From 1e2d90ebc54531c416a6765849308c8476d98f2d Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Thu, 5 Nov 2015 18:11:07 +0000 Subject: Page request: Add MIG_RP_MSG_REQ_PAGES reverse command Add MIG_RP_MSG_REQ_PAGES command on Return path for the postcopy destination to request a page from the source. Two versions exist: MIG_RP_MSG_REQ_PAGES_ID that includes a RAMBlock name and start/len MIG_RP_MSG_REQ_PAGES that just has start/len for use with the same RAMBlock as a previous MIG_RP_MSG_REQ_PAGES_ID Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Juan Quintela Reviewed-by: Amit Shah Signed-off-by: Juan Quintela --- migration/migration.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) (limited to 'migration') diff --git a/migration/migration.c b/migration/migration.c index 3cdb4f7257..6ccdeb8023 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -259,6 +259,35 @@ static void deferred_incoming_migration(Error **errp) deferred_incoming = true; } +/* Request a range of pages from the source VM at the given + * start address. + * rbname: Name of the RAMBlock to request the page in, if NULL it's the same + * as the last request (a name must have been given previously) + * Start: Address offset within the RB + * Len: Length in bytes required - must be a multiple of pagesize + */ +void migrate_send_rp_req_pages(MigrationIncomingState *mis, const char *rbname, + ram_addr_t start, size_t len) +{ + uint8_t bufc[12 + 1 + 255]; /* start (8), len (4), rbname upto 256 */ + size_t msglen = 12; /* start + len */ + + *(uint64_t *)bufc = cpu_to_be64((uint64_t)start); + *(uint32_t *)(bufc + 8) = cpu_to_be32((uint32_t)len); + + if (rbname) { + int rbname_len = strlen(rbname); + assert(rbname_len < 256); + + bufc[msglen++] = rbname_len; + memcpy(bufc + msglen, rbname, rbname_len); + msglen += rbname_len; + migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES_ID, msglen, bufc); + } else { + migrate_send_rp_message(mis, MIG_RP_MSG_REQ_PAGES, msglen, bufc); + } +} + void qemu_start_incoming_migration(const char *uri, Error **errp) { const char *p; @@ -1151,9 +1180,22 @@ static struct rp_cmd_args { [MIG_RP_MSG_INVALID] = { .len = -1, .name = "INVALID" }, [MIG_RP_MSG_SHUT] = { .len = 4, .name = "SHUT" }, [MIG_RP_MSG_PONG] = { .len = 4, .name = "PONG" }, + [MIG_RP_MSG_REQ_PAGES] = { .len = 12, .name = "REQ_PAGES" }, + [MIG_RP_MSG_REQ_PAGES_ID] = { .len = -1, .name = "REQ_PAGES_ID" }, [MIG_RP_MSG_MAX] = { .len = -1, .name = "MAX" }, }; +/* + * Process a request for pages received on the return path, + * We're allowed to send more than requested (e.g. to round to our page size) + * and we don't need to send pages that have already been sent. + */ +static void migrate_handle_rp_req_pages(MigrationState *ms, const char* rbname, + ram_addr_t start, size_t len) +{ + trace_migrate_handle_rp_req_pages(rbname, start, len); +} + /* * Handles messages sent on the return path towards the source VM * @@ -1166,6 +1208,8 @@ static void *source_return_path_thread(void *opaque) const int max_len = 512; uint8_t buf[max_len]; uint32_t tmp32, sibling_error; + ram_addr_t start = 0; /* =0 to silence warning */ + size_t len = 0, expected_len; int res; trace_source_return_path_thread_entry(); @@ -1225,6 +1269,32 @@ static void *source_return_path_thread(void *opaque) trace_source_return_path_thread_pong(tmp32); break; + case MIG_RP_MSG_REQ_PAGES: + start = be64_to_cpup((uint64_t *)buf); + len = be32_to_cpup((uint32_t *)(buf + 8)); + migrate_handle_rp_req_pages(ms, NULL, start, len); + break; + + case MIG_RP_MSG_REQ_PAGES_ID: + expected_len = 12 + 1; /* header + termination */ + + if (header_len >= expected_len) { + start = be64_to_cpup((uint64_t *)buf); + len = be32_to_cpup((uint32_t *)(buf + 8)); + /* Now we expect an idstr */ + tmp32 = buf[12]; /* Length of the following idstr */ + buf[13 + tmp32] = '\0'; + expected_len += tmp32; + } + if (header_len != expected_len) { + error_report("RP: Req_Page_id with length %d expecting %zd", + header_len, expected_len); + mark_source_rp_bad(ms); + goto out; + } + migrate_handle_rp_req_pages(ms, (char *)&buf[13], start, len); + break; + default: break; } -- cgit v1.2.1