libxl: introduce MSR data in libxl_cpuid_policy

Add a new array field to libxl_cpuid_policy in order to store the MSR
policies.

Adding the MSR data in the libxl_cpuid_policy_list type is done so
that existing users can seamlessly pass MSR features as part of the
CPUID data, without requiring the introduction of a separate
domain_build_info field, and a new set of handlers functions.

Note that support for parsing the old JSON format is kept, as that's
required in order to restore domains or received migrations from
previous tool versions.  Differentiation between the old and the new
formats is done based on whether the contents of the 'cpuid' field is
an array or a map JSON object.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Anthony PERARD <anthony.perard@citrix.com>
(cherry picked from commit 5b80cecb747b2176b9e85f6e7aa7be83416d77e1)

diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
index 48802b9f7c8cc49e7a70ff0f16ba44a84676d6e5..f003cea6ebd835960c706b5602d93acc63ff1e90 100644 (file)
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -16,7 +16,7 @@
 
 int libxl__cpuid_policy_is_empty(libxl_cpuid_policy_list *pl)
 {
-    return !libxl_cpuid_policy_list_length(pl);
+    return !*pl || (!libxl_cpuid_policy_list_length(pl) && !(*pl)->msr);
 }
 
 void libxl_cpuid_dispose(libxl_cpuid_policy_list *pl)
@@ -40,6 +40,8 @@ void libxl_cpuid_dispose(libxl_cpuid_policy_list *pl)
         free(policy->cpuid);
     }
 
+    free(policy->msr);
+
     free(policy);
     *pl = NULL;
     return;
@@ -503,7 +505,8 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
 
     r = xc_cpuid_apply_policy(ctx->xch, domid, restore, NULL, 0,
                               pae, itsc, nested_virt,
-                              info->cpuid ? info->cpuid->cpuid : NULL, NULL);
+                              info->cpuid ? info->cpuid->cpuid : NULL,
+                              info->cpuid ? info->cpuid->msr : NULL);
     if (r)
         LOGEVD(ERROR, -r, domid, "Failed to apply CPUID policy");
 
@@ -515,16 +518,22 @@ static const char *input_names[2] = { "leaf", "subleaf" };
 static const char *policy_names[4] = { "eax", "ebx", "ecx", "edx" };
 /*
  * Aiming for:
- * [
- *     { 'leaf':    'val-eax',
- *       'subleaf': 'val-ecx',
- *       'eax':     'filter',
- *       'ebx':     'filter',
- *       'ecx':     'filter',
- *       'edx':     'filter' },
- *     { 'leaf':    'val-eax', ..., 'eax': 'filter', ... },
- *     ... etc ...
- * ]
+ * {   'cpuid': [
+ *              { 'leaf':    'val-eax',
+ *                'subleaf': 'val-ecx',
+ *                'eax':     'filter',
+ *                'ebx':     'filter',
+ *                'ecx':     'filter',
+ *                'edx':     'filter' },
+ *              { 'leaf':    'val-eax', ..., 'eax': 'filter', ... },
+ *              ... etc ...
+ *     ],
+ *     'msr': [
+ *            { 'index': 'val-index',
+ *              'policy': 'filter', },
+ *              ... etc ...
+ *     ],
+ * }
  */
 
 yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
@@ -532,9 +541,16 @@ yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
 {
     libxl_cpuid_policy_list policy = *pl;
     struct xc_xend_cpuid *cpuid;
+    const struct xc_msr *msr;
     yajl_gen_status s;
     int i, j;
 
+    s = yajl_gen_map_open(hand);
+    if (s != yajl_gen_status_ok) goto out;
+
+    s = libxl__yajl_gen_asciiz(hand, "cpuid");
+    if (s != yajl_gen_status_ok) goto out;
+
     s = yajl_gen_array_open(hand);
     if (s != yajl_gen_status_ok) goto out;
 
@@ -569,6 +585,39 @@ yajl_gen_status libxl_cpuid_policy_list_gen_json(yajl_gen hand,
 
 empty:
     s = yajl_gen_array_close(hand);
+    if (s != yajl_gen_status_ok) goto out;
+
+    s = libxl__yajl_gen_asciiz(hand, "msr");
+    if (s != yajl_gen_status_ok) goto out;
+
+    s = yajl_gen_array_open(hand);
+    if (s != yajl_gen_status_ok) goto out;
+
+    if (!policy || !policy->msr) goto done;
+    msr = policy->msr;
+
+    for (i = 0; msr[i].index != XC_MSR_INPUT_UNUSED; i++) {
+        s = yajl_gen_map_open(hand);
+        if (s != yajl_gen_status_ok) goto out;
+
+        s = libxl__yajl_gen_asciiz(hand, "index");
+        if (s != yajl_gen_status_ok) goto out;
+        s = yajl_gen_integer(hand, msr[i].index);
+        if (s != yajl_gen_status_ok) goto out;
+        s = libxl__yajl_gen_asciiz(hand, "policy");
+        if (s != yajl_gen_status_ok) goto out;
+        s = yajl_gen_string(hand,
+                            (const unsigned char *)msr[i].policy, 64);
+        if (s != yajl_gen_status_ok) goto out;
+
+        s = yajl_gen_map_close(hand);
+        if (s != yajl_gen_status_ok) goto out;
+    }
+
+done:
+    s = yajl_gen_array_close(hand);
+    if (s != yajl_gen_status_ok) goto out;
+    s = yajl_gen_map_close(hand);
 out:
     return s;
 }
@@ -579,17 +628,40 @@ int libxl__cpuid_policy_list_parse_json(libxl__gc *gc,
 {
     int i, size;
     struct xc_xend_cpuid *l;
+    struct xc_msr *msr;
+    const libxl__json_object *co;
     flexarray_t *array;
+    bool cpuid_only = false;
+
+    /*
+     * Old JSON field was an array with just the CPUID data.  With the addition
+     * of MSRs the object is now a map with two array fields.
+     *
+     * Use the object format to detect whether the passed data contains just
+     * CPUID leafs and thus is an array, or does also contain MSRs and is a
+     * map.
+     */
+    if (libxl__json_object_is_array(o)) {
+        co = o;
+        cpuid_only = true;
+        goto parse_cpuid;
+    }
 
-    if (!libxl__json_object_is_array(o))
+    if (!libxl__json_object_is_map(o))
         return ERROR_FAIL;
 
-    array = libxl__json_object_get_array(o);
+    co = libxl__json_map_get("cpuid", o, JSON_ARRAY);
+    if (!libxl__json_object_is_array(co))
+        return ERROR_FAIL;
+
+parse_cpuid:
+    *p = libxl__calloc(NOGC, 1, sizeof(**p));
+
+    array = libxl__json_object_get_array(co);
     if (!array->count)
-        return 0;
+        goto cpuid_empty;
 
     size = array->count;
-    *p = libxl__calloc(NOGC, 1, sizeof(**p));
     /* need one extra slot as sentinel */
     l = (*p)->cpuid = libxl__calloc(NOGC, size + 1,
                                     sizeof(struct xc_xend_cpuid));
@@ -628,6 +700,42 @@ int libxl__cpuid_policy_list_parse_json(libxl__gc *gc,
                     libxl__strdup(NOGC, libxl__json_object_get_string(r));
         }
     }
+    if (cpuid_only)
+        return 0;
+
+cpuid_empty:
+    co = libxl__json_map_get("msr", o, JSON_ARRAY);
+    if (!libxl__json_object_is_array(co))
+        return ERROR_FAIL;
+
+    array = libxl__json_object_get_array(co);
+    if (!array->count)
+        return 0;
+    size = array->count;
+    /* need one extra slot as sentinel */
+    msr = (*p)->msr = libxl__calloc(NOGC, size + 1, sizeof(struct xc_msr));
+
+    msr[size].index = XC_MSR_INPUT_UNUSED;
+
+    for (i = 0; i < size; i++) {
+        const libxl__json_object *t, *r;
+
+        if (flexarray_get(array, i, (void**)&t) != 0)
+            return ERROR_FAIL;
+
+        if (!libxl__json_object_is_map(t))
+            return ERROR_FAIL;
+
+        r = libxl__json_map_get("index", t, JSON_INTEGER);
+        if (!r) return ERROR_FAIL;
+        msr[i].index = libxl__json_object_get_integer(r);
+        r = libxl__json_map_get("policy", t, JSON_STRING);
+        if (!r) return ERROR_FAIL;
+        if (strlen(libxl__json_object_get_string(r)) !=
+            ARRAY_SIZE(msr[i].policy) - 1)
+            return ERROR_FAIL;
+        strcpy(msr[i].policy, libxl__json_object_get_string(r));
+    }
 
     return 0;
 }
@@ -664,6 +772,10 @@ void libxl_cpuid_policy_list_copy(libxl_ctx *ctx,
     }
 
     *pdst = libxl__calloc(NOGC, 1, sizeof(**pdst));
+
+    if (!(*psrc)->cpuid)
+        goto copy_msr;
+
     dst = &(*pdst)->cpuid;
     src = &(*psrc)->cpuid;
     len = libxl_cpuid_policy_list_length(psrc);
@@ -683,6 +795,22 @@ void libxl_cpuid_policy_list_copy(libxl_ctx *ctx,
                 (*dst)[i].policy[j] = NULL;
     }
 
+copy_msr:
+    if ((*psrc)->msr) {
+        const struct xc_msr *msr = (*psrc)->msr;
+
+        for (i = 0; msr[i].index != XC_MSR_INPUT_UNUSED; i++)
+            ;
+        len = i;
+        (*pdst)->msr = libxl__calloc(NOGC, len + 1, sizeof(struct xc_msr));
+        (*pdst)->msr[len].index = XC_MSR_INPUT_UNUSED;
+
+        for (i = 0; i < len; i++) {
+            (*pdst)->msr[i].index = msr[i].index;
+            strcpy((*pdst)->msr[i].policy, msr[i].policy);
+        }
+    }
+
 out:
     GC_FREE;
 }

diff --git a/tools/libs/light/libxl_internal.h b/tools/libs/light/libxl_internal.h
index 8c67a0eeb3cdf2757dac05fa9f4bb66fea30b4f1..cc27c72ecf305d462004f20e388ac0d399bb6044 100644 (file)
--- a/tools/libs/light/libxl_internal.h
+++ b/tools/libs/light/libxl_internal.h
@@ -4861,6 +4861,7 @@ int libxl__setresuid(uid_t ruid, uid_t euid, uid_t suid);
 
 struct libxl__cpu_policy {
     struct xc_xend_cpuid *cpuid;
+    struct xc_msr *msr;
 };
 
 #endif

diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 2a42da2f7d7808b6fc4cb8e6ae7839590e29649f..ef59b205f30d4aba33f570b42ed51a6750bb4890 100644 (file)
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -19,7 +19,7 @@ libxl_mac = Builtin("mac", json_parse_type="JSON_STRING", passby=PASS_BY_REFEREN
 libxl_bitmap = Builtin("bitmap", json_parse_type="JSON_ARRAY", dispose_fn="libxl_bitmap_dispose", passby=PASS_BY_REFERENCE,
                        check_default_fn="libxl_bitmap_is_empty", copy_fn="libxl_bitmap_copy_alloc")
 libxl_cpuid_policy_list = Builtin("cpuid_policy_list", dispose_fn="libxl_cpuid_dispose", passby=PASS_BY_REFERENCE,
-                                  json_parse_type="JSON_ARRAY", check_default_fn="libxl__cpuid_policy_is_empty",
+                                  json_parse_type="JSON_ANY", check_default_fn="libxl__cpuid_policy_is_empty",
                                   copy_fn="libxl_cpuid_policy_list_copy")
 
 libxl_string_list = Builtin("string_list", dispose_fn="libxl_string_list_dispose", passby=PASS_BY_REFERENCE,