[Xen-devel] [PATCH 2 of 3] libxl: allow for specifying the CPU affinity in the config file.

[Dario Faggioli <raistlin@xxxxxxxx>]

Enable CPU affinity specification in a VM's config file with the
exact syntax `xl vcpu-pin' provides.

Signed-off-by: Dario Faggioli <dario.faggioli@xxxxxxxxxx>

diff -r 9ce68a4036b1 tools/libxl/libxl_create.c
--- a/tools/libxl/libxl_create.c        Wed Jan 11 17:38:04 2012 +0000
+++ b/tools/libxl/libxl_create.c        Wed Jan 11 17:40:45 2012 +0000
@@ -78,6 +78,8 @@ int libxl_init_build_info(libxl_ctx *ctx
     memset(b_info, '\0', sizeof(*b_info));
     b_info->max_vcpus = 1;
     b_info->cur_vcpus = 1;
+    if (libxl_cpumap_alloc(ctx, &b_info->cpumap))
+        return ERROR_NOMEM;
     b_info->max_memkb = 32 * 1024;
     b_info->target_memkb = b_info->max_memkb;
     b_info->disable_migrate = 0;
diff -r 9ce68a4036b1 tools/libxl/libxl_dom.c
--- a/tools/libxl/libxl_dom.c   Wed Jan 11 17:38:04 2012 +0000
+++ b/tools/libxl/libxl_dom.c   Wed Jan 11 17:40:45 2012 +0000
@@ -72,8 +72,14 @@ int libxl__build_pre(libxl__gc *gc, uint
               libxl_domain_build_info *info, libxl__domain_build_state *state)
 {
     libxl_ctx *ctx = libxl__gc_owner(gc);
-    int tsc_mode;
+    int i, tsc_mode;
     xc_domain_max_vcpus(ctx->xch, domid, info->max_vcpus);
+    for (i = 0; i < info->max_vcpus; i++) {
+        if (libxl_set_vcpuaffinity(ctx, domid, i, &info->cpumap) == -1) {
+                LIBXL__LOG(ctx, LIBXL__LOG_WARNING, "libxl_set_vcpuaffinity 
failed. "
+                           "Going ahead without setting affinity for cpu 
%d.\n", i);
+        }
+    }
     xc_domain_setmaxmem(ctx->xch, domid, info->target_memkb + 
LIBXL_MAXMEM_CONSTANT);
     if (info->type == LIBXL_DOMAIN_TYPE_PV)
         xc_domain_set_memmap_limit(ctx->xch, domid,
diff -r 9ce68a4036b1 tools/libxl/libxl_types.idl
--- a/tools/libxl/libxl_types.idl       Wed Jan 11 17:38:04 2012 +0000
+++ b/tools/libxl/libxl_types.idl       Wed Jan 11 17:40:45 2012 +0000
@@ -162,6 +162,7 @@ libxl_domain_create_info = Struct("domai
 libxl_domain_build_info = Struct("domain_build_info",[
     ("max_vcpus",       integer),
     ("cur_vcpus",       integer),
+    ("cpumap",          libxl_cpumap),
     ("tsc_mode",        libxl_tsc_mode),
     ("max_memkb",       uint32),
     ("target_memkb",    uint32),
diff -r 9ce68a4036b1 tools/libxl/xl_cmdimpl.c
--- a/tools/libxl/xl_cmdimpl.c  Wed Jan 11 17:38:04 2012 +0000
+++ b/tools/libxl/xl_cmdimpl.c  Wed Jan 11 17:40:45 2012 +0000
@@ -288,16 +288,24 @@ static void dolog(const char *file, int 
         libxl_write_exactly(NULL, logfile, s, rc, NULL, NULL);
 }
 
+static void print_bitmap(uint8_t *map, int maplen, FILE *stream);
+
 static void printf_info(int domid,
                         libxl_domain_config *d_config,
                         libxl_device_model_info *dm_info)
 {
-    int i;
+    int i, nr_cpus = -1;
     libxl_dominfo info;
+    libxl_physinfo physinfo;
 
     libxl_domain_create_info *c_info = &d_config->c_info;
     libxl_domain_build_info *b_info = &d_config->b_info;
 
+    if (libxl_get_physinfo(ctx, &physinfo) == 0)
+        nr_cpus = physinfo.nr_cpus;
+    else
+        fprintf(stderr, "libxl_physinfo failed.\n");
+
     printf("(domain\n\t(domid %d)\n", domid);
     printf("\t(create_info)\n");
     printf("\t(hvm %d)\n", c_info->type == LIBXL_DOMAIN_TYPE_HVM);
@@ -328,6 +336,9 @@ static void printf_info(int domid,
 
     printf("\t(build_info)\n");
     printf("\t(max_vcpus %d)\n", b_info->max_vcpus);
+    printf("\t(CPU affinity ");
+    print_bitmap(b_info->cpumap.map, nr_cpus, stdout);
+    printf(")\n");
     printf("\t(tsc_mode %s)\n", libxl_tsc_mode_to_string(b_info->tsc_mode));
     printf("\t(max_memkb %d)\n", b_info->max_memkb);
     printf("\t(target_memkb %d)\n", b_info->target_memkb);
@@ -569,6 +580,8 @@ static void split_string_into_string_lis
     free(s);
 }
 
+static int vcpupin_parse(char *cpu, libxl_cpumap *cpumap);
+
 static void parse_config_data(const char *configfile_filename_report,
                               const char *configfile_data,
                               int configfile_len,
@@ -661,6 +674,13 @@ static void parse_config_data(const char
     if (!xlu_cfg_get_long (config, "maxvcpus", &l, 0))
         b_info->max_vcpus = l;
 
+    if (!xlu_cfg_get_string (config, "cpus", &buf, 0)) {
+        char *buf2 = strdup(buf);
+        vcpupin_parse(buf2, &b_info->cpumap);
+    } else {
+        memset(b_info->cpumap.map, -1, b_info->cpumap.size);
+    }
+
     if (!xlu_cfg_get_long (config, "memory", &l, 0)) {
         b_info->max_memkb = l * 1024;
         b_info->target_memkb = b_info->max_memkb;

-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-------------------------------------------------------------------
Dario Faggioli, http://retis.sssup.it/people/faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)
PhD Candidate, ReTiS Lab, Scuola Superiore Sant'Anna, Pisa (Italy)

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