x86/sysctl: Retrofit XEN_SYSCTL_cpu_featureset_{pv,hvm}_max

Featuresets are supposed to be disappearing when the CPU policy infrastructure
is complete, but that has taken longer than expected, and isn't going to be
complete imminently either.

In the meantime, Xen does have proper default/max featuresets, and xen-cpuid
can even get them via the XEN_SYSCTL_cpu_policy_* interface, but only knows
now to render them nicely via the featureset interface.

Differences between default and max are a frequent source of errors,
frequently too in secret leading up to an embargo, so extend the featureset
sysctl to allow xen-cpuid to render them all nicely.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@cloud.com>

diff --git a/tools/misc/xen-cpuid.c b/tools/misc/xen-cpuid.c
index 227df7352e2b88bd73040bcbbc73c108949b4e0d..37a7eaa8edfcfb4f1eddd36a9099e85fb2d65c56 100644 (file)
--- a/tools/misc/xen-cpuid.c
+++ b/tools/misc/xen-cpuid.c
@@ -247,10 +247,12 @@ static const struct {
 #define COL_ALIGN "18"
 
 static const char *const fs_names[] = {
-    [XEN_SYSCTL_cpu_featureset_host] = "Host",
-    [XEN_SYSCTL_cpu_featureset_raw]  = "Raw",
-    [XEN_SYSCTL_cpu_featureset_pv]   = "PV",
-    [XEN_SYSCTL_cpu_featureset_hvm]  = "HVM",
+    [XEN_SYSCTL_cpu_featureset_raw]     = "Raw",
+    [XEN_SYSCTL_cpu_featureset_host]    = "Host",
+    [XEN_SYSCTL_cpu_featureset_pv]      = "PV Default",
+    [XEN_SYSCTL_cpu_featureset_hvm]     = "HVM Default",
+    [XEN_SYSCTL_cpu_featureset_pv_max]  = "PV Max",
+    [XEN_SYSCTL_cpu_featureset_hvm_max] = "HVM Max",
 };
 
 static void dump_leaf(uint32_t leaf, const char *const *strs)

diff --git a/tools/ocaml/libs/xc/xenctrl.ml b/tools/ocaml/libs/xc/xenctrl.ml
index a59dee0938970e1109fe23a1a2cf5faa36fa2a6c..e4096bf92c1dd26d3473c47a4284d75febf4c7e9 100644 (file)
--- a/tools/ocaml/libs/xc/xenctrl.ml
+++ b/tools/ocaml/libs/xc/xenctrl.ml
@@ -370,7 +370,13 @@ external version_changeset: handle -> string = "stub_xc_version_changeset"
 external version_capabilities: handle -> string =
   "stub_xc_version_capabilities"
 
-type featureset_index = Featureset_raw | Featureset_host | Featureset_pv | Featureset_hvm
+type featureset_index =
+  | Featureset_raw
+  | Featureset_host
+  | Featureset_pv
+  | Featureset_hvm
+  | Featureset_pv_max
+  | Featureset_hvm_max
 external get_cpu_featureset : handle -> featureset_index -> int64 array = "stub_xc_get_cpu_featureset"
 
 external watchdog : handle -> int -> int32 -> int

diff --git a/tools/ocaml/libs/xc/xenctrl.mli b/tools/ocaml/libs/xc/xenctrl.mli
index 3154e90f4f98d8850c256d3e05625df2419403c7..ef22545374304a1bb577d4122333c695b2903c0b 100644 (file)
--- a/tools/ocaml/libs/xc/xenctrl.mli
+++ b/tools/ocaml/libs/xc/xenctrl.mli
@@ -297,7 +297,13 @@ external version_changeset : handle -> string = "stub_xc_version_changeset"
 external version_capabilities : handle -> string
   = "stub_xc_version_capabilities"
 
-type featureset_index = Featureset_raw | Featureset_host | Featureset_pv | Featureset_hvm
+type featureset_index =
+  | Featureset_raw
+  | Featureset_host
+  | Featureset_pv
+  | Featureset_hvm
+  | Featureset_pv_max
+  | Featureset_hvm_max
 external get_cpu_featureset : handle -> featureset_index -> int64 array = "stub_xc_get_cpu_featureset"
 
 external pages_to_kib : int64 -> int64 = "stub_pages_to_kib"

diff --git a/xen/arch/x86/sysctl.c b/xen/arch/x86/sysctl.c
index f42a3b843ba747fc4fc910d4b9d8857b839f448c..6600eb43471b21248f91459df6f068ff3051897a 100644 (file)
--- a/xen/arch/x86/sysctl.c
+++ b/xen/arch/x86/sysctl.c
@@ -323,14 +323,16 @@ long arch_do_sysctl(
 
     case XEN_SYSCTL_get_cpu_featureset:
     {
-        static const struct cpuid_policy *const policy_table[4] = {
+        static const struct cpuid_policy *const policy_table[6] = {
             [XEN_SYSCTL_cpu_featureset_raw]  = &raw_cpuid_policy,
             [XEN_SYSCTL_cpu_featureset_host] = &host_cpuid_policy,
 #ifdef CONFIG_PV
             [XEN_SYSCTL_cpu_featureset_pv]   = &pv_def_cpuid_policy,
+            [XEN_SYSCTL_cpu_featureset_pv_max] = &pv_max_cpuid_policy,
 #endif
 #ifdef CONFIG_HVM
             [XEN_SYSCTL_cpu_featureset_hvm]  = &hvm_def_cpuid_policy,
+            [XEN_SYSCTL_cpu_featureset_hvm_max] = &hvm_max_cpuid_policy,
 #endif
         };
         const struct cpuid_policy *p = NULL;

diff --git a/xen/include/public/sysctl.h b/xen/include/public/sysctl.h
index 001a4de27375ae64c7e3e9f0cc76aae1ca26664a..e8dded9fb94af0d089db229f79f3b717b77e859b 100644 (file)
--- a/xen/include/public/sysctl.h
+++ b/xen/include/public/sysctl.h
@@ -796,6 +796,8 @@ struct xen_sysctl_cpu_featureset {
 #define XEN_SYSCTL_cpu_featureset_host     1
 #define XEN_SYSCTL_cpu_featureset_pv       2
 #define XEN_SYSCTL_cpu_featureset_hvm      3
+#define XEN_SYSCTL_cpu_featureset_pv_max   4
+#define XEN_SYSCTL_cpu_featureset_hvm_max  5
     uint32_t index;       /* IN: Which featureset to query? */
     uint32_t nr_features; /* IN/OUT: Number of entries in/written to
                            * 'features', or the maximum number of features if