diff options
| -rw-r--r-- | docs/man/xl.cfg.pod.5 | 26 | ||||
| -rw-r--r-- | tools/libxl/xl_cmdimpl.c | 44 |
2 files changed, 63 insertions, 7 deletions
diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5 index 64baf38f74..832bae4cb9 100644 --- a/docs/man/xl.cfg.pod.5 +++ b/docs/man/xl.cfg.pod.5 @@ -108,9 +108,25 @@ created online and the remainder will be offline. =item B<cpus="CPU-LIST"> List of which cpus the guest is allowed to use. Default behavior is -`all cpus`. A list of cpus may be specified as follows: `cpus="0-3,5,^1"` -(all vcpus will run on cpus 0,2,3,5), or `cpus=["2", "3"]` (all vcpus -will run on cpus 2 and 3). +`all cpus`. A C<CPU-LIST> may be specified as follows: + +=over 4 + +=item "all" + +To allow all the vcpus of the guest to run on all the cpus on the host. + +=item "0-3,5,^1" + +To allow all the vcpus of the guest to run on cpus 0,2,3,5. + +=item ["2", "3"] (or [2, 3]) + +To ask for specific vcpu mapping. That means (in this example), vcpu #0 +of the guest will run on cpu #2 of the host and vcpu #1 of the guest will +run on cpu #3 of the host. + +=back =item B<cpu_weight=WEIGHT> @@ -951,10 +967,6 @@ XXX XXX -=item B<cpus=XXX> - -XXX - =item B<maxmem=NUMBER> XXX diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c index 5fc5cde2d2..edfe462ab6 100644 --- a/tools/libxl/xl_cmdimpl.c +++ b/tools/libxl/xl_cmdimpl.c @@ -71,6 +71,8 @@ static uint32_t domid; static const char *common_domname; static int fd_lock = -1; +/* Stash for specific vcpu to pcpu mappping */ +static int *vcpu_to_pcpu; static const char savefileheader_magic[32]= "Xen saved domain, xl format\n \0 \r"; @@ -630,6 +632,21 @@ static void parse_config_data(const char *configfile_filename_report, exit(1); } + /* Prepare the array for single vcpu to pcpu mappings */ + vcpu_to_pcpu = xmalloc(sizeof(int) * b_info->max_vcpus); + memset(vcpu_to_pcpu, -1, sizeof(int) * b_info->max_vcpus); + + /* + * Idea here is to let libxl think all the domain's vcpus + * have cpu affinity with all the pcpus on the list. + * It is then us, here in xl, that matches each single vcpu + * to its pcpu (and that's why we need to stash such info in + * the vcpu_to_pcpu array now) after the domain has been created. + * Doing it like this saves the burden of passing to libxl + * some big array hosting the single mappings. Also, using + * the cpumap derived from the list ensures memory is being + * allocated on the proper nodes anyway. + */ libxl_cpumap_set_none(&b_info->cpumap); while ((buf = xlu_cfg_get_listitem(cpus, n_cpus)) != NULL) { i = atoi(buf); @@ -638,6 +655,8 @@ static void parse_config_data(const char *configfile_filename_report, exit(1); } libxl_cpumap_set(&b_info->cpumap, i); + if (n_cpus < b_info->max_vcpus) + vcpu_to_pcpu[n_cpus] = i; n_cpus++; } } @@ -1714,6 +1733,31 @@ start: if ( ret ) goto error_out; + /* If single vcpu to pcpu mapping was requested, honour it */ + if (vcpu_to_pcpu) { + libxl_cpumap vcpu_cpumap; + + libxl_cpumap_alloc(ctx, &vcpu_cpumap); + for (i = 0; i < d_config.b_info.max_vcpus; i++) { + + if (vcpu_to_pcpu[i] != -1) { + libxl_cpumap_set_none(&vcpu_cpumap); + libxl_cpumap_set(&vcpu_cpumap, vcpu_to_pcpu[i]); + } else { + libxl_cpumap_set_any(&vcpu_cpumap); + } + if (libxl_set_vcpuaffinity(ctx, domid, i, &vcpu_cpumap)) { + fprintf(stderr, "setting affinity failed on vcpu `%d'.\n", i); + libxl_cpumap_dispose(&vcpu_cpumap); + free(vcpu_to_pcpu); + ret = ERROR_FAIL; + goto error_out; + } + } + libxl_cpumap_dispose(&vcpu_cpumap); + free(vcpu_to_pcpu); vcpu_to_pcpu = NULL; + } + ret = libxl_userdata_store(ctx, domid, "xl", config_data, config_len); if (ret) { |