@@ -50,6 +50,15 @@ enum mig_rp_message_type {
};
typedef QLIST_HEAD(, LoadStateEntry) LoadStateEntry_Head;
+
+typedef enum {
+ POSTCOPY_INCOMING_NONE = 0, /* Initial state - no postcopy */
+ POSTCOPY_INCOMING_ADVISE,
+ POSTCOPY_INCOMING_LISTENING,
+ POSTCOPY_INCOMING_RUNNING,
+ POSTCOPY_INCOMING_END
+} PostcopyState;
+
/* State for the incoming migration */
struct MigrationIncomingState {
QEMUFile *file;
@@ -62,6 +71,7 @@ struct MigrationIncomingState {
QEMUFile *return_path;
QemuMutex rp_mutex; /* We send replies from multiple threads */
+ PostcopyState postcopy_state;
/* See savevm.c */
LoadStateEntry_Head loadvm_handlers;
@@ -231,4 +241,10 @@ size_t ram_control_save_page(QEMUFile *f, ram_addr_t block_offset,
void ram_mig_init(void);
void savevm_skip_section_footers(void);
+
+PostcopyState postcopy_state_get(MigrationIncomingState *mis);
+
+/* Set the state and return the old state */
+PostcopyState postcopy_state_set(MigrationIncomingState *mis,
+ PostcopyState new_state);
#endif
@@ -87,6 +87,17 @@ enum qemu_vm_cmd {
MIG_CMD_INVALID = 0, /* Must be 0 */
MIG_CMD_OPEN_RETURN_PATH, /* Tell the dest to open the Return path */
MIG_CMD_PING, /* Request a PONG on the RP */
+
+ MIG_CMD_POSTCOPY_ADVISE = 20, /* Prior to any page transfers, just
+ warn we might want to do PC */
+ MIG_CMD_POSTCOPY_LISTEN, /* Start listening for incoming
+ pages as it's running. */
+ MIG_CMD_POSTCOPY_RUN, /* Start execution */
+
+ MIG_CMD_POSTCOPY_RAM_DISCARD, /* A list of pages to discard that
+ were previously sent during
+ precopy but are dirty. */
+
};
bool qemu_savevm_state_blocked(Error **errp);
@@ -101,6 +112,15 @@ void qemu_savevm_command_send(QEMUFile *f, enum qemu_vm_cmd command,
uint16_t len, uint8_t *data);
void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
void qemu_savevm_send_open_return_path(QEMUFile *f);
+void qemu_savevm_send_postcopy_advise(QEMUFile *f);
+void qemu_savevm_send_postcopy_listen(QEMUFile *f);
+void qemu_savevm_send_postcopy_run(QEMUFile *f);
+
+void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
+ uint16_t len,
+ uint64_t *start_list,
+ uint64_t *end_list);
+
int qemu_loadvm_state(QEMUFile *f);
typedef enum DisplayType
@@ -1128,3 +1128,16 @@ void migrate_fd_connect(MigrationState *s)
qemu_thread_create(&s->thread, "migration", migration_thread, s,
QEMU_THREAD_JOINABLE);
}
+
+PostcopyState postcopy_state_get(MigrationIncomingState *mis)
+{
+ return atomic_fetch_add(&mis->postcopy_state, 0);
+}
+
+/* Set the state and return the old state */
+PostcopyState postcopy_state_set(MigrationIncomingState *mis,
+ PostcopyState new_state)
+{
+ return atomic_xchg(&mis->postcopy_state, new_state);
+}
+
@@ -43,6 +43,7 @@
#include "exec/memory.h"
#include "qmp-commands.h"
#include "trace.h"
+#include "qemu/bitops.h"
#include "qemu/iov.h"
#include "block/snapshot.h"
#include "block/qapi.h"
@@ -717,6 +718,77 @@ void qemu_savevm_send_open_return_path(QEMUFile *f)
qemu_savevm_command_send(f, MIG_CMD_OPEN_RETURN_PATH, 0, NULL);
}
+/* Send prior to any postcopy transfer */
+void qemu_savevm_send_postcopy_advise(QEMUFile *f)
+{
+ uint64_t tmp[2];
+ tmp[0] = cpu_to_be64(getpagesize());
+ tmp[1] = cpu_to_be64(1ul << qemu_target_page_bits());
+
+ trace_qemu_savevm_send_postcopy_advise();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_ADVISE, 16, (uint8_t *)tmp);
+}
+
+/* Sent prior to starting the destination running in postcopy, discard pages
+ * that have already been sent but redirtied on the source.
+ * CMD_POSTCOPY_RAM_DISCARD consist of:
+ * byte version (0)
+ * byte Length of name field (not including 0)
+ * n x byte RAM block name
+ * byte 0 terminator (just for safety)
+ * n x Byte ranges within the named RAMBlock
+ * be64 Start of the range
+ * be64 end of the range + 1
+ *
+ * name: RAMBlock name that these entries are part of
+ * len: Number of page entries
+ * start_list: 'len' addresses
+ * end_list: 'len' addresses
+ *
+ */
+void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
+ uint16_t len,
+ uint64_t *start_list,
+ uint64_t *end_list)
+{
+ uint8_t *buf;
+ uint16_t tmplen;
+ uint16_t t;
+ size_t name_len = strlen(name);
+
+ trace_qemu_savevm_send_postcopy_ram_discard(name, len);
+ buf = g_malloc0(len*16 + name_len + 3);
+ buf[0] = 0; /* Version */
+ assert(name_len < 256);
+ buf[1] = name_len;
+ memcpy(buf+2, name, name_len);
+ tmplen = 2+name_len;
+ buf[tmplen++] = '\0';
+
+ for (t = 0; t < len; t++) {
+ cpu_to_be64w((uint64_t *)(buf + tmplen), start_list[t]);
+ tmplen += 8;
+ cpu_to_be64w((uint64_t *)(buf + tmplen), end_list[t]);
+ tmplen += 8;
+ }
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RAM_DISCARD, tmplen, buf);
+ g_free(buf);
+}
+
+/* Get the destination into a state where it can receive postcopy data. */
+void qemu_savevm_send_postcopy_listen(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_listen();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_LISTEN, 0, NULL);
+}
+
+/* Kick the destination into running */
+void qemu_savevm_send_postcopy_run(QEMUFile *f)
+{
+ trace_savevm_send_postcopy_run();
+ qemu_savevm_command_send(f, MIG_CMD_POSTCOPY_RUN, 0, NULL);
+}
+
bool qemu_savevm_state_blocked(Error **errp)
{
SaveStateEntry *se;
@@ -1020,6 +1092,154 @@ enum LoadVMExitCodes {
static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
+/* ------ incoming postcopy messages ------ */
+/* 'advise' arrives before any transfers just to tell us that a postcopy
+ * *might* happen - it might be skipped if precopy transferred everything
+ * quickly.
+ */
+static int loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
+ uint64_t remote_hps,
+ uint64_t remote_tps)
+{
+ PostcopyState ps = postcopy_state_get(mis);
+ trace_loadvm_postcopy_handle_advise();
+ if (ps != POSTCOPY_INCOMING_NONE) {
+ error_report("CMD_POSTCOPY_ADVISE in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ if (remote_hps != getpagesize()) {
+ /*
+ * Some combinations of mismatch are probably possible but it gets
+ * a bit more complicated. In particular we need to place whole
+ * host pages on the dest at once, and we need to ensure that we
+ * handle dirtying to make sure we never end up sending part of
+ * a hostpage on it's own.
+ */
+ error_report("Postcopy needs matching host page sizes (s=%d d=%d)",
+ (int)remote_hps, getpagesize());
+ return -1;
+ }
+
+ if (remote_tps != (1ul << qemu_target_page_bits())) {
+ /*
+ * Again, some differences could be dealt with, but for now keep it
+ * simple.
+ */
+ error_report("Postcopy needs matching target page sizes (s=%d d=%d)",
+ (int)remote_tps, 1 << qemu_target_page_bits());
+ return -1;
+ }
+
+ postcopy_state_set(mis, POSTCOPY_INCOMING_ADVISE);
+
+ return 0;
+}
+
+/* After postcopy we will be told to throw some pages away since they're
+ * dirty and will have to be demand fetched. Must happen before CPU is
+ * started.
+ * There can be 0..many of these messages, each encoding multiple pages.
+ */
+static int loadvm_postcopy_ram_handle_discard(MigrationIncomingState *mis,
+ uint16_t len)
+{
+ int tmp;
+ char ramid[256];
+ PostcopyState ps = postcopy_state_get(mis);
+
+ trace_loadvm_postcopy_ram_handle_discard();
+
+ if (ps != POSTCOPY_INCOMING_ADVISE) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD in wrong postcopy state (%d)",
+ ps);
+ return -1;
+ }
+ /* We're expecting a
+ * Version (0)
+ * a RAM ID string (length byte, name, 0 term)
+ * then at least 1 16 byte chunk
+ */
+ if (len < 20) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+ return -1;
+ }
+
+ tmp = qemu_get_byte(mis->file);
+ if (tmp != 0) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid version (%d)", tmp);
+ return -1;
+ }
+
+ if (!qemu_get_counted_string(mis->file, ramid)) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD Failed to read RAMBlock ID");
+ return -1;
+ }
+ tmp = qemu_get_byte(mis->file);
+ if (tmp != 0) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD missing nil (%d)", tmp);
+ return -1;
+ }
+
+ len -= 3+strlen(ramid);
+ if (len % 16) {
+ error_report("CMD_POSTCOPY_RAM_DISCARD invalid length (%d)", len);
+ return -1;
+ }
+ trace_loadvm_postcopy_ram_handle_discard_header(ramid, len);
+ while (len) {
+ /* TODO - ram_discard_range gets added in a later patch
+ uint64_t start_addr, end_addr;
+ start_addr = qemu_get_be64(mis->file);
+ end_addr = qemu_get_be64(mis->file);
+
+ len -= 16;
+ int ret = ram_discard_range(mis, ramid, start_addr, end_addr - 1);
+ if (ret) {
+ return ret;
+ }
+ */
+ }
+ trace_loadvm_postcopy_ram_handle_discard_end();
+
+ return 0;
+}
+
+/* After this message we must be able to immediately receive postcopy data */
+static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_set(mis, POSTCOPY_INCOMING_LISTENING);
+ trace_loadvm_postcopy_handle_listen();
+ if (ps != POSTCOPY_INCOMING_ADVISE) {
+ error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ /* TODO start up the postcopy listening thread */
+ return 0;
+}
+
+/* After all discards we can start running and asking for pages */
+static int loadvm_postcopy_handle_run(MigrationIncomingState *mis)
+{
+ PostcopyState ps = postcopy_state_set(mis, POSTCOPY_INCOMING_RUNNING);
+ trace_loadvm_postcopy_handle_run();
+ if (ps != POSTCOPY_INCOMING_LISTENING) {
+ error_report("CMD_POSTCOPY_RUN in wrong postcopy state (%d)", ps);
+ return -1;
+ }
+
+ if (autostart) {
+ /* Hold onto your hats, starting the CPU */
+ vm_start();
+ } else {
+ /* leave it paused and let management decide when to start the CPU */
+ runstate_set(RUN_STATE_PAUSED);
+ }
+
+ return 0;
+}
+
static int loadvm_process_command_simple_lencheck(const char *name,
unsigned int actual,
unsigned int expected)
@@ -1045,6 +1265,7 @@ static int loadvm_process_command(QEMUFile *f)
uint16_t cmd;
uint16_t len;
uint32_t tmp32;
+ uint64_t tmp64a, tmp64b;
cmd = qemu_get_be16(f);
len = qemu_get_be16(f);
@@ -1083,6 +1304,32 @@ static int loadvm_process_command(QEMUFile *f)
migrate_send_rp_pong(mis, tmp32);
break;
+ case MIG_CMD_POSTCOPY_ADVISE:
+ if (loadvm_process_command_simple_lencheck("CMD_POSTCOPY_ADVISE",
+ len, 16)) {
+ return -1;
+ }
+ tmp64a = qemu_get_be64(f); /* hps */
+ tmp64b = qemu_get_be64(f); /* tps */
+ return loadvm_postcopy_handle_advise(mis, tmp64a, tmp64b);
+
+ case MIG_CMD_POSTCOPY_LISTEN:
+ if (loadvm_process_command_simple_lencheck("CMD_POSTCOPY_LISTEN",
+ len, 0)) {
+ return -1;
+ }
+ return loadvm_postcopy_handle_listen(mis);
+
+ case MIG_CMD_POSTCOPY_RUN:
+ if (loadvm_process_command_simple_lencheck("CMD_POSTCOPY_RUN",
+ len, 0)) {
+ return -1;
+ }
+ return loadvm_postcopy_handle_run(mis);
+
+ case MIG_CMD_POSTCOPY_RAM_DISCARD:
+ return loadvm_postcopy_ram_handle_discard(mis, len);
+
default:
error_report("VM_COMMAND 0x%x unknown (len 0x%x)", cmd, len);
return -1;
@@ -1187,11 +1187,21 @@ qemu_loadvm_state_main(void) ""
qemu_loadvm_state_main_quit_parent(void) ""
qemu_loadvm_state_post_main(int ret) "%d"
qemu_loadvm_state_section_startfull(uint32_t section_id, const char *idstr, uint32_t instance_id, uint32_t version_id) "%u(%s) %u %u"
+loadvm_postcopy_handle_advise(void) ""
+loadvm_postcopy_handle_listen(void) ""
+loadvm_postcopy_handle_run(void) ""
+loadvm_postcopy_ram_handle_discard(void) ""
+loadvm_postcopy_ram_handle_discard_end(void) ""
+loadvm_postcopy_ram_handle_discard_header(const char *ramid, uint16_t len) "%s: %ud"
loadvm_process_command(uint16_t com, uint16_t len) "com=0x%x len=%d"
loadvm_process_command_ping(uint32_t val) "%x"
+qemu_savevm_send_postcopy_advise(void) ""
+qemu_savevm_send_postcopy_ram_discard(const char *id, uint16_t len) "%s: %ud"
savevm_section_start(const char *id, unsigned int section_id) "%s, section_id %u"
savevm_section_end(const char *id, unsigned int section_id, int ret) "%s, section_id %u -> %d"
savevm_send_ping(uint32_t val) "%x"
+savevm_send_postcopy_listen(void) ""
+savevm_send_postcopy_run(void) ""
savevm_state_begin(void) ""
savevm_state_header(void) ""
savevm_state_iterate(void) ""