Add flag to BaselineCPU API to return detailed CPU features

Currently the virConnectBaselineCPU API does not expose the CPU features
that are part of the CPU's model.  This patch adds a new flag,
VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, that causes the API to explicitly
list all features that are part of that model.

Signed-off-by: Don Dugger <donald.d.dugger@intel.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index 52ac95d722a31d38e5f13dbf59349db5a0e325db..a47e33cc73affc348ad08c488142b22a05af919d 100644 (file)
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -4007,6 +4007,15 @@ int virConnectCompareCPU(virConnectPtr conn,
                          unsigned int flags);
 
 
+/**
+ * virConnectBaselineCPUFlags
+ *
+ * Flags when getting XML description of a computed CPU
+ */
+typedef enum {
+    VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES  = (1 << 0),  /* show all features */
+} virConnectBaselineCPUFlags;
+
 /**
  * virConnectBaselineCPU:
  *

diff --git a/src/cpu/cpu.c b/src/cpu/cpu.c
index 4124354e79b3381871567655638fee6f4e2d1c11..023ce2652a16c9413ecaae6706de62babd866120 100644 (file)
--- a/src/cpu/cpu.c
+++ b/src/cpu/cpu.c
@@ -167,7 +167,7 @@ cpuDecode(virCPUDefPtr cpu,
         return -1;
     }
 
-    return driver->decode(cpu, data, models, nmodels, preferred);
+    return driver->decode(cpu, data, models, nmodels, preferred, 0);
 }
 
 
@@ -276,7 +276,8 @@ char *
 cpuBaselineXML(const char **xmlCPUs,
                unsigned int ncpus,
                const char **models,
-               unsigned int nmodels)
+               unsigned int nmodels,
+               unsigned int flags)
 {
     xmlDocPtr doc = NULL;
     xmlXPathContextPtr ctxt = NULL;
@@ -323,7 +324,7 @@ cpuBaselineXML(const char **xmlCPUs,
         doc = NULL;
     }
 
-    if (!(cpu = cpuBaseline(cpus, ncpus, models, nmodels)))
+    if (!(cpu = cpuBaseline(cpus, ncpus, models, nmodels, flags)))
         goto error;
 
     cpustr = virCPUDefFormat(cpu, 0);
@@ -350,7 +351,8 @@ virCPUDefPtr
 cpuBaseline(virCPUDefPtr *cpus,
             unsigned int ncpus,
             const char **models,
-            unsigned int nmodels)
+            unsigned int nmodels,
+            unsigned int flags)
 {
     struct cpuArchDriver *driver;
     size_t i;
@@ -392,7 +394,7 @@ cpuBaseline(virCPUDefPtr *cpus,
         return NULL;
     }
 
-    return driver->baseline(cpus, ncpus, models, nmodels);
+    return driver->baseline(cpus, ncpus, models, nmodels, flags);
 }
 
 

diff --git a/src/cpu/cpu.h b/src/cpu/cpu.h
index 40034350ae2e38dec72157a634532fb51b63f58d..7f1d4bd027326d9cd751d51a5e98ae0a4b9df66d 100644 (file)
--- a/src/cpu/cpu.h
+++ b/src/cpu/cpu.h
@@ -53,7 +53,8 @@ typedef int
                      const virCPUDataPtr data,
                      const char **models,
                      unsigned int nmodels,
-                     const char *preferred);
+                     const char *preferred,
+                     unsigned int flags);
 
 typedef int
 (*cpuArchEncode)    (virArch arch,
@@ -81,7 +82,8 @@ typedef virCPUDefPtr
 (*cpuArchBaseline)  (virCPUDefPtr *cpus,
                      unsigned int ncpus,
                      const char **models,
-                     unsigned int nmodels);
+                     unsigned int nmodels,
+                     unsigned int flags);
 
 typedef int
 (*cpuArchUpdate)    (virCPUDefPtr guest,
@@ -149,13 +151,15 @@ extern char *
 cpuBaselineXML(const char **xmlCPUs,
                unsigned int ncpus,
                const char **models,
-               unsigned int nmodels);
+               unsigned int nmodels,
+               unsigned int flags);
 
 extern virCPUDefPtr
 cpuBaseline (virCPUDefPtr *cpus,
              unsigned int ncpus,
              const char **models,
-             unsigned int nmodels);
+             unsigned int nmodels,
+             unsigned int flags);
 
 extern int
 cpuUpdate   (virCPUDefPtr guest,

diff --git a/src/cpu/cpu_arm.c b/src/cpu/cpu_arm.c
index 25e25ba361da2f0f81cb466933093a26f6c39c1a..d1b2a99b17479f35198f4a0965b17722dfd34cda 100644 (file)
--- a/src/cpu/cpu_arm.c
+++ b/src/cpu/cpu_arm.c
@@ -44,8 +44,12 @@ ArmDecode(virCPUDefPtr cpu ATTRIBUTE_UNUSED,
           const virCPUDataPtr data ATTRIBUTE_UNUSED,
           const char **models ATTRIBUTE_UNUSED,
           unsigned int nmodels ATTRIBUTE_UNUSED,
-          const char *preferred ATTRIBUTE_UNUSED)
+          const char *preferred ATTRIBUTE_UNUSED,
+          unsigned int flags)
 {
+
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, -1);
+
     return 0;
 }
 

diff --git a/src/cpu/cpu_generic.c b/src/cpu/cpu_generic.c
index 2fe792ff63ba5805207ee01e46f5b972719c57a2..1264da4981932b069fba82003af3a032063a8543 100644 (file)
--- a/src/cpu/cpu_generic.c
+++ b/src/cpu/cpu_generic.c
@@ -113,7 +113,8 @@ static virCPUDefPtr
 genericBaseline(virCPUDefPtr *cpus,
                 unsigned int ncpus,
                 const char **models,
-                unsigned int nmodels)
+                unsigned int nmodels,
+                unsigned int flags)
 {
     virCPUDefPtr cpu = NULL;
     virCPUFeatureDefPtr features = NULL;
@@ -121,6 +122,8 @@ genericBaseline(virCPUDefPtr *cpus,
     unsigned int count;
     size_t i, j;
 
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, NULL);
+
     if (!cpuModelIsAllowed(cpus[0]->model, models, nmodels)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("CPU model %s is not supported by hypervisor"),

diff --git a/src/cpu/cpu_powerpc.c b/src/cpu/cpu_powerpc.c
index 55a41534897d58a959f2391ab773df135a8e4063..647a8a11e21104b919fff7748d5822f2075a205a 100644 (file)
--- a/src/cpu/cpu_powerpc.c
+++ b/src/cpu/cpu_powerpc.c
@@ -304,12 +304,15 @@ ppcDecode(virCPUDefPtr cpu,
           const virCPUDataPtr data,
           const char **models,
           unsigned int nmodels,
-          const char *preferred ATTRIBUTE_UNUSED)
+          const char *preferred ATTRIBUTE_UNUSED,
+          unsigned int flags)
 {
     int ret = -1;
     struct ppc_map *map;
     const struct ppc_model *model;
 
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, -1);
+
     if (data == NULL || (map = ppcLoadMap()) == NULL)
         return -1;
 
@@ -377,7 +380,8 @@ static virCPUDefPtr
 ppcBaseline(virCPUDefPtr *cpus,
             unsigned int ncpus,
             const char **models,
-            unsigned int nmodels)
+            unsigned int nmodels,
+            unsigned int flags)
 {
     struct ppc_map *map = NULL;
     const struct ppc_model *model;
@@ -385,6 +389,8 @@ ppcBaseline(virCPUDefPtr *cpus,
     virCPUDefPtr cpu = NULL;
     size_t i;
 
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, NULL);
+
     if (!(map = ppcLoadMap()))
         goto error;
 

diff --git a/src/cpu/cpu_s390.c b/src/cpu/cpu_s390.c
index cbfae427950945da3ac291b99ae6012aec43208a..d997e06d9ab55474f9c7c8bc2550d05e6bd7bb28 100644 (file)
--- a/src/cpu/cpu_s390.c
+++ b/src/cpu/cpu_s390.c
@@ -48,8 +48,12 @@ s390Decode(virCPUDefPtr cpu ATTRIBUTE_UNUSED,
            const virCPUDataPtr data ATTRIBUTE_UNUSED,
            const char **models ATTRIBUTE_UNUSED,
            unsigned int nmodels ATTRIBUTE_UNUSED,
-           const char *preferred ATTRIBUTE_UNUSED)
+           const char *preferred ATTRIBUTE_UNUSED,
+           unsigned int flags)
 {
+
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, -1);
+
     return 0;
 }
 

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index a388f0f2b8b8590cbe83fb95aead70627bb6d8a0..41ce21fa7659ba9216251b8206f94b779f127807 100644 (file)
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -1319,13 +1319,42 @@ x86GuestData(virCPUDefPtr host,
     return x86Compute(host, guest, data, message);
 }
 
+static int
+x86AddFeatures(virCPUDefPtr cpu,
+               struct x86_map *map)
+{
+    const struct x86_model *candidate;
+    const struct x86_feature *feature = map->features;
+
+    candidate = map->models;
+    while (candidate != NULL) {
+        if (STREQ(cpu->model, candidate->name))
+            break;
+        candidate = candidate->next;
+    }
+    if (!candidate) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("%s not a known CPU model"), cpu->model);
+        return -1;
+    }
+    while (feature != NULL) {
+        if (x86DataIsSubset(candidate->data, feature->data) &&
+            virCPUDefAddFeature(cpu, feature->name,
+                                VIR_CPU_FEATURE_REQUIRE) < 0)
+            return -1;
+        feature = feature->next;
+    }
+    return 0;
+}
+
 
 static int
 x86Decode(virCPUDefPtr cpu,
           const struct cpuX86Data *data,
           const char **models,
           unsigned int nmodels,
-          const char *preferred)
+          const char *preferred,
+          unsigned int flags)
 {
     int ret = -1;
     struct x86_map *map;
@@ -1334,6 +1363,8 @@ x86Decode(virCPUDefPtr cpu,
     virCPUDefPtr cpuModel = NULL;
     size_t i;
 
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, -1);
+
     if (data == NULL || (map = x86LoadMap()) == NULL)
         return -1;
 
@@ -1406,6 +1437,9 @@ x86Decode(virCPUDefPtr cpu,
         goto out;
     }
 
+    if (flags & VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES &&
+        x86AddFeatures(cpuModel, map) < 0)
+        goto out;
     cpu->model = cpuModel->model;
     cpu->vendor = cpuModel->vendor;
     cpu->nfeatures = cpuModel->nfeatures;
@@ -1426,9 +1460,10 @@ x86DecodeCPUData(virCPUDefPtr cpu,
                  const virCPUDataPtr data,
                  const char **models,
                  unsigned int nmodels,
-                 const char *preferred)
+                 const char *preferred,
+                 unsigned int flags)
 {
-    return x86Decode(cpu, data->data.x86, models, nmodels, preferred);
+    return x86Decode(cpu, data->data.x86, models, nmodels, preferred, flags);
 }
 
 
@@ -1674,7 +1709,8 @@ static virCPUDefPtr
 x86Baseline(virCPUDefPtr *cpus,
             unsigned int ncpus,
             const char **models,
-            unsigned int nmodels)
+            unsigned int nmodels,
+            unsigned int flags)
 {
     struct x86_map *map = NULL;
     struct x86_model *base_model = NULL;
@@ -1755,7 +1791,7 @@ x86Baseline(virCPUDefPtr *cpus,
     if (vendor && x86DataAddCpuid(base_model->data, &vendor->cpuid) < 0)
         goto error;
 
-    if (x86Decode(cpu, base_model->data, models, nmodels, NULL) < 0)
+    if (x86Decode(cpu, base_model->data, models, nmodels, NULL, flags) < 0)
         goto error;
 
     if (!outputVendor)

diff --git a/src/libvirt.c b/src/libvirt.c
index 66e82485ae2d22f842cb0f5e967aec2a8561b886..07a3fd50224fc1dedabde7fc0a0ff7cc8a8e21d0 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -18524,11 +18524,16 @@ error:
  * @conn: virConnect connection
  * @xmlCPUs: array of XML descriptions of host CPUs
  * @ncpus: number of CPUs in xmlCPUs
- * @flags: extra flags; not used yet, so callers should always pass 0
+ * @flags: bitwise-OR of virConnectBaselineCPUFlags
  *
  * Computes the most feature-rich CPU which is compatible with all given
  * host CPUs.
  *
+ * If @flags includes VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES then libvirt
+ * will explicitly list all CPU features that are part of the host CPU,
+ * without this flag features that are part of the CPU model will not be
+ * listed.
+ *
  * Returns XML description of the computed CPU or NULL on error.
  */
 char *

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 2daafa8d16810e8191974488b87887ff18d1b68f..2ad236e0e187af04b8c0c08ae1c27ae1cbdcdba8 100644 (file)
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -11056,12 +11056,12 @@ qemuConnectBaselineCPU(virConnectPtr conn ATTRIBUTE_UNUSED,
 {
     char *cpu = NULL;
 
-    virCheckFlags(0, NULL);
+    virCheckFlags(VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, NULL);
 
     if (virConnectBaselineCPUEnsureACL(conn) < 0)
         goto cleanup;
 
-    cpu = cpuBaselineXML(xmlCPUs, ncpus, NULL, 0);
+    cpu = cpuBaselineXML(xmlCPUs, ncpus, NULL, 0, flags);
 
 cleanup:
     return cpu;

diff --git a/tests/cputest.c b/tests/cputest.c
index 2e5f0cdfb86053a24d3bc0129d9f00de57a906ff..959cb9fdc47cc1489d0b29daea221f67a954f92c 100644 (file)
--- a/tests/cputest.c
+++ b/tests/cputest.c
@@ -75,6 +75,7 @@ struct data {
     const char *modelsName;
     unsigned int nmodels;
     const char *preferred;
+    unsigned int flags;
     int result;
 };
 
@@ -330,7 +331,7 @@ cpuTestBaseline(const void *arg)
     if (!(cpus = cpuTestLoadMultiXML(data->arch, data->name, &ncpus)))
         goto cleanup;
 
-    baseline = cpuBaseline(cpus, ncpus, NULL, 0);
+    baseline = cpuBaseline(cpus, ncpus, NULL, 0, data->flags);
     if (data->result < 0) {
         virResetLastError();
         if (!baseline)
@@ -510,12 +511,12 @@ mymain(void)
     }
 
 #define DO_TEST(arch, api, name, host, cpu,                             \
-                models, nmodels, preferred, result)                     \
+                models, nmodels, preferred, flags, result)              \
     do {                                                                \
         static struct data data = {                                     \
             arch, api, host, cpu, models,                               \
             models == NULL ? NULL : #models,                            \
-            nmodels, preferred, result    \
+            nmodels, preferred, flags, result                           \
         };                                                              \
         if (cpuTestRun(name, &data) < 0)                                \
             ret = -1;                                                   \
@@ -524,31 +525,31 @@ mymain(void)
 #define DO_TEST_COMPARE(arch, host, cpu, result)                        \
     DO_TEST(arch, API_COMPARE,                                          \
             host "/" cpu " (" #result ")",                              \
-            host, cpu, NULL, 0, NULL, result)
+            host, cpu, NULL, 0, NULL, 0, result)
 
 #define DO_TEST_UPDATE(arch, host, cpu, result)                         \
     do {                                                                \
         DO_TEST(arch, API_UPDATE,                                       \
                 cpu " on " host,                                        \
-                host, cpu, NULL, 0, NULL, 0);                           \
+                host, cpu, NULL, 0, NULL, 0, 0);                        \
         DO_TEST_COMPARE(arch, host, host "+" cpu, result);              \
     } while (0)
 
-#define DO_TEST_BASELINE(arch, name, result)                            \
+#define DO_TEST_BASELINE(arch, name, flags, result)                     \
     DO_TEST(arch, API_BASELINE, name, NULL, "baseline-" name,           \
-            NULL, 0, NULL, result)
+            NULL, 0, NULL, flags, result)
 
 #define DO_TEST_HASFEATURE(arch, host, feature, result)                 \
     DO_TEST(arch, API_HAS_FEATURE,                                      \
             host "/" feature " (" #result ")",                          \
-            host, feature, NULL, 0, NULL, result)
+            host, feature, NULL, 0, NULL, 0, result)
 
 #define DO_TEST_GUESTDATA(arch, host, cpu, models, preferred, result)   \
     DO_TEST(arch, API_GUEST_DATA,                                       \
             host "/" cpu " (" #models ", pref=" #preferred ")",         \
             host, cpu, models,                                          \
             models == NULL ? 0 : sizeof(models) / sizeof(char *),       \
-            preferred, result)
+            preferred, 0, result)
 
     /* host to host comparison */
     DO_TEST_COMPARE("x86", "host", "host", VIR_CPU_COMPARE_IDENTICAL);
@@ -593,11 +594,12 @@ mymain(void)
     DO_TEST_UPDATE("x86", "host", "host-passthrough", VIR_CPU_COMPARE_IDENTICAL);
 
     /* computing baseline CPUs */
-    DO_TEST_BASELINE("x86", "incompatible-vendors", -1);
-    DO_TEST_BASELINE("x86", "no-vendor", 0);
-    DO_TEST_BASELINE("x86", "some-vendors", 0);
-    DO_TEST_BASELINE("x86", "1", 0);
-    DO_TEST_BASELINE("x86", "2", 0);
+    DO_TEST_BASELINE("x86", "incompatible-vendors", 0, -1);
+    DO_TEST_BASELINE("x86", "no-vendor", 0, 0);
+    DO_TEST_BASELINE("x86", "some-vendors", 0, 0);
+    DO_TEST_BASELINE("x86", "1", 0, 0);
+    DO_TEST_BASELINE("x86", "2", 0, 0);
+    DO_TEST_BASELINE("x86", "3", VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES, 0);
 
     /* CPU features */
     DO_TEST_HASFEATURE("x86", "host", "vmx", YES);

diff --git a/tests/cputestdata/x86-baseline-3-result.xml b/tests/cputestdata/x86-baseline-3-result.xml
new file mode 100644 (file)
index 0000000..d196112
--- /dev/null
+++ b/tests/cputestdata/x86-baseline-3-result.xml
@@ -0,0 +1,35 @@
+<cpu mode='custom' match='exact'>
+  <model fallback='allow'>Westmere</model>
+  <feature policy='require' name='lahf_lm'/>
+  <feature policy='require' name='lm'/>
+  <feature policy='require' name='nx'/>
+  <feature policy='require' name='syscall'/>
+  <feature policy='require' name='aes'/>
+  <feature policy='require' name='popcnt'/>
+  <feature policy='require' name='sse4.2'/>
+  <feature policy='require' name='sse4.1'/>
+  <feature policy='require' name='cx16'/>
+  <feature policy='require' name='ssse3'/>
+  <feature policy='require' name='pni'/>
+  <feature policy='require' name='sse2'/>
+  <feature policy='require' name='sse'/>
+  <feature policy='require' name='fxsr'/>
+  <feature policy='require' name='mmx'/>
+  <feature policy='require' name='clflush'/>
+  <feature policy='require' name='pse36'/>
+  <feature policy='require' name='pat'/>
+  <feature policy='require' name='cmov'/>
+  <feature policy='require' name='mca'/>
+  <feature policy='require' name='pge'/>
+  <feature policy='require' name='mtrr'/>
+  <feature policy='require' name='sep'/>
+  <feature policy='require' name='apic'/>
+  <feature policy='require' name='cx8'/>
+  <feature policy='require' name='mce'/>
+  <feature policy='require' name='pae'/>
+  <feature policy='require' name='msr'/>
+  <feature policy='require' name='tsc'/>
+  <feature policy='require' name='pse'/>
+  <feature policy='require' name='de'/>
+  <feature policy='require' name='fpu'/>
+</cpu>

diff --git a/tests/cputestdata/x86-baseline-3.xml b/tests/cputestdata/x86-baseline-3.xml
new file mode 100644 (file)
index 0000000..7654a1d
--- /dev/null
+++ b/tests/cputestdata/x86-baseline-3.xml
@@ -0,0 +1,7 @@
+<cpuTest>
+<cpu>
+  <arch>x86_64</arch>
+  <model>Westmere</model>
+  <topology sockets='1' cores='2' threads='1'/>
+</cpu>
+</cpuTest>

diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 18fcb3eec3fe4cfd6cbbb76ddb5606de3afee053..13e30451a835907e23e9c45f656d5039ca8cd01e 100644 (file)
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -6157,6 +6157,10 @@ static const vshCmdOptDef opts_cpu_baseline[] = {
      .flags = VSH_OFLAG_REQ,
      .help = N_("file containing XML CPU descriptions")
     },
+    {.name = "features",
+     .type = VSH_OT_BOOL,
+     .help = N_("Show features that are part of the CPU model type")
+    },
     {.name = NULL}
 };
 
@@ -6168,6 +6172,7 @@ cmdCPUBaseline(vshControl *ctl, const vshCmd *cmd)
     char *buffer;
     char *result = NULL;
     const char **list = NULL;
+    unsigned int flags = 0;
     int count = 0;
 
     xmlDocPtr xml = NULL;
@@ -6177,6 +6182,9 @@ cmdCPUBaseline(vshControl *ctl, const vshCmd *cmd)
     virBuffer buf = VIR_BUFFER_INITIALIZER;
     size_t i;
 
+    if (vshCommandOptBool(cmd, "features"))
+        flags |= VIR_CONNECT_BASELINE_CPU_EXPAND_FEATURES;
+
     if (vshCommandOptStringReq(ctl, cmd, "file", &from) < 0)
         return false;
 
@@ -6220,7 +6228,7 @@ cmdCPUBaseline(vshControl *ctl, const vshCmd *cmd)
         list[i] = vshStrdup(ctl, (const char *)xmlBufferContent(xml_buf));
     }
 
-    result = virConnectBaselineCPU(ctl->conn, list, count, 0);
+    result = virConnectBaselineCPU(ctl->conn, list, count, flags);
 
     if (result) {
         vshPrint(ctl, "%s", result);

diff --git a/tools/virsh.pod b/tools/virsh.pod
index 3ff6da14a810d9137db0d3b3c6f0d077e3a72363..0ae51780d5d64e041fec4042a225b464ee58f37e 100644 (file)
--- a/tools/virsh.pod
+++ b/tools/virsh.pod
@@ -485,13 +485,16 @@ cell and the total free memory on the machine.  Finally, with a
 numeric argument or with --cellno plus a cell number it will display
 the free memory for the specified cell only.
 
-=item B<cpu-baseline> I<FILE>
+=item B<cpu-baseline> I<FILE> [I<--features>]
 
 Compute baseline CPU which will be supported by all host CPUs given in <file>.
 The list of host CPUs is built by extracting all <cpu> elements from the
 <file>. Thus, the <file> can contain either a set of <cpu> elements separated
 by new lines or even a set of complete <capabilities> elements printed by
-B<capabilities> command.
+B<capabilities> command.  If I<--features> is specified then the
+resulting XML description will explicitly include all features that make
+up the CPU, without this option features that are part of the CPU model
+will not be listed in the XML description.
 
 =item B<cpu-compare> I<FILE>