* Alexander Graf (ag...@suse.de) wrote: <snip>
> Can you please test whether the patch below makes things work for you again? The patch below fixes RDMA migration (same host); however, see comments. > Alex > > From ef6fde21007e62529799264f57a65c6bb3d0d414 Mon Sep 17 00:00:00 2001 > From: Alexander Graf <ag...@suse.de> > Date: Sat, 14 Feb 2015 00:21:01 +0100 > Subject: [PATCH] migration: Read JSON VM description on incoming migration > > One of the really nice things about the VM description format is that it > goes > over the wire when live migration is happening. Unfortunately QEMU today > closes > any socket once it sees VM_EOF coming, so we never give the VMDESC the > chance to > actually land on the wire. > > This patch makes QEMU read the description as well. This way we ensure that > anything wire tapping us in between will get the chance to also > interpret the > stream. > > Along the way we also fix virt tests that assume that number_bytes_sent > on the > sender side is equal to number_bytes_read which was true before the VMDESC > patches and is true again with this patch. > > Signed-off-by: Alexander Graf <ag...@suse.de> > > diff --git a/savevm.c b/savevm.c > index 8040766..ff4bead 100644 > --- a/savevm.c > +++ b/savevm.c > @@ -929,6 +929,7 @@ int qemu_loadvm_state(QEMUFile *f) > uint8_t section_type; > unsigned int v; > int ret; > + int file_error_after_eof = -1; > > if (qemu_savevm_state_blocked(&local_err)) { > error_report("%s", error_get_pretty(local_err)); > @@ -1034,6 +1035,22 @@ int qemu_loadvm_state(QEMUFile *f) > } > } > > + file_error_after_eof = qemu_file_get_error(f); > + > + /* > + * Try to read in the VMDESC section as well, so that dumping tools > that > + * intercept our migration stream have the chance to see it. > + */ > + if (qemu_get_byte(f) == QEMU_VM_VMDESCRIPTION) { You could use qemu_peek_byte for that? > + uint32_t size = qemu_get_be32(f); > + uint8_t *buf = g_malloc(size); > + > + if (buf) { > + qemu_get_buffer(f, buf, size); > + g_free(buf); > + } This is slightly dangerous; a malformed file could send you a huge value and get you to allocate lots of memory for no good reason. You could do some clever; but personally I'd just loop around a nice small buffer until it's gone. As mentioned on IRC; I'm still worried though that this is only a fix for loading on newer versions; migration to an older QEMU with the same machine type would fail. (Yes I know mythically that no one cares about this; but I do). Dave > + } > + > cpu_synchronize_all_post_init(); > > ret = 0; > @@ -1045,7 +1062,8 @@ out: > } > > if (ret == 0) { > - ret = qemu_file_get_error(f); > + /* We may not have a VMDESC section, so ignore relative errors */ > + ret = file_error_after_eof; > } > > return ret; -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK