From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45177) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YT7p1-0001rA-El for qemu-devel@nongnu.org; Wed, 04 Mar 2015 06:50:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YT7oy-00086n-IE for qemu-devel@nongnu.org; Wed, 04 Mar 2015 06:50:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46777) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YT7oy-00086e-71 for qemu-devel@nongnu.org; Wed, 04 Mar 2015 06:50:36 -0500 Date: Wed, 4 Mar 2015 11:50:30 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20150304115030.GA2530@work-vm> References: <1424696203-76895-1-git-send-email-agraf@suse.de> <1424696203-76895-2-git-send-email-agraf@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1424696203-76895-2-git-send-email-agraf@suse.de> Subject: Re: [Qemu-devel] [PATCH v2 1/3] migration: Read JSON VM description on incoming migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: lmr@redhat.com, amit.shah@redhat.com, qemu-devel@nongnu.org, quintela@redhat.com * Alexander Graf (agraf@suse.de) wrote: > 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 Reviewed-by: Dr. David Alan Gilbert and I've tested the set of 3 and it works, so: Tested-by: Dr. David Alan Gilbert Dave > > --- > > v1 -> v2: > > - read in small chunks > --- > savevm.c | 22 +++++++++++++++++++++- > 1 file changed, 21 insertions(+), 1 deletion(-) > > diff --git a/savevm.c b/savevm.c > index 8040766..1b78654 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 +1035,24 @@ 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) { > + uint32_t size = qemu_get_be32(f); > + uint8_t *buf = g_malloc(0x1000); > + > + while (size > 0) { > + uint32_t read_chunk = MIN(size, 0x1000); > + qemu_get_buffer(f, buf, read_chunk); > + size -= read_chunk; > + } > + g_free(buf); > + } > + > cpu_synchronize_all_post_init(); > > ret = 0; > @@ -1045,7 +1064,8 @@ 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; > -- > 1.7.12.4 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK