Re: [libvirt] [PATCH v2 1/3] libxl: implement NUMA capabilities reporting

Starting from Xen 4.2, libxl has all the bits and pieces in place for retrieving an adequate amount of information about the host NUMA topology. It is therefore possible, after a bit of shuffling, to arrange those information in the way libvirt wants to present them to the outside world. Therefore, with this patch, the <topology> section of the host capabilities is properly populated, when running on Xen, so that we can figure out whether or not we're running on a NUMA host, and what its characteristics are. [raistlin@Zhaman ~]$ sudo virsh --connect xen:/// capabilities <capabilities> <host> <cpu> .... <topology> <cells num='2'> <cell id='0'> <memory unit='KiB'>6291456</memory> <cpus num='8'> <cpu id='0' socket_id='1' core_id='0' siblings='0-1'/> <cpu id='1' socket_id='1' core_id='0' siblings='0-1'/> <cpu id='2' socket_id='1' core_id='1' siblings='2-3'/> <cpu id='3' socket_id='1' core_id='1' siblings='2-3'/> <cpu id='4' socket_id='1' core_id='9' siblings='4-5'/> <cpu id='5' socket_id='1' core_id='9' siblings='4-5'/> <cpu id='6' socket_id='1' core_id='10' siblings='6-7'/> <cpu id='7' socket_id='1' core_id='10' siblings='6-7'/> </cpus> </cell> <cell id='1'> <memory unit='KiB'>6881280</memory> <cpus num='8'> <cpu id='8' socket_id='0' core_id='0' siblings='8-9'/> <cpu id='9' socket_id='0' core_id='0' siblings='8-9'/> <cpu id='10' socket_id='0' core_id='1' siblings='10-11'/> <cpu id='11' socket_id='0' core_id='1' siblings='10-11'/> <cpu id='12' socket_id='0' core_id='9' siblings='12-13'/> <cpu id='13' socket_id='0' core_id='9' siblings='12-13'/> <cpu id='14' socket_id='0' core_id='10' siblings='14-15'/> <cpu id='15' socket_id='0' core_id='10' siblings='14-15'/> </cpus> </cell> </cells> </topology> </host> .... Signed-off-by: Dario Faggioli <dario.faggioli(a)citrix.com&gt; --- Changes from v1: * fixed a typo in the commit message, as requested during review; * fixed coding style (one function parameters per line and no spaces between variable definitions), as requested during review; * avoid zero-filling memory after VIR_ALLOC_N(), since it does that already, as requested during review; * improved out of memory error reporting, as requested during review; * libxlMakeNumaCapabilities() created, accommodating all the NUMA related additions, instead of having them within libxlMakeCapabilitiesInternal(), as suggested during review. --- src/libxl/libxl_conf.c | 141 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+), 1 deletion(-) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index e170357..7515995 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -161,6 +161,115 @@ libxlBuildCapabilities(virArch hostarch, } static virCapsPtr +libxlMakeNumaCapabilities(libxl_numainfo *numa_info, + int nr_nodes, + libxl_cputopology *cpu_topo, + int nr_cpus, + virCapsPtr caps) +{ + virCapsHostNUMACellCPUPtr *cpus = NULL; + int *nr_cpus_node = NULL; + bool numa_failed = false; + int i;