b7f7f07542
When detaching a device, the following race condition may happen: Once qemuDomainSignalDeviceRemoval() marks the device for removal, it returns true, which means it is the caller that marked the device for removal is going to remove the device from domain definition. But qemuDomainWaitForDeviceRemoval() may still receive timeout from virDomainObjWaitUntil() which is implemented by pthread_cond_timedwait() due to an unavoidable race between the expiration of the timeout and the predicate state(priv->unplug.alias) change. And then qemuDomainWaitForDeviceRemoval() will return 0, thus the caller will not remove the device from domain definition. In this situation, the device is still present in the domain definition but doesn't exist in qemu anymore. Worse, there is no way to remove it from the domain definition. Solution is to recheck the value of priv->unplug.alias to determine who is going to remove the device from domain definition. Signed-off-by: zuo boqun <zuoboqun@baidu.com> Reviewed-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Peter Krempa <pkrempa@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser
General Public License, version 2.1 (or later). Some parts of the code
that are not part of the C library may have the more restrictive GNU
General Public License, version 2.0 (or later). See the files
COPYING.LESSER and COPYING for full license
terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: