[libvirt] [PATCH v2 2/4] libxl: add support for CPUID features policy

[Marek Marczykowski-Górecki]

Convert CPU features policy into libxl cpuid policy settings. Use new
("libxl") syntax, which allow to enable/disable specific bits, using
host CPU as a base. For this reason, accept only "host-passthrough"
mode.
Libxl do not have distinction between "force" and "required" policy
(there is only "force") and also between "forbid" and "disable" (there
is only "disable"). So, merge them appropriately. If anything, "require"
and "forbid" should be enforced outside of specific driver.

Signed-off-by: Marek Marczykowski-Górecki <marmarek at invisiblethingslab.com>
---
Changes since v1:
 - use new ("libxl") syntax to set only bits explicitly mentioned in
 domain XML
---
 src/libxl/libxl_conf.c | 77 ++++++++++++++++++++++++++++++++++++++++---
 src/libxl/libxl_conf.h |  1 +-
 2 files changed, 74 insertions(+), 4 deletions(-)

diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c
index a0a53c2..0cf51a8 100644
--- a/src/libxl/libxl_conf.c
+++ b/src/libxl/libxl_conf.c
@@ -291,6 +291,44 @@ libxlMakeChrdevStr(virDomainChrDefPtr def, char **buf)
     return 0;
 }
 
+static const char *libxlTranslateCPUFeature(const char *virCPUFeatureName)
+{
+    /* libxl use different names for some CPUID bits */
+    if (STREQ(virCPUFeatureName, "cx16"))
+        return "cmpxchg16";
+    if (STREQ(virCPUFeatureName, "cid"))
+        return "cntxid";
+    if (STREQ(virCPUFeatureName, "ds_cpl"))
+        return "dscpl";
+    if (STREQ(virCPUFeatureName, "pclmuldq"))
+        return "pclmulqdq";
+    if (STREQ(virCPUFeatureName, "pni"))
+        return "sse3";
+    if (STREQ(virCPUFeatureName, "ht"))
+        return "htt";
+    if (STREQ(virCPUFeatureName, "pn"))
+        return "psn";
+    if (STREQ(virCPUFeatureName, "clflush"))
+        return "clfsh";
+    if (STREQ(virCPUFeatureName, "sep"))
+        return "sysenter";
+    if (STREQ(virCPUFeatureName, "cx8"))
+        return "cmpxchg8";
+    if (STREQ(virCPUFeatureName, "nodeid_msr"))
+        return "nodeid";
+    if (STREQ(virCPUFeatureName, "cr8legacy"))
+        return "altmovcr8";
+    if (STREQ(virCPUFeatureName, "lahf_lm"))
+        return "lahfsahf";
+    if (STREQ(virCPUFeatureName, "cmp_legacy"))
+        return "cmplegacy";
+    if (STREQ(virCPUFeatureName, "fxsr_opt"))
+        return "ffxsr";
+    if (STREQ(virCPUFeatureName, "pdpe1gb"))
+        return "page1gb";
+    return virCPUFeatureName;
+}
+
 static int
 libxlMakeDomBuildInfo(virDomainDefPtr def,
                       libxl_ctx *ctx,
@@ -376,10 +414,18 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
                           def->features[VIR_DOMAIN_FEATURE_ACPI] ==
                           VIR_TRISTATE_SWITCH_ON);
 
-        if (caps &&
-            def->cpu && def->cpu->mode == (VIR_CPU_MODE_HOST_PASSTHROUGH)) {
+        if (caps && def->cpu) {
             bool hasHwVirt = false;
             bool svm = false, vmx = false;
+            char xlCPU[32];
+
+            if (def->cpu->mode != (VIR_CPU_MODE_HOST_PASSTHROUGH)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("unsupported cpu mode '%s'"),
+                               virCPUModeTypeToString(def->cpu->mode));
+                return -1;
+            }
+
 
             if (ARCH_IS_X86(def->os.arch)) {
                 vmx = virCPUCheckFeature(caps->host.arch, caps->host.cpu, "vmx");
@@ -394,20 +440,43 @@ libxlMakeDomBuildInfo(virDomainDefPtr def,
 
                         case VIR_CPU_FEATURE_DISABLE:
                         case VIR_CPU_FEATURE_FORBID:
+                            snprintf(xlCPU,
+                                    sizeof(xlCPU),
+                                    "%s=0",
+                                    libxlTranslateCPUFeature(
+                                        def->cpu->features[i].name));
+                            if (libxl_cpuid_parse_config(&b_info->cpuid, xlCPU)) {
+                                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                                        _("unsupported cpu feature '%s'"),
+                                        def->cpu->features[i].name);
+                                return -1;
+                            }
                             if ((vmx && STREQ(def->cpu->features[i].name, "vmx")) ||
-                                (svm && STREQ(def->cpu->features[i].name, "svm")))
+                                    (svm && STREQ(def->cpu->features[i].name, "svm")))
                                 hasHwVirt = false;
                             break;
 
                         case VIR_CPU_FEATURE_FORCE:
                         case VIR_CPU_FEATURE_REQUIRE:
+                            snprintf(xlCPU,
+                                    sizeof(xlCPU),
+                                    "%s=1",
+                                    libxlTranslateCPUFeature(
+                                        def->cpu->features[i].name));
+                            if (libxl_cpuid_parse_config(&b_info->cpuid, xlCPU)) {
+                                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                                        _("unsupported cpu feature '%s'"),
+                                        def->cpu->features[i].name);
+                                return -1;
+                            }
+                            break;
                         case VIR_CPU_FEATURE_OPTIONAL:
                         case VIR_CPU_FEATURE_LAST:
                             break;
                     }
                 }
+                libxl_defbool_set(&b_info->u.hvm.nested_hvm, hasHwVirt);
             }
-            libxl_defbool_set(&b_info->u.hvm.nested_hvm, hasHwVirt);
         }
 
         if (def->nsounds > 0) {
diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
index 264df11..8d89ccd 100644
--- a/src/libxl/libxl_conf.h
+++ b/src/libxl/libxl_conf.h
@@ -60,6 +60,7 @@
 # define LIBXL_DUMP_DIR LIBXL_LIB_DIR "/dump"
 # define LIBXL_CHANNEL_DIR LIBXL_LIB_DIR "/channel/target"
 # define LIBXL_BOOTLOADER_PATH "pygrub"
+# define LIBXL_DEFAULT_CPUID_REG_CONFIG "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 
 
 typedef struct _libxlDriverPrivate libxlDriverPrivate;
-- 
git-series 0.9.1