[xen staging] tools/libx[cl]: Plumb bool restore down into xc_cpuid_apply_policy()

[patchbot@xxxxxxx]

commit 057012d2899e4e71e274f77fcab136b0cad23099
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Jun 12 14:07:10 2020 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Wed Jun 17 13:54:12 2020 +0100

    tools/libx[cl]: Plumb bool restore down into xc_cpuid_apply_policy()
    
    In order to safely disable some features by default, without breaking
    migration from 4.13 or older, the CPUID logic needs to distinguish the two
    cases.
    
    Plumb a restore boolean down from the two callers of libxl__cpuid_legacy() 
all
    the way down into xc_cpuid_apply_policy().
    
    No functional change.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
    Release-acked-by: Paul Durrant <paul@xxxxxxx>
---
 tools/libxc/include/xenctrl.h | 7 ++++++-
 tools/libxc/xc_cpuid_x86.c    | 2 +-
 tools/libxl/libxl_cpuid.c     | 4 ++--
 tools/libxl/libxl_create.c    | 2 +-
 tools/libxl/libxl_dom.c       | 2 +-
 tools/libxl/libxl_internal.h  | 2 +-
 tools/libxl/libxl_nocpuid.c   | 2 +-
 7 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index c1495553a5..4c89b7294c 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1822,13 +1822,18 @@ struct xc_xend_cpuid {
 /*
  * Make adjustments to the CPUID settings for a domain.
  *
+ * This path is used in two cases.  First, for fresh boots of the domain, and
+ * secondly for migrate-in/restore of pre-4.14 guests (where CPUID data was
+ * missing from the stream).  The @restore parameter distinguishes these
+ * cases, and the generated policy must be compatible with a 4.13.
+ *
  * Either pass a full new @featureset (and @nr_features), or adjust individual
  * features (@pae).
  *
  * Then (optionally) apply legacy XEND overrides (@xend) to the result.
  */
 int xc_cpuid_apply_policy(xc_interface *xch,
-                          uint32_t domid,
+                          uint32_t domid, bool restore,
                           const uint32_t *featureset,
                           unsigned int nr_features, bool pae,
                           const struct xc_xend_cpuid *xend);
diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c
index 77aab0854f..b6b5dc88a2 100644
--- a/tools/libxc/xc_cpuid_x86.c
+++ b/tools/libxc/xc_cpuid_x86.c
@@ -425,7 +425,7 @@ static int xc_cpuid_xend_policy(
     return rc;
 }
 
-int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid,
+int xc_cpuid_apply_policy(xc_interface *xch, uint32_t domid, bool restore,
                           const uint32_t *featureset, unsigned int nr_features,
                           bool pae,
                           const struct xc_xend_cpuid *xend)
diff --git a/tools/libxl/libxl_cpuid.c b/tools/libxl/libxl_cpuid.c
index edfcf315ca..db2f12d115 100644
--- a/tools/libxl/libxl_cpuid.c
+++ b/tools/libxl/libxl_cpuid.c
@@ -416,7 +416,7 @@ int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list 
*cpuid,
     return 0;
 }
 
-void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid,
+void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
                          libxl_domain_build_info *info)
 {
     bool pae = true;
@@ -434,7 +434,7 @@ void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid,
     if (info->type == LIBXL_DOMAIN_TYPE_HVM)
         pae = libxl_defbool_val(info->u.hvm.pae);
 
-    xc_cpuid_apply_policy(ctx->xch, domid, NULL, 0, pae, info->cpuid);
+    xc_cpuid_apply_policy(ctx->xch, domid, restore, NULL, 0, pae, info->cpuid);
 }
 
 static const char *input_names[2] = { "leaf", "subleaf" };
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 75862dc6ed..2814818e34 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -1447,7 +1447,7 @@ int libxl__srm_callout_callback_static_data_done(unsigned 
int missing,
      * stream doesn't contain any CPUID data.
      */
     if (missing & XGR_SDD_MISSING_CPUID)
-        libxl__cpuid_legacy(ctx, dcs->guest_domid, info);
+        libxl__cpuid_legacy(ctx, dcs->guest_domid, true, info);
 
     return 0;
 }
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index dd1aff89a3..f8661e90d4 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -391,7 +391,7 @@ int libxl__build_pre(libxl__gc *gc, uint32_t domid,
      * being migrated-in/restored have CPUID handled during the
      * static_data_done() callback. */
     if (!state->restore)
-        libxl__cpuid_legacy(ctx, domid, info);
+        libxl__cpuid_legacy(ctx, domid, false, info);
 
     return rc;
 }
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 79c2bf5f5e..94a23179d3 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -2056,7 +2056,7 @@ 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);
 
-_hidden void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid,
+_hidden void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool retore,
                                  libxl_domain_build_info *info);
 
 /* Calls poll() again - useful to check whether a signaled condition
diff --git a/tools/libxl/libxl_nocpuid.c b/tools/libxl/libxl_nocpuid.c
index 3f30e148be..f47336565b 100644
--- a/tools/libxl/libxl_nocpuid.c
+++ b/tools/libxl/libxl_nocpuid.c
@@ -34,7 +34,7 @@ int libxl_cpuid_parse_config_xend(libxl_cpuid_policy_list 
*cpuid,
     return 0;
 }
 
-void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid,
+void libxl__cpuid_legacy(libxl_ctx *ctx, uint32_t domid, bool restore,
                          libxl_domain_build_info *info)
 {
 }
--
generated by git-patchbot for /home/xen/git/xen.git#staging