[PATCH v4 10/10] libs/guest: (re)move xc_cpu_policy_apply_cpuid

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

Move the logic from xc_cpu_policy_apply_cpuid into libxl, now that the
xc_cpu_policy_* helpers allow modifying a cpu policy. By moving such
parsing into libxl directly we can get rid of xc_xend_cpuid, as libxl
will now implement it's own private type for storing CPUID
information, which currently matches xc_xend_cpuid.

Note the function logic is moved as-is, but requires adapting to the
libxl coding style.

No functional change intended.

Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Reviewed-by: Anthony PERARD <anthony.perard@xxxxxxxxxx>
---
Changes since v2:
 - Use LOG*D.
 - Pass a gc to apply_policy.
 - Use 'r' for libxc return values.
---
 tools/include/libxl.h             |   6 +-
 tools/include/xenctrl.h           |  26 ------
 tools/include/xenguest.h          |   4 -
 tools/libs/guest/xg_cpuid_x86.c   | 125 --------------------------
 tools/libs/light/libxl_cpuid.c    | 142 ++++++++++++++++++++++++++++--
 tools/libs/light/libxl_internal.h |  26 ++++++
 6 files changed, 165 insertions(+), 164 deletions(-)

diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index ae7fe27c1f2..150b7ba85ac 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -1375,10 +1375,10 @@ void libxl_bitmap_init(libxl_bitmap *map);
 void libxl_bitmap_dispose(libxl_bitmap *map);
 
 /*
- * libxl_cpuid_policy is opaque in the libxl ABI.  Users of both libxl and
- * libxc may not make assumptions about xc_xend_cpuid.
+ * libxl_cpuid_policy is opaque in the libxl ABI. Users of libxl may not make
+ * assumptions about libxl__cpuid_policy.
  */
-typedef struct xc_xend_cpuid libxl_cpuid_policy;
+typedef struct libxl__cpuid_policy libxl_cpuid_policy;
 typedef libxl_cpuid_policy * libxl_cpuid_policy_list;
 void libxl_cpuid_dispose(libxl_cpuid_policy_list *cpuid_list);
 int libxl_cpuid_policy_list_length(const libxl_cpuid_policy_list *l);
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 17fa3734800..30c2a5f5284 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -1864,32 +1864,6 @@ int xc_domain_debug_control(xc_interface *xch,
 
 #if defined(__i386__) || defined(__x86_64__)
 
-/*
- * CPUID policy data, expressed in the legacy XEND format.
- *
- * Policy is an array of strings, 32 chars long:
- *   policy[0] = eax
- *   policy[1] = ebx
- *   policy[2] = ecx
- *   policy[3] = edx
- *
- * The format of the string is the following:
- *   '1' -> force to 1
- *   '0' -> force to 0
- *   'x' -> we don't care (use default)
- *   'k' -> pass through host value
- *   's' -> legacy alias for 'k'
- */
-struct xc_xend_cpuid {
-    union {
-        struct {
-            uint32_t leaf, subleaf;
-        };
-        uint32_t input[2];
-    };
-    char *policy[4];
-};
-
 int xc_mca_op(xc_interface *xch, struct xen_mc *mc);
 int xc_mca_op_inject_v2(xc_interface *xch, unsigned int flags,
                         xc_cpumap_t cpumap, unsigned int nr_cpus);
diff --git a/tools/include/xenguest.h b/tools/include/xenguest.h
index 134c00f29a0..414baa30171 100644
--- a/tools/include/xenguest.h
+++ b/tools/include/xenguest.h
@@ -762,10 +762,6 @@ int xc_cpu_policy_make_compat_4_12(xc_interface *xch, 
xc_cpu_policy_t *policy,
 int xc_cpu_policy_legacy_topology(xc_interface *xch, xc_cpu_policy_t *policy,
                                   bool hvm);
 
-/* Apply an xc_xend_cpuid object to the policy. */
-int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
-                              const struct xc_xend_cpuid *cpuid, bool hvm);
-
 /* Apply a featureset to the policy. */
 int xc_cpu_policy_apply_featureset(xc_interface *xch, xc_cpu_policy_t *policy,
                                    const uint32_t *featureset,
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 8c62c3ac360..e0fff98fe77 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -263,131 +263,6 @@ int xc_set_domain_cpu_policy(xc_interface *xch, uint32_t 
domid,
     return ret;
 }
 
-int xc_cpu_policy_apply_cpuid(xc_interface *xch, xc_cpu_policy_t *policy,
-                              const struct xc_xend_cpuid *cpuid, bool hvm)
-{
-    int rc;
-    xc_cpu_policy_t *host = NULL, *def = NULL;
-
-    host = xc_cpu_policy_init();
-    def = xc_cpu_policy_init();
-    if ( !host || !def )
-    {
-        PERROR("Failed to init policies");
-        rc = -ENOMEM;
-        goto out;
-    }
-
-    /* Get the domain type's default policy. */
-    rc = xc_cpu_policy_get_system(xch, hvm ? XEN_SYSCTL_cpu_policy_hvm_default
-                                           : XEN_SYSCTL_cpu_policy_pv_default,
-                                  def);
-    if ( rc )
-    {
-        PERROR("Failed to obtain %s def policy", hvm ? "hvm" : "pv");
-        goto out;
-    }
-
-    /* Get the host policy. */
-    rc = xc_cpu_policy_get_system(xch, XEN_SYSCTL_cpu_policy_host, host);
-    if ( rc )
-    {
-        PERROR("Failed to obtain host policy");
-        goto out;
-    }
-
-    rc = -EINVAL;
-    for ( ; cpuid->leaf != XEN_CPUID_INPUT_UNUSED; ++cpuid )
-    {
-        xen_cpuid_leaf_t cur_leaf;
-        xen_cpuid_leaf_t def_leaf;
-        xen_cpuid_leaf_t host_leaf;
-
-        rc = xc_cpu_policy_get_cpuid(xch, policy, cpuid->leaf, cpuid->subleaf,
-                                     &cur_leaf);
-        if ( rc )
-        {
-            ERROR("Failed to get current policy leaf %#x subleaf %#x",
-                  cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-        rc = xc_cpu_policy_get_cpuid(xch, def, cpuid->leaf, cpuid->subleaf,
-                                     &def_leaf);
-        if ( rc )
-        {
-            ERROR("Failed to get def policy leaf %#x subleaf %#x",
-                  cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-        rc = xc_cpu_policy_get_cpuid(xch, host, cpuid->leaf, cpuid->subleaf,
-                                     &host_leaf);
-        if ( rc )
-        {
-            ERROR("Failed to get host policy leaf %#x subleaf %#x",
-                  cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-
-        for ( unsigned int i = 0; i < ARRAY_SIZE(cpuid->policy); i++ )
-        {
-            uint32_t *cur_reg = &cur_leaf.a + i;
-            const uint32_t *def_reg = &def_leaf.a + i;
-            const uint32_t *host_reg = &host_leaf.a + i;
-
-            if ( cpuid->policy[i] == NULL )
-                continue;
-
-            for ( unsigned int j = 0; j < 32; j++ )
-            {
-                bool val;
-
-                switch ( cpuid->policy[i][j] )
-                {
-                case '1':
-                    val = true;
-                    break;
-
-                case '0':
-                    val = false;
-                    break;
-
-                case 'x':
-                    val = test_bit(31 - j, def_reg);
-                    break;
-
-                case 'k':
-                case 's':
-                    val = test_bit(31 - j, host_reg);
-                    break;
-
-                default:
-                    ERROR("Bad character '%c' in policy[%d] string '%s'",
-                          cpuid->policy[i][j], i, cpuid->policy[i]);
-                    goto out;
-                }
-
-                clear_bit(31 - j, cur_reg);
-                if ( val )
-                    set_bit(31 - j, cur_reg);
-            }
-        }
-
-        rc = xc_cpu_policy_update_cpuid(xch, policy, &cur_leaf, 1);
-        if ( rc )
-        {
-            PERROR("Failed to set policy leaf %#x subleaf %#x",
-                   cpuid->leaf, cpuid->subleaf);
-            goto out;
-        }
-    }
-
- out:
-    xc_cpu_policy_destroy(def);
-    xc_cpu_policy_destroy(host);
-
-    return rc;
-}
-
 xc_cpu_policy_t *xc_cpu_policy_init(void)
 {
     return calloc(1, sizeof(struct xc_cpu_policy));
diff --git a/tools/libs/light/libxl_cpuid.c b/tools/libs/light/libxl_cpuid.c
index 6d17e89191f..6c11b7a7c1f 100644
--- a/tools/libs/light/libxl_cpuid.c
+++ b/tools/libs/light/libxl_cpuid.c
@@ -298,7 +298,7 @@ int libxl_cpuid_parse_config(libxl_cpuid_policy_list 
*cpuid, const char* str)
     char *sep, *val, *endptr;
     int i;
     const struct cpuid_flags *flag;
-    struct xc_xend_cpuid *entry;
+    struct libxl__cpuid_policy *entry;
     unsigned long num;
     char flags[33], *resstr;
 
@@ -376,7 +376,7 @@ int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list 
*cpuid,
     char *endptr;
     unsigned long value;
     uint32_t leaf, subleaf = XEN_CPUID_INPUT_UNUSED;
-    struct xc_xend_cpuid *entry;
+    struct libxl__cpuid_policy *entry;
 
     /* parse the leaf number */
     value = strtoul(str, &endptr, 0);
@@ -426,6 +426,137 @@ int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list 
*cpuid,
     return 0;
 }
 
+static int apply_cpuid(libxl__gc *gc, xc_cpu_policy_t *policy,
+                       libxl_cpuid_policy_list cpuid, bool hvm, domid_t domid)
+{
+    int r, rc = 0;
+    xc_cpu_policy_t *host = NULL, *def = NULL;
+
+    host = xc_cpu_policy_init();
+    def = xc_cpu_policy_init();
+    if (!host || !def) {
+        LOGD(ERROR, domid, "Failed to init policies");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    /* Get the domain type's default policy. */
+    r = xc_cpu_policy_get_system(CTX->xch,
+                                 hvm ? XEN_SYSCTL_cpu_policy_hvm_default
+                                     : XEN_SYSCTL_cpu_policy_pv_default,
+                                 def);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to obtain %s def policy",
+              hvm ? "hvm" : "pv");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    /* Get the host policy. */
+    r = xc_cpu_policy_get_system(CTX->xch, XEN_SYSCTL_cpu_policy_host, host);
+    if (r) {
+        LOGED(ERROR, domid, "Failed to obtain host policy");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    for (; cpuid->leaf != XEN_CPUID_INPUT_UNUSED; ++cpuid) {
+        xen_cpuid_leaf_t cur_leaf;
+        xen_cpuid_leaf_t def_leaf;
+        xen_cpuid_leaf_t host_leaf;
+
+        r = xc_cpu_policy_get_cpuid(CTX->xch, policy, cpuid->leaf,
+                                    cpuid->subleaf, &cur_leaf);
+        if (r) {
+            LOGED(ERROR, domid,
+                  "Failed to get current policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            r = ERROR_FAIL;
+            goto out;
+        }
+        r = xc_cpu_policy_get_cpuid(CTX->xch, def, cpuid->leaf, cpuid->subleaf,
+                                    &def_leaf);
+        if (r) {
+            LOGED(ERROR, domid,
+                  "Failed to get def policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            rc = ERROR_FAIL;
+            goto out;
+        }
+        r = xc_cpu_policy_get_cpuid(CTX->xch, host, cpuid->leaf,
+                                    cpuid->subleaf, &host_leaf);
+        if (r) {
+            LOGED(ERROR, domid,
+                  "Failed to get host policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            rc = ERROR_FAIL;
+            goto out;
+        }
+
+        for (unsigned int i = 0; i < ARRAY_SIZE(cpuid->policy); i++) {
+            uint32_t *cur_reg = &cur_leaf.a + i;
+            const uint32_t *def_reg = &def_leaf.a + i;
+            const uint32_t *host_reg = &host_leaf.a + i;
+
+            if (cpuid->policy[i] == NULL)
+                continue;
+
+#define test_bit(i, r) !!(*(r) & (1u << (i)))
+#define set_bit(i, r) (*(r) |= (1u << (i)))
+#define clear_bit(i, r)  (*(r) &= ~(1u << (i)))
+            for (unsigned int j = 0; j < 32; j++) {
+                bool val;
+
+                switch (cpuid->policy[i][j]) {
+                case '1':
+                    val = true;
+                    break;
+
+                case '0':
+                    val = false;
+                    break;
+
+                case 'x':
+                    val = test_bit(31 - j, def_reg);
+                    break;
+
+                case 'k':
+                case 's':
+                    val = test_bit(31 - j, host_reg);
+                    break;
+
+                default:
+                    LOGD(ERROR, domid,
+                         "Bad character '%c' in policy[%d] string '%s'",
+                         cpuid->policy[i][j], i, cpuid->policy[i]);
+                    rc = ERROR_FAIL;
+                    goto out;
+                }
+
+                clear_bit(31 - j, cur_reg);
+                if (val)
+                    set_bit(31 - j, cur_reg);
+            }
+#undef clear_bit
+#undef set_bit
+#undef test_bit
+        }
+
+        r = xc_cpu_policy_update_cpuid(CTX->xch, policy, &cur_leaf, 1);
+        if (r) {
+            LOGED(ERROR, domid, "Failed to set policy leaf %#x subleaf %#x",
+                  cpuid->leaf, cpuid->subleaf);
+            rc = ERROR_FAIL;
+            goto out;
+        }
+    }
+
+ out:
+    xc_cpu_policy_destroy(def);
+    xc_cpu_policy_destroy(host);
+    return rc;
+}
+
 int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
                         libxl_domain_build_info *info)
 {
@@ -541,10 +672,9 @@ int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, 
bool restore,
     }
 
     /* Apply the bits from info->cpuid if any. */
-    r = xc_cpu_policy_apply_cpuid(ctx->xch, policy, info->cpuid, hvm);
-    if (r) {
-        LOGEVD(ERROR, domid, -r, "Failed to apply CPUID changes");
-        rc = ERROR_FAIL;
+    rc = apply_cpuid(gc, policy, info->cpuid, hvm, domid);
+    if (rc) {
+        LOGD(ERROR, domid, "Failed to apply CPUID changes");
         goto out;
     }
 
diff --git a/tools/libs/light/libxl_internal.h 
b/tools/libs/light/libxl_internal.h
index 44a2f3c8fe3..f271a729fa7 100644
--- a/tools/libs/light/libxl_internal.h
+++ b/tools/libs/light/libxl_internal.h
@@ -2052,6 +2052,32 @@ typedef yajl_gen_status 
(*libxl__gen_json_callback)(yajl_gen hand, void *);
 _hidden char *libxl__object_to_json(libxl_ctx *ctx, const char *type,
                                     libxl__gen_json_callback gen, void *p);
 
+/*
+ * CPUID policy data, expressed in the internal libxl format.
+ *
+ * Policy is an array of strings, 32 chars long:
+ *   policy[0] = eax
+ *   policy[1] = ebx
+ *   policy[2] = ecx
+ *   policy[3] = edx
+ *
+ * The format of the string is the following:
+ *   '1' -> force to 1
+ *   '0' -> force to 0
+ *   'x' -> we don't care (use default)
+ *   'k' -> pass through host value
+ *   's' -> legacy alias for 'k'
+ */
+struct libxl__cpuid_policy {
+    union {
+        struct {
+            uint32_t leaf, subleaf;
+        };
+        uint32_t input[2];
+    };
+    char *policy[4];
+};
+
 _hidden int libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool retore,
                                 libxl_domain_build_info *info);
 
-- 
2.31.1