[PATCH RFC 24/31] tools/stubs: Expose host levelling capabilities to userspace

[Andrew Cooper <andrew.cooper3@citrix.com>]

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: David Scott <dave@recoil.org>
CC: Rob Hoes <Rob.Hoes@citrix.com>
---
 tools/libxc/include/xenctrl.h       |  2 ++
 tools/libxc/xc_misc.c               | 14 ++++++++++++++
 tools/ocaml/libs/xc/xenctrl.ml      |  2 ++
 tools/ocaml/libs/xc/xenctrl.mli     |  2 ++
 tools/ocaml/libs/xc/xenctrl_stubs.c | 20 ++++++++++++++++++++
 5 files changed, 40 insertions(+)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index b44aec7..401a6f8 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -2843,6 +2843,8 @@ int xc_psr_cat_get_domain_data(xc_interface *xch, uint32_t domid,
 int xc_psr_cat_get_l3_info(xc_interface *xch, uint32_t socket,
                            uint32_t *cos_max, uint32_t *cbm_len);
 
+int xc_get_levelling_caps(xc_interface *xch, uint64_t *caps);
+
 int xc_get_featureset(xc_interface *xch, uint32_t index,
                       uint32_t *nr_features, uint32_t *featureset);
 #endif
diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
index 4d7af3d..7707a70 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -745,6 +745,20 @@ int xc_get_featureset(xc_interface *xch, uint32_t index,
     return ret;
 }
 
+int xc_get_levelling_caps(xc_interface *xch, uint64_t *caps)
+{
+    DECLARE_SYSCTL;
+    int ret;
+
+    sysctl.cmd = XEN_SYSCTL_get_levelling_caps;
+    ret = do_sysctl(xch, &sysctl);
+
+    if ( !ret )
+        *caps = sysctl.u.levelling.caps;
+
+    return ret;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/ocaml/libs/xc/xenctrl.ml b/tools/ocaml/libs/xc/xenctrl.ml
index 15c7eb0..d651533 100644
--- a/tools/ocaml/libs/xc/xenctrl.ml
+++ b/tools/ocaml/libs/xc/xenctrl.ml
@@ -247,6 +247,8 @@ external version_capabilities: handle -> string =
 type featureset_index = Featureset_host | Featureset_pv | Featureset_hvm
 external get_featureset : handle -> featureset_index -> int64 array = "stub_xc_get_featureset"
 
+external get_levelling_caps : handle -> int64 = "stub_xc_get_levelling_caps"
+
 external watchdog : handle -> int -> int32 -> int
   = "stub_xc_watchdog"
 
diff --git a/tools/ocaml/libs/xc/xenctrl.mli b/tools/ocaml/libs/xc/xenctrl.mli
index 42d6199..1342a5e 100644
--- a/tools/ocaml/libs/xc/xenctrl.mli
+++ b/tools/ocaml/libs/xc/xenctrl.mli
@@ -152,6 +152,8 @@ external version_capabilities : handle -> string
 type featureset_index = Featureset_host | Featureset_pv | Featureset_hvm
 external get_featureset : handle -> featureset_index -> int64 array = "stub_xc_get_featureset"
 
+external get_levelling_caps : handle -> int64 = "stub_xc_get_levelling_caps"
+
 type core_magic = Magic_hvm | Magic_pv
 type core_header = {
   xch_magic : core_magic;
diff --git a/tools/ocaml/libs/xc/xenctrl_stubs.c b/tools/ocaml/libs/xc/xenctrl_stubs.c
index a47473b..3ae2060 100644
--- a/tools/ocaml/libs/xc/xenctrl_stubs.c
+++ b/tools/ocaml/libs/xc/xenctrl_stubs.c
@@ -1255,6 +1255,26 @@ CAMLprim value stub_xc_get_featureset(value xch, value idx)
 	CAMLreturn(bitmap_val);
 }
 
+CAMLprim value stub_xc_get_levelling_caps(value xch)
+{
+	CAMLparam1(xch);
+
+	/* Safe, because of the global ocaml lock. */
+	static uint64_t caps;
+	static bool have_caps;
+
+	if (!have_caps)
+	{
+		int ret = xc_get_levelling_caps(_H(xch), &caps);
+
+		if (ret || (caps > INT64_MAX))
+			failwith_xc(_H(xch));
+		have_caps = true;
+	}
+
+	CAMLreturn(caml_copy_int64(caps));
+}
+
 CAMLprim value stub_xc_watchdog(value xch, value domid, value timeout)
 {
 	CAMLparam3(xch, domid, timeout);
-- 
2.1.4