Re: [libvirt] [PATCH V2] Xen: support maxvcpus in xm and xl config

On 15.12.2015 23:20, Jim Fehlig wrote: > From: Ian Campbell <ian.campbell(a)citrix.com&gt; > > xend prior to 4.0 understands vcpus as maxvcpus and vcpu_avail > as a bit map of which cpus are online (default is all). > > xend from 4.0 onwards understands maxvcpus as maxvcpus and > vcpus as the number which are online (from 0..N-1). The > upstream commit (68a94cf528e6 "xm: Add maxvcpus support") > claims that if maxvcpus is omitted then the old behaviour > (i.e. obeying vcpu_avail) is retained, but AFAICT it was not, > in this case vcpu==maxcpus==online cpus. This is good for us > because handling anything else would be fiddly. > > This patch changes parsing of the virDomainDef maxvcpus and vcpus > entries to use the corresponding 'maxvcpus' and 'vcpus' settings > from xm and xl config. It also drops use of the old Xen 3.x > 'vcpu_avail' setting. > > The change also removes the maxvcpus limit of MAX_VIRT_VCPUS (since > maxvcpus is simply a count, not a bit mask), which is particularly > crucial on ARM where MAX_VIRT_CPUS == 1 (since all guests are > expected to support vcpu placement, and therefore only the boot > vcpu's info lives in the shared info page). > > Existing tests adjusted accordingly, and new tests added for the > 'maxvcpus' setting. > > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > > This is a respin of Ian's patch [1] to support parsing/formatting of the > 'maxvcpus' xm and xl config setting. It goes a bit further and removes > the old Xen 3.x 'vcpu_avail' setting and lifts the maxvcpus limit of > MAX_VIRT_CPUS entirely. > > The patch is based on my recent series [2] removing xend config version from > the codebase. > > [1] https://www.redhat.com/archives/libvir-list/2015-November/msg01155.html > [2] https://www.redhat.com/archives/libvir-list/2015-December/msg00616.html > > > src/xenconfig/xen_common.c | 25 +++++++++++---------- > tests/xlconfigdata/test-paravirt-maxvcpus.cfg | 13 +++++++++++ > tests/xlconfigdata/test-paravirt-maxvcpus.xml | 28 ++++++++++++++++++++++++ > tests/xlconfigtest.c | 1 + > tests/xmconfigdata/test-paravirt-maxvcpus.cfg | 13 +++++++++++ > tests/xmconfigdata/test-paravirt-maxvcpus.xml | 31 +++++++++++++++++++++++++++ > tests/xmconfigdata/test-paravirt-vcpu.cfg | 4 ++-- > tests/xmconfigtest.c | 1 + > 8 files changed, 101 insertions(+), 15 deletions(-) ACK