libs/guest: allow updating a cpu policy CPUID data

Introduce a helper to update the CPUID policy using an array of
xen_cpuid_leaf_t entries. Note the leaves present in the input
xen_cpuid_leaf_t array will replace any existing leaves on the policy.

No user of the interface introduced on this patch.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 27cec1b93ffb6be05c103261ac49f2e9d171bd91..543bd2a4c246884f255c47329475df3b0d04cfda 100644 (file)
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -2608,6 +2608,9 @@ int xc_cpu_policy_set_domain(xc_interface *xch, uint32_t domid,
 int xc_cpu_policy_serialise(xc_interface *xch, const xc_cpu_policy_t policy,
                             xen_cpuid_leaf_t *leaves, uint32_t *nr_leaves,
                             xen_msr_entry_t *msrs, uint32_t *nr_msrs);
+int xc_cpu_policy_update_cpuid(xc_interface *xch, xc_cpu_policy_t policy,
+                               const xen_cpuid_leaf_t *leaves,
+                               uint32_t nr);
 
 int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps);
 int xc_get_cpu_featureset(xc_interface *xch, uint32_t index,

diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index 0c9b3a960f000627aaeec6d96b3471d8ab276076..713649edde09272a4e03eeee074e9677f388e943 100644 (file)
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -822,3 +822,23 @@ int xc_cpu_policy_serialise(xc_interface *xch, const xc_cpu_policy_t p,
     errno = 0;
     return 0;
 }
+
+int xc_cpu_policy_update_cpuid(xc_interface *xch, xc_cpu_policy_t policy,
+                               const xen_cpuid_leaf_t *leaves,
+                               uint32_t nr)
+{
+    unsigned int err_leaf = -1, err_subleaf = -1;
+    int rc = x86_cpuid_copy_from_buffer(&policy->cpuid, leaves, nr,
+                                        &err_leaf, &err_subleaf);
+
+    if ( rc )
+    {
+        if ( err_leaf != -1 )
+            ERROR("Failed to update CPUID (err leaf %#x, subleaf %#x) (%d = %s)",
+                  err_leaf, err_subleaf, -rc, strerror(-rc));
+        errno = -rc;
+        rc = -1;
+    }
+
+    return rc;
+}