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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.
cc2d49f9be
https://bugzilla.redhat.com/show_bug.cgi?id=1249981 When qemuDomainPinIOThread was added in commit id 'fb562614', a check for the IOThread capability was not needed since a check for iothreadpids covered the condition where the support for IOThreads was not present. The iothreadpids array was only created if qemuProcessDetectIOThreadPIDs was able to query the monitor for IOThreads. It would only do that if the QEMU_CAPS_OBJECT_IOTHREAD capability was set. However, when iothreadids were added in commit id '8d4614a5' and the check for iothreadpids was replaced by a search through the iothreadids[] array for the matching iothread_id that left open the possibility that an iothreadids[] array was defined, but the entries essentially pointed to elements with only the 'iothread_id' defined leaving the 'thread_id' value of 0 and eventually the cpumap entry of NULL. This was because, the original IOThreads commit id '72edaae7' only checked if IOThreads were defined and if the emulator had the IOThreads capability, then IOThread objects were added at startup. The "capability failure" check was only done when a disk was assigned to an IOThread in qemuCheckIOThreads. This was because the initial implementation had no way to dynamically add IOThreads, but it was possible to dynamically add a disk to the domain. So the decision was if the domain supported it, then add the IOThread objects. Then if a disk with an IOThread defined was added, it could check the capability and fail to add if not there. This just meant the 'iothreads' value was essentially ignored. Eventually commit id 'a27ed6e7' allowed for the dynamic addition and deletion of IOThread objects. So it was no longer necessary to generate IOThread objects to dynamically attach a disk to. However, the startup and disk check code was not modified to reflect this. This patch will move the capability failure check to when IOThread objects are being added to the command line. Thus a domain that has IOThreads defined will not be started if the emulator doesn't support the capability. This means when qemuCheckIOThreads is called to add a disk, it's no longer necessary to check the capability. Instead the code can use the IOThreadFind call to indicate that the IOThread doesn't exist. Finally because it could be possible to have a domain running with the iothreadids[] defined prior to this change if libvirtd is restarted each having mostly empty elements, qemuProcessDetectIOThreadPIDs will check if there are niothreadids when the QEMU_CAPS_OBJECT_IOTHREAD capability check fails and remove the elements and array if it exists. With these changes in place, it turns out the cputune-numatune test was failing because the right bit wasn't set in the test. So used the opportunity to fix that and create a test that would expect to fail with some sort of iothreads defined and used, but not having the correct capability. |
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| build-aux | ||
| daemon | ||
| docs | ||
| examples | ||
| gnulib | ||
| include | ||
| m4 | ||
| po | ||
| src | ||
| tests | ||
| tools | ||
| .ctags | ||
| .dir-locals.el | ||
| .gitignore | ||
| .gitmodules | ||
| .mailmap | ||
| AUTHORS.in | ||
| autobuild.sh | ||
| autogen.sh | ||
| bootstrap | ||
| bootstrap.conf | ||
| cfg.mk | ||
| ChangeLog-old | ||
| config-post.h | ||
| configure.ac | ||
| COPYING | ||
| COPYING.LESSER | ||
| HACKING | ||
| libvirt-admin.pc.in | ||
| libvirt-lxc.pc.in | ||
| libvirt-qemu.pc.in | ||
| libvirt.pc.in | ||
| libvirt.spec.in | ||
| Makefile.am | ||
| Makefile.nonreentrant | ||
| mingw-libvirt.spec.in | ||
| README | ||
| README-hacking | ||
| run.in | ||
| TODO | ||
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>