I hit this problem recently when trying to create a bridge with an IPv6
address on a 3.2 kernel: dnsmasq (and, further, radvd) would not bind to
the given address, waiting 20s and then giving up with -EADDRNOTAVAIL
(resp. exiting immediately with "error parsing or activating the config
file", without libvirt noticing it, BTW). This can be reproduced with (I
think) any kernel >= 2.6.39 and the following XML (to be used with
"virsh net-create"):
<network>
<name>test-bridge</name>
<bridge name='testbr0' />
<ip family='ipv6' address='fd00::1' prefix='64'>
</ip>
</network>
(it happens even when you have an IPv4, too)
The problem is that since commit [1] (which, ironically, was made to
“help IPv6 autoconfiguration”) the linux bridge code makes bridges
behave like “real” devices regarding carrier detection. This makes the
bridges created by libvirt, which are started without any up devices,
stay with the NO-CARRIER flag set, and thus prevents DAD (Duplicate
address detection) from happening, thus letting the IPv6 address flagged
as “tentative”. Such addresses cannot be bound to (see RFC 2462), so
dnsmasq fails binding to it (for radvd, it detects that "interface XXX
is not RUNNING", thus that "interface XXX does not exist, ignoring the
interface" (sic)). It seems that this behavior was enhanced somehow with
commit [2] by avoiding setting NO-CARRIER on empty bridges, but I
couldn't reproduce this behavior on my kernel. Anyway, with the “dummy
tap to set MAC address” trick, this wouldn't work.
To fix this, the idea is to get the bridge's attached device to be up so
that DAD can happen (deactivating DAD altogether is not a good idea, I
think). Currently, libvirt creates a dummy TAP device to set the MAC
address of the bridge, keeping it down. But even if we set this device
up, it is not RUNNING as soon as the tap file descriptor attached to it
is closed, thus still preventing DAD. So, we must modify the API a bit,
so that we can get the fd, keep the tap device persistent, run the
daemons, and close it after DAD has taken place. After that, the bridge
will be flagged NO-CARRIER again, but the daemons will be running, even
if not happy about the device's state (but we don't really care about
the bridge's daemons doing anything when no up interface is connected to
it).
Other solutions that I envisioned were:
* Keeping the *-nic interface up: this would waste an fd for each
bridge during all its life. May be acceptable, I don't really
know.
* Stop using the dummy tap trick, and set the MAC address directly
on the bridge: it is possible since quite some time it seems,
even if then there is the problem of the bridge not being
RUNNING when empty, contrary to what [2] says, so this will need
fixing (and this fix only happened in 3.1, so it wouldn't work
for 2.6.39)
* Using the --interface option of dnsmasq, but I saw somewhere
that it's not used by libvirt for backward compatibility. I am
not sure this would solve this problem, though, as I don't know
how dnsmasq binds itself to it with this option.
This is why this patch does what's described earlier.
This patch also makes radvd start even if the interface is
“missing” (i.e. it is not RUNNING), as it daemonizes before binding to
it, and thus sometimes does it after the interface has been brought down
by us (by closing the tap fd), and then originally stops. This also
makes it stop yelling about it in the logs when the interface is down at
a later time.
[1]
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=1faa4356a3bd89ea11fb92752d897cff3a20ec0e
[2]
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=b64b73d7d0c480f75684519c6134e79d50c1b341
QEMU (and librbd) flush the cache on the source before the
destination starts, and the destination does not read any
changeable data before that, so live migration with rbd caching
is safe.
This makes 'virsh migrate' work with rbd and caching without the
--unsafe flag.
Reported-by: Vladimir Bashkirtsev <vladimir@bashkirtsev.com>
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Code altered so that it is consistent with the associated comment. The
'autoconf' variable is forced to zero.
Signed-off-by: Neil Wilson <neil@brightbox.co.uk>
Alex recently committed some patches with just an email instead
of a preferred name; this fixes things so 'git shortlog' gives
nicer output.
* .mailmap: Update.
From a security pov copy and paste between the guest and the client is not
always desirable. So we need to be able to enable/disable this. The best place
to do this from an administration pov is on the hypervisor, so the qemu cmdline
is getting a spice disable-copy-paste option, see bug 693645. Example qemu
invocation:
qemu -spice port=5932,disable-ticketing,disable-copy-paste
https://bugzilla.redhat.com/show_bug.cgi?id=693661
Originally most of libvirt domain-specific calls were blocking
during a migration.
A new mechanism to allow specific calls (blkstat/blkinfo) to be
executed in such condition has been implemented.
In the long term it'd be desirable to get a more general
solution to mark further APIs as migration safe, without needing
special case code.
* src/qemu/qemu_migration.c: add some additional job signal
flags for doing blkstat/blkinfo during a migration
* src/qemu/qemu_domain.c: add a condition variable that can be
used to efficiently wait for the migration code to clear the
signal flag
* src/qemu/qemu_driver.c: execute blkstat/blkinfo using the
job signal flags during migration
When using TLS authentication and operating as the non-root user,
initially attempt to use that specific user's TLS certificates before
attempting to use the system wide TLS certificates.
Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
gcc 4.6 warns when a variable is initialized but isn't used afterwards:
vmware/vmware_driver.c:449:18: warning: variable 'vmxPath' set but not used [-Wunused-but-set-variable]
This patch fixes these warnings. There are still 2 offending files:
- vbox_tmpl.c: the variable is used inside an #ifdef and is assigned several
times outside of #ifdef. Fixing the warning would have required wrapping
all the assignment inside #ifdef which hurts readability.
vbox/vbox_tmpl.c: In function 'vboxAttachDrives':
vbox/vbox_tmpl.c:3918:22: warning: variable 'accessMode' set but not used [-Wunused-but-set-variable]
- esx_vi_types.generated.c: the name implies it's generated code and I
didn't want to dive into the code generator
esx/esx_vi_types.generated.c: In function 'esxVI_FileQueryFlags_Free':
esx/esx_vi_types.generated.c:1203:3: warning: variable 'item' set but not used [-Wunused-but-set-variable]
virDiskNameToIndex has a list of disk name prefixes that it uses in the
process of finding the disk's index. This list is missing "ubd" which
is the disk prefix used for UML domains.
Signed-off-by: Soren Hansen <soren@linux2go.dk>
