The current version of the qemu managed save implementation
is subject to a race where the domain shuts down between
the time that we start the command and the time that we
actually try to do the save. Close this race by making
qemuDomainSaveFlags() expect both the driver and the passed-in
vm object to be locked before executing.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
When reconnecting to existing VMs, we re-reserved only those PCI
addresses which were explicitly mentioned in domain XML. Since some
addresses are always reserved (e.g., 0:0:0 and 0:0:1), we need to handle
those too.
Also all this should only be done if device flag is supported by qemu.
In this patch I am extending and fixing the nwfilter module's reload support to stop all ongoing threads (for learning IP addresses of interfaces) and rebuild the filtering rules of all interfaces of all VMs when libvirt is started. Now libvirtd rebuilds the filters upon the SIGHUP signal and libvirtd restart.
About the patch: The nwfilter functions require a virConnectPtr. Therefore I am opening a connection in qemudStartup, which later on needs to be closed outside where the driver lock is held since otherwise it ends up in a deadlock due to virConnectClose() trying to lock the driver as well.
I have tested this now for a while with several machines running and needing the IP address learner thread(s). The rebuilding of the firewall rules seems to work fine following libvirtd restart or a SIGHUP. Also the termination of libvirtd worked fine.
Since the qemu process is running as qemu:qemu, it can't actually
look at the unix socket in /var/run/libvirt/qemu which is owned by
root and has permission 700. Move the unix socket to
/var/lib/libvirt/qemu, which is already owned by qemu:qemu.
Thanks to Justin Clift for test this out for me.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
The problem is that on the source of the migration, libvirtd
is responsible for creating the unix socket over which the data
will flow. Since libvirtd is running as root, this file will
be created as root. When the qemu process running as qemu:qemu
goes to access the unix file to write data to it, it will get
permission denied and fail. Make sure to change the owner
of the unix file to qemu:qemu.
Thanks to Justin Clift for testing this patch out for me.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Basically a followup of the previous patch about balloon desactivation
if desactivated, to not ask for balloon information to qemu as we will
just get an error back.
This can make a huge difference in the time needed for domain
information or list when a machine is loaded, and balloon has been
desactivated in the guests.
* src/qemu/qemu_driver.c: do not get the balloon info if the balloon
suppor is disabled
The balloon device is automatically added to qemu guests if supported,
but it may be useful to desactivate it. The simplest to not change the
existing behaviour is to allow
<memballoon type="none"/>
as an extra option to desactivate it (it is automatically added if the
memballoon construct is missing for the domain).
The following simple patch just adds the extra option and does not
change the default behaviour but avoid creating a balloon device if
type="none" is used.
* docs/schemas/domain.rng: add the extra type attribute value
* src/conf/domain_conf.c src/conf/domain_conf.h: add the extra enum
value
* src/qemu/qemu_conf.c: if enum is NONE, don't activate the device,
i.e. don't pass the args to qemu/kvm
device_del command is not synchronous for PCI devices, it merely asks
the guest to release the device and returns. If the host wants to use
that device before the guest actually releases it, we are in big
trouble. To avoid this, we already added a loop which waits up to 10
seconds until the device is actually released before we do anything else
with that device. But we only added this loop for managed PCI devices
before we try reattach them back to the host.
However, we need to wait even for non-managed devices. We don't reattach
them automatically, but we still want to prevent the host from using it.
This was revealed thanks to sVirt: when we relabel sysfs files
corresponding to the PCI device before the guest finished releasing the
device, qemu is no longer allowed to access those files and if it wants
(as a result of guest's request) to write anything to them, it just
exits, which kills the guest.
This is not a proper fix and needs some further work both on libvirt and
qemu side in the future.
Fix the error checking to use the return value from brAddTap() instead
of checking the current errno value which might have been changed by
clean up calls inside of brAddTap().
Signed-off-by: Doug Goldstein <cardoe@gentoo.org>
Added a more detailed error message when adding a tap devices fails and
the kernel is missing tun support.
Signed-off-by: Doug Goldstein <cardoe@gentoo.org>
the followup on the boot=on problem, basically it's not needed to
specify it when booting out of IDE devices when using KVM
* src/qemu/qemu_conf.c: do not use boot=on for IDE devices
* tests/qemuxml2argvdata/qemuxml2argv*.args: this changes the output
for 5 of the tests
Patch version revamped by Eric Blake <eblake@redhat.com> of Jiri
Denemark <jdenemar@redhat.com> original patch
When attaching a PCI device which doesn't explicitly set its PCI
address, libvirt allocates the address automatically. The problem is
that when checking which PCI address is unused, we only check for those
with slot number higher than the highest slot number ever used.
Thus attaching/detaching such device several times in a row (31 is the
theoretical limit, less then 30 tries are enough in practise) makes any
further device attachment fail. Furthermore, attaching a device with
predefined PCI address to 0:0:31 immediately forbids attachment of any
PCI device without explicit address.
This patch changes the logic so that we always check all PCI addresses
before we say there is no PCI address available.
Modifications from v1: revert back to remembering the last slot
reserved, but allow wraparound to not be limited by the end.
In this way, slots are still assigned in the same order as
before the patch, rather than filling in the gaps closest to
0 and risking making windows guests mad.
* src/qemu/qemu_conf.c: fix pci reservation code to do a round-robbin
check of all available PCI splot availability before failing.
Basically the 'boot=on' boot selection device is something present in
KVM but not in upstream QEmu, as a result if we boot a QEmu domain
without KVM acceleration we must disable boot=on ... even if the front
end kvm binary expose that capability in the help page.
* src/qemu/qemu_conf.c: in qemudBuildCommandLine if -no-kvm
is passed, then deactivate QEMUD_CMD_FLAG_DRIVE_BOOT
ADD_ARG_LIT should only be used for literal arguments,
since it duplicates the memory. Since virBufferContentAndReset
is already allocating memory, we should only use ADD_ARG.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
If detecting the FLR flag of a pci device fails, then we
could run into the situation of trying to close a file
descriptor twice, once in pciInitDevice() and once in pciFreeDevice().
Fix that by removing the pciCloseConfig() in pciInitDevice() and
just letting pciFreeDevice() handle it.
Thanks to Chris Wright for pointing out this problem.
While we are at it, fix an error check. While it would actually
work as-is (since success returns 0), it's still more clear to
check for < 0 (as the rest of the code does).
Signed-off-by: Chris Lalancette <clalance@redhat.com>
All <console> devices now export a <target> type attribute. QEMU defaults
to 'serial', UML defaults to 'uml, xen can be either 'serial' or 'xen'
depending on fullvirt. Understandably there is lots of test fallout.
This will be used to differentiate between a serial vs. virtio console for
QEMU.
Signed-off-by: Cole Robinson <crobinso@redhat.com>
targetType only tracks the actual <target> format we are parsing. Currently
we only fill abide this value for channel devices.
Signed-off-by: Cole Robinson <crobinso@redhat.com>
There is actually a difference between the character device type (serial,
parallel, channel, ...) and the target type (virtio, guestfwd). Currently
they are awkwardly conflated.
Start to pull them apart by renaming targetType -> deviceType. This is
an entirely mechanical change.
Signed-off-by: Cole Robinson <crobinso@redhat.com>
QEMU has had two different syntax for disk cache options
Old: on|off
New: writeback|writethrough|none
QEMU recently added another 'unsafe' option which broke the
libvirt check. We can avoid this & future breakage, if we
do a negative check for the old syntax, instead of a positive
check for the new syntax
* src/qemu/qemu_conf.c: Invert cache option check
Add a new element to the <os> block:
<bootmenu enable="yes|no"/>
Which maps to -boot,menu=on|off on the QEMU command line.
I decided to use an explicit 'enable' attribute rather than just make the
bootmenu element boolean. This allows us to treat lack of a bootmenu element
as 'use hypervisor default'.
When doing a PCI secondary bus reset, we must be sure that there are no
active devices on the same bus segment. The active device tracking is
designed to only track host devices that are active in use by guests.
This ignores host devices that are actively in use by the host. So the
current logic will reset host devices.
Switch this logic around and allow sbus reset when we are assigning all
devices behind a bridge to the same guest at guest startup or as a result
of a single attach-device command.
* src/util/pci.h: change signature of pciResetDevice to add an
inactive devices list
* src/qemu/qemu_driver.c src/xen/xen_driver.c: use (or not) the new
functionality of pciResetDevice() depending on the place of use
* src/util/pci.c: implement the interface and logic changes
- src/qemu/qemu_driver.c: Eliminate code duplication by using the new
helpers qemuPrepareHostdevPCIDevices and qemuDomainReAttachHostdevDevices.
This reduces the number of open coded calls to pciResetDevice.
- src/qemu/qemu_driver.c: These new helpers take hostdev list and count
directly rather than getting them indirectly from domain definition.
This will allow reuse for the attach-device case.
- src/qemu/qemu_driver.c: Update qemuGetPciHostDeviceList to take a
hostdev list and count directly, rather than getting this indirectly
from domain definition. This will allow reuse for the attach-device case.
Thanks to DV for knocking together the Relax-NG changes
quickly for me.
Changes since v1:
- Change the domain.rng to correspond to the new schema
- Don't allocate caps->ns in testQemuCapsInit since it is a static table
Changes since v2:
- Change domain.rng to add restrictions on allowed environment names
Changes since v3:
- Remove a bogus comment in the tests
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Implement the qemu driver's virDomainQemuMonitorCommand
and hook it into the API entry point.
Changes since v1:
- Rename the (external) qemuMonitorCommand to qemuDomainMonitorCommand
- Add virCheckFlags to qemuDomainMonitorCommand
Changes since v2:
- Drop ATTRIBUTE_UNUSED from the flags
Changes since v3:
- Add a flag to priv so we only print out monitor command warning once. Note
that this has not been plumbed into qemuDomainObjPrivateXMLFormat or
qemuDomainObjPrivateXMLParse, which means that if you run a monitor command,
restart libvirtd, and then run another monitor command, you may get an
an erroneous VIR_INFO. It's a pretty minor matter, and I didn't think it
warranted the additional code.
- Add BeginJob/EndJob calls around EnterMonitor/ExitMonitor
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Add the library entry point for the new virDomainQemuMonitorCommand()
entry point. Because this is not part of the "normal" libvirt API,
it gets its own header file, library file, and will eventually
get its own over-the-wire protocol later in the series.
Changes since v1:
- Go back to using the virDriver table for qemuDomainMonitorCommand, due to
linking issues
- Added versioning information to the libvirt-qemu.so
Changes since v2:
- None
Changes since v3:
- Add LGPL header to libvirt-qemu.c
- Make virLibConnError and virLibDomainError macros instead of function calls
Changes since v4:
- Move exported symbols to libvirt_qemu.syms
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Now that we have the ability to specify arbitrary qemu
command-line parameters in the XML, use it to handle unknown
command-line parameters when doing a native-to-xml conversion.
Changes since v1:
- Rename num_extra to num_args
- Fix up a memory leak on an error path
Changes since v2:
- Add a VIR_WARN when adding the argument via qemu:arg
Changes since v3:
- None
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Implement the qemu hooks for XML namespace data. This
allows us to specify a qemu XML namespace, and then
specify:
<qemu:commandline>
<qemu:arg value='arg'/>
<qemu:env name='name' value='value'/>
</qemu:commandline>
In the domain XML.
Changes since v1:
- Change the <qemu:arg>arg</qemu:arg> XML to <qemu:arg value='arg'/> XML
- Fix up some memory leaks in qemuDomainDefNamespaceParse
- Rename num_extra and extra to num_args and args, respectively
- Fixed up some error messages
- Make sure to escape user-provided data in qemuDomainDefNamespaceFormatXML
Changes since v2:
- Add checking to ensure environment variable names are valid
- Invert the logic in qemuDomainDefNamespaceFormatXML to return early
Changes since v3:
- Change strspn() to c_isalpha() check of first letter of environment variable
Signed-off-by: Chris Lalancette <clalance@redhat.com>
A Linux software bridge will assume the MAC address of the enslaved
interface with the numerically lowest MAC addr. When the bridge
changes MAC address there is a period of network blackout, so a
change should be avoided. The kernel gives TAP devices a completely
random MAC address. Occassionally the random TAP device MAC is lower
than that of the physical interface (eth0, eth1etc) that is enslaved,
causing the bridge to change its MAC.
This change sets an explicit MAC address for all TAP devices created
using the configured MAC from the XML, but with the high byte set
to 0xFE. This should ensure TAP device MACs are higher than any
physical interface MAC.
* src/qemu/qemu_conf.c, src/uml/uml_conf.c: Pass in a MAC addr
for the TAP device with high byte set to 0xFE
* src/util/bridge.c, src/util/bridge.h: Set a MAC when creating
the TAP device to override random MAC
The PCI slot 1 must be reserved at all times, since PIIX3 is
always present, even if no IDE device is in use for guest disks
* src/qemu/qemu_conf.c: Always reserve slot 1 for PIIX3
virFileOperation previously returned 0 on success, or the value of
errno on failure. Although there are other functions in libvirt that
use this convention, the preferred (and more common) convention is to
return 0 on success and -errno (or simply -1 in some cases) on
failure. This way the check for failure is always (ret < 0).
* src/util/util.c - change virFileOperation and virFileOperationNoFork to
return -errno on failure.
* src/storage/storage_backend.c, src/qemu/qemu_driver.c
- change the hook functions passed to virFileOperation to return
-errno on failure.
To try and ensure that people upgrading from old QEMU get guests
with the same PCI device ordering, change the way we assign addrs
to match QEMU's default order. This should make Windows less
annoyed.
* src/qemu/qemu_conf.c: Follow QEMU's default PCI ordering
logic when assigning addresses
* tests/*.args: Update for changed PCI addresses
To allow compatibility with older QEMU PCI device slot assignment
it is necessary to explicitly track the balloon device in the
XML. This introduces a new device
<memballoon model='virtio|xen'/>
It can also have a PCI address, auto-assigned if necessary.
The memballoon will be automatically added to all Xen and QEMU
guests by default.
* docs/schemas/domain.rng: Add <memballoon> element
* src/conf/domain_conf.c, src/conf/domain_conf.h: parsing
and formatting for memballoon device. Always add a memory
balloon device to Xen/QEMU if none exists in XML
* src/libvirt_private.syms: Export memballoon model APIs
* src/qemu/qemu_conf.c, src/qemu/qemu_conf.h: Honour the
PCI device address in memory balloon device
* tests/*: Update to test new functionality
The first VGA and IDE devices need to have fixed PCI address
reservations. Currently this is handled inline with the other
non-primary VGA/IDE devices. The fixed virtio balloon device
at slot 3, ensures auto-assignment skips the slots 1/2. The
virtio address will shortly become configurable though. This
means the reservation of fixed slots needs to be done upfront
to ensure that they don't get re-used for other devices.
This is more or less reverting the previous changeset:
commit 83acdeaf17
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Wed Feb 3 16:11:29 2010 +0000
Fix restore of QEMU guests with PCI device reservation
The difference is that this time, instead of unconditionally
reserving the address, we only reserve the address if it was
initially type=none. Addresses of type=pci were handled
earlier in process by qemuDomainPCIAddressSetCreate(). This
ensures restore step doesn't have problems
* src/qemu/qemu_conf.c: Reserve first VGA + IDE address
upfront
The VIR_ERR_NO_SUPPORT refers to an API which is not implemented.
There is a separate VIR_ERR_CONFIG_UNSUPPORTED for XML config
options that are not available with the current hypervisor.
* src/qemu/qemu_conf.c, src/qemu/qemu_driver.c: Remove
many VIR_ERR_NO_SUPPORT replace with VIR_ERR_CONFIG_UNSUPPORTED
If you try to execute two concurrent migrations p2p
from A->B and B->A, the two libvirtd's will deadlock
trying to perform the migrations. The reason for this is
that in p2p migration, the libvirtd's are responsible for
making the RPC Prepare, Migrate, and Finish calls. However,
they are currently holding the driver lock while doing so,
which basically guarantees deadlock in this scenario.
This patch fixes the situation by adding
qemuDomainObjEnterRemoteWithDriver and
qemuDomainObjExitRemoteWithDriver helper methods. The Enter
take an additional object reference, then drops both the
domain object lock and the driver lock. The Exit takes
both the driver and domain object lock, then drops the
reference. Adding calls to these Enter and Exit helpers
around remote calls in the various migration methods
seems to fix the problem for me in testing.
This should make the situation safe. The additional domain
object reference ensures that the domain object won't disappear
while this operation is happening. The BeginJob that is called
inside of qemudDomainMigratePerform ensures that we can't execute a
second migrate (or shutdown, or save, etc) job while the
migration is active. Finally, the additional check on the state
of the vm after we reacquire the locks ensures that we can't
be surprised by an external event (domain crash, etc).
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Record a default driver name/type in capabilities struct. Use this
when parsing disks if value is not set in XML config.
* src/conf/capabilities.h: Record default driver name/type for disks
* src/conf/domain_conf.c: Fallback to default driver name/type
when parsing disks
* src/qemu/qemu_driver.c: Set default driver name/type to raw
Disk format probing is now disabled by default. A new config
option in /etc/qemu/qemu.conf will re-enable it for existing
deployments where this causes trouble
The implementation of security driver callbacks often needs
to access the security driver object. Currently only a handful
of callbacks include the driver object as a parameter. Later
patches require this is many more places.
* src/qemu/qemu_driver.c: Pass in the security driver object
to all callbacks
* src/qemu/qemu_security_dac.c, src/qemu/qemu_security_stacked.c,
src/security/security_apparmor.c, src/security/security_driver.h,
src/security/security_selinux.c: Add a virSecurityDriverPtr
param to all security callbacks
Update the QEMU cgroups code, QEMU DAC security driver, SELinux
and AppArmour security drivers over to use the shared helper API
virDomainDiskDefForeachPath().
* src/qemu/qemu_driver.c, src/qemu/qemu_security_dac.c,
src/security/security_selinux.c, src/security/virt-aa-helper.c:
Convert over to use virDomainDiskDefForeachPath()
Require the disk image to be passed into virStorageFileGetMetadata.
If this is set to VIR_STORAGE_FILE_AUTO, then the format will be
resolved using probing. This makes it easier to control when
probing will be used
* src/qemu/qemu_driver.c, src/qemu/qemu_security_dac.c,
src/security/security_selinux.c, src/security/virt-aa-helper.c:
Set VIR_STORAGE_FILE_AUTO when calling virStorageFileGetMetadata.
* src/storage/storage_backend_fs.c: Probe for disk format before
calling virStorageFileGetMetadata.
* src/util/storage_file.h, src/util/storage_file.c: Remove format
from virStorageFileMeta struct & require it to be passed into
method.
