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author | Ian Campbell <ian.campbell@citrix.com> | 2010-09-07 19:08:11 +0100 |
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committer | Ian Campbell <ian.campbell@citrix.com> | 2010-09-07 19:08:11 +0100 |
commit | 00a4b65f8534c9e6521eab2e6ce796ae36037774 (patch) | |
tree | 6c3494e0dcb6f1e7214becfd7fe88772d0d45e17 /tools | |
parent | ec7b9a1b9b2a935fa322eca98d95741ff6d162bb (diff) | |
download | xen-00a4b65f8534c9e6521eab2e6ce796ae36037774.tar.gz xen-00a4b65f8534c9e6521eab2e6ce796ae36037774.tar.bz2 xen-00a4b65f8534c9e6521eab2e6ce796ae36037774.zip |
libxc: provide notification of final checkpoint to restore end
When the restore code sees this notification it will restore the
currently in-progress checkpoint when it completes.
This allows the restore end to finish up without waiting for a
spurious timeout on the receive fd and thereby avoids unnecessary
error logging in the case of a successful migration or restore.
In the normal migration or restore case the first checkpoint is always
the last. For a rolling checkpoint (such as Remus) the notification is
currently unused but could be used in the future for example to
provide a controlled failover for reasons other than error
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Brendan Cully <brendan@cs.ubc.ca>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/libxc/xc_domain_restore.c | 27 | ||||
-rw-r--r-- | tools/libxc/xc_domain_save.c | 14 | ||||
-rw-r--r-- | tools/libxc/xg_save_restore.h | 1 |
3 files changed, 38 insertions, 4 deletions
diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c index 4c7aa0c1e5..6ba5c7580d 100644 --- a/tools/libxc/xc_domain_restore.c +++ b/tools/libxc/xc_domain_restore.c @@ -42,6 +42,7 @@ struct restore_ctx { xen_pfn_t *p2m; /* A table mapping each PFN to its new MFN. */ xen_pfn_t *p2m_batch; /* A table of P2M mappings in the current region. */ int completed; /* Set when a consistent image is available */ + int last_checkpoint; /* Set when we should commit to the current checkpoint when it completes. */ struct domain_info_context dinfo; }; @@ -765,6 +766,11 @@ static int pagebuf_get_one(xc_interface *xch, struct restore_ctx *ctx, // DPRINTF("console pfn location: %llx\n", buf->console_pfn); return pagebuf_get_one(xch, ctx, buf, fd, dom); + case XC_SAVE_ID_LAST_CHECKPOINT: + ctx->last_checkpoint = 1; + // DPRINTF("last checkpoint indication received"); + return pagebuf_get_one(xch, ctx, buf, fd, dom); + default: if ( (count > MAX_BATCH_SIZE) || (count < 0) ) { ERROR("Max batch size exceeded (%d). Giving up.", count); @@ -1296,10 +1302,23 @@ int xc_domain_restore(xc_interface *xch, int io_fd, uint32_t dom, goto out; } ctx->completed = 1; - /* shift into nonblocking mode for the remainder */ - if ( (flags = fcntl(io_fd, F_GETFL,0)) < 0 ) - flags = 0; - fcntl(io_fd, F_SETFL, flags | O_NONBLOCK); + + /* + * If more checkpoints are expected then shift into + * nonblocking mode for the remainder. + */ + if ( !ctx->last_checkpoint ) + { + if ( (flags = fcntl(io_fd, F_GETFL,0)) < 0 ) + flags = 0; + fcntl(io_fd, F_SETFL, flags | O_NONBLOCK); + } + } + + if ( ctx->last_checkpoint ) + { + // DPRINTF("Last checkpoint, finishing\n"); + goto finish; } // DPRINTF("Buffered checkpoint\n"); diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c index ef33fa1134..15c4da3cba 100644 --- a/tools/libxc/xc_domain_save.c +++ b/tools/libxc/xc_domain_save.c @@ -1616,6 +1616,20 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter } } + if ( !callbacks->checkpoint ) + { + /* + * If this is not a checkpointed save then this must be the first and + * last checkpoint. + */ + i = XC_SAVE_ID_LAST_CHECKPOINT; + if ( wrexact(io_fd, &i, sizeof(int)) ) + { + PERROR("Error when writing last checkpoint chunk"); + goto out; + } + } + /* Zero terminate */ i = 0; if ( wrexact(io_fd, &i, sizeof(int)) ) diff --git a/tools/libxc/xg_save_restore.h b/tools/libxc/xg_save_restore.h index a16e6f3b7c..0bc958344c 100644 --- a/tools/libxc/xg_save_restore.h +++ b/tools/libxc/xg_save_restore.h @@ -131,6 +131,7 @@ #define XC_SAVE_ID_TMEM_EXTRA -6 #define XC_SAVE_ID_TSC_INFO -7 #define XC_SAVE_ID_HVM_CONSOLE_PFN -8 /* (HVM-only) */ +#define XC_SAVE_ID_LAST_CHECKPOINT -9 /* Commit to restoring after completion of current iteration. */ /* ** We process save/restore/migrate in batches of pages; the below |