Such helper is based on the existing functions to fetch a CPUID and
MSR policies, but uses the xc_cpu_policy_t type to return the data to
the caller.
Note some helper functions are introduced, those are split from
xc_cpu_policy_get_system because they will be used by other functions
also.
No user of the interface introduced on the patch.
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
---
tools/include/xenctrl.h | 4 ++
tools/libs/guest/xg_cpuid_x86.c | 90 +++++++++++++++++++++++++++++++++
2 files changed, 94 insertions(+)
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index ffb3024bfeb..fc8e4b28781 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -2596,6 +2596,10 @@ typedef struct cpu_policy *xc_cpu_policy_t;
xc_cpu_policy_t xc_cpu_policy_init(void);
void xc_cpu_policy_destroy(xc_cpu_policy_t policy);
+/* Retrieve a system policy, or get/set a domains policy. */
+int xc_cpu_policy_get_system(xc_interface *xch, unsigned int idx,
+ xc_cpu_policy_t policy);
+
int xc_get_cpu_levelling_caps(xc_interface *xch, uint32_t *caps);
int xc_get_cpu_featureset(xc_interface *xch, uint32_t index,
uint32_t *nr_features, uint32_t *featureset);
diff --git a/tools/libs/guest/xg_cpuid_x86.c b/tools/libs/guest/xg_cpuid_x86.c
index ade5281c178..3710fb63839 100644
--- a/tools/libs/guest/xg_cpuid_x86.c
+++ b/tools/libs/guest/xg_cpuid_x86.c
@@ -687,3 +687,93 @@ void xc_cpu_policy_destroy(xc_cpu_policy_t policy)
free(policy->msr);
free(policy);
}
+
+static int allocate_buffers(xc_interface *xch,
+ unsigned int *nr_leaves, xen_cpuid_leaf_t **leaves,
+ unsigned int *nr_msrs, xen_msr_entry_t **msrs)
+{
+ int rc;
+
+ *leaves = NULL;
+ *msrs = NULL;
+
+ rc = xc_cpu_policy_get_size(xch, nr_leaves, nr_msrs);
+ if ( rc )
+ {
+ PERROR("Failed to obtain policy info size");
+ return -errno;
+ }
+
+ *leaves = calloc(*nr_leaves, sizeof(**leaves));
+ *msrs = calloc(*nr_msrs, sizeof(**msrs));
+ if ( !*leaves || !*msrs )
+ {
+ PERROR("Failed to allocate resources");
+ free(*leaves);
+ free(*msrs);
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int deserialize_policy(xc_interface *xch, xc_cpu_policy_t policy,
+ unsigned int nr_leaves,
+ const xen_cpuid_leaf_t *leaves,
+ unsigned int nr_msrs, const xen_msr_entry_t
*msrs)
+{
+ uint32_t err_leaf = -1, err_subleaf = -1, err_msr = -1;
+ int rc;
+
+ rc = x86_cpuid_copy_from_buffer(policy->cpuid, leaves, nr_leaves,
+ &err_leaf, &err_subleaf);
+ if ( rc )
+ {
+ ERROR("Failed to deserialise CPUID (err leaf %#x, subleaf %#x) (%d =
%s)",
+ err_leaf, err_subleaf, -rc, strerror(-rc));
+ return rc;
+ }
+
+ rc = x86_msr_copy_from_buffer(policy->msr, msrs, nr_msrs, &err_msr);
+ if ( rc )
+ {
+ ERROR("Failed to deserialise MSR (err MSR %#x) (%d = %s)",
+ err_msr, -rc, strerror(-rc));
+ return rc;
+ }
+
+ return 0;
+}
+
+int xc_cpu_policy_get_system(xc_interface *xch, unsigned int idx,
+ xc_cpu_policy_t policy)
+{
+ unsigned int nr_leaves, nr_msrs;
+ xen_cpuid_leaf_t *leaves = NULL;
+ xen_msr_entry_t *msrs = NULL;
+ int rc;
+
+ rc = allocate_buffers(xch, &nr_leaves, &leaves, &nr_msrs, &msrs);
+ if ( rc )
+ {
+ errno = -rc;
+ return -1;
+ }
+
+ rc = xc_get_system_cpu_policy(xch, idx, &nr_leaves, leaves, &nr_msrs,
msrs);
+ if ( rc )
+ {
+ PERROR("Failed to obtain %u policy", idx);
+ rc = -1;
+ goto out;
+ }
+
+ rc = deserialize_policy(xch, policy, nr_leaves, leaves, nr_msrs, msrs);
+ if ( rc )
+ errno = -rc;
+
+ out:
+ free(leaves);
+ free(msrs);
+ return rc;
+}
--
2.30.1
