Re: [libvirt] virDomainGetMaxVcpus does not work as expected

Hi. Any opinions on this? At Thu, 13 Feb 2014 14:50:08 +0100, Claudio Bley wrote: > > Hi. > > When calling virDomainGetMaxVcpus > (http://libvirt.org/html/libvirt-libvirt.html#virDomainGetMaxVcpus) on > an inactive domain, I receive this error: > > scala> res2.getMaxVcpus() > libvirt: Domain Config error : Requested operation is not valid: domain is not running > org.libvirt.LibvirtException: Requested operation is not valid: domain is not running > at org.libvirt.ErrorHandler.processError(ErrorHandler.java:31) > at org.libvirt.ErrorHandler.processError(ErrorHandler.java:46) > at org.libvirt.Domain.getMaxVcpus(Domain.java:571) > at .<init>(<console>:13) > ... > > (this is from Java, but that doesn't matter) > > The docs say: > >> If the guest is inactive, this is basically the same as >> virConnectGetMaxVcpus(). If the guest is running this will reflect >> the maximum number of virtual CPUs the guest was booted with. > > But, apparently, all the driver implementations for > virDomainGetMaxVcpus forward to > <driver>DomainGetVcpusFlags(.., VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_VCPU_MAXIMUM). > _______________________________,~~~~~~~~~~~~~~~~~~~~~~ > > > $ git grep --show-function 'GetVcpusFlags.*AFFECT_LIVE' > src/esx/esx_driver.c=esxDomainGetMaxVcpus(virDomainPtr domain) > src/esx/esx_driver.c: return esxDomainGetVcpusFlags(domain, (VIR_DOMAIN_AFFECT_LIVE | > src/openvz/openvz_driver.c=static int openvzDomainGetMaxVcpus(virDomainPtr dom) > src/openvz/openvz_driver.c: return openvzDomainGetVcpusFlags(dom, (VIR_DOMAIN_AFFECT_LIVE | > src/qemu/qemu_driver.c=qemuDomainGetMaxVcpus(virDomainPtr dom) > src/qemu/qemu_driver.c: return qemuDomainGetVcpusFlags(dom, (VIR_DOMAIN_AFFECT_LIVE | > src/test/test_driver.c=testDomainGetMaxVcpus(virDomainPtr domain) > src/test/test_driver.c: return testDomainGetVcpusFlags(domain, (VIR_DOMAIN_AFFECT_LIVE | > src/vbox/vbox_tmpl.c=vboxDomainGetMaxVcpus(virDomainPtr dom) > src/vbox/vbox_tmpl.c: return vboxDomainGetVcpusFlags(dom, (VIR_DOMAIN_AFFECT_LIVE | > > > AFAICS, this was introduced with > > commit 50c51f13e2af04afac46e181c4ed62581545a488 > Author: Eric Blake <eblake(a)redhat.com&gt; > Date: Mon Sep 27 16:37:53 2010 -0600 > > vcpu: make old API trivially wrap to new API > > > Whereas the function's contract was documented earlier by > > commit b412cfadb502c76df095c2c4548c27abf7c4873f > Author: Daniel Veillard <veillard(a)redhat.com&gt; > Date: Thu Mar 8 08:31:07 2007 +0000 > > > To be honest, I'm not sure whether this worked as described at some > time in the past _at all_. > > How to fix this? Change the documentation or the flag? >