_report("%s request overrun start=%zx len=%zx blocklen=%zx", + __func__, start, len, ramblock->used_length); + goto err; + } + + struct MigrationSrcPageRequest *new_entry = + g_malloc0(sizeof(struct MigrationSrcPageRequest)); + new_entry->rb = ramblock; + new_entry->offset = start; + new_entry->len = len; + + memory_region_ref(ramblock->mr); + qemu_mutex_lock(&ms->src_page_req_mutex); + QSIMPLEQ_INSERT_TAIL(&ms->src_page_requests, new_entry, next_req); + qemu_mutex_unlock(&ms->src_page_req_mutex); + rcu_read_unlock(); + + return 0; + +err: + rcu_read_unlock(); + return -1; +} + + +/** * ram_find_and_save_block: Finds a dirty page and sends it to f * * Called within an RCU critical section. diff --git a/trace-events b/trace-events index 2bafa12f52..0914e0a2a2 100644 --- a/trace-events +++ b/trace-events @@ -1256,6 +1256,7 @@ migration_bitmap_sync_start(void) "" migration_bitmap_sync_end(uint64_t dirty_pages) "dirty_pages %" PRIu64"" migration_throttle(void) "" ram_postcopy_send_discard_bitmap(void) "" +ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: %zx len: %zx" # hw/display/qxl.c disable qxl_interface_set_mm_time(int qid, uint32_t mm_time) "%d %d" -- 2.11.4.GIT