[PATCH v8 7/8] x86/time: add a domain context record for tsc_info...

[Paul Durrant <paul@xxxxxxx>]

From: Paul Durrant <pdurrant@xxxxxxxxxx>

... and update xen-domctx to dump some information describing the record.

NOTE: Whilst the record definition is x86 specific, it is visible directly
      in the common header as context record numbers should be unique across
      all architectures.

Signed-off-by: Paul Durrant <pdurrant@xxxxxxxxxx>
Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Wei Liu <wl@xxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <george.dunlap@xxxxxxxxxx>
Cc: Julien Grall <julien@xxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx>

v8:
 - Removed stray blank line

v7:
 - New in v7
---
 tools/misc/xen-domctx.c    | 11 +++++++++++
 xen/arch/x86/time.c        | 34 +++++++++++++++++++++++++++++++++-
 xen/include/asm-x86/time.h |  5 +++--
 xen/include/public/save.h  | 13 ++++++++++++-
 4 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/tools/misc/xen-domctx.c b/tools/misc/xen-domctx.c
index 6ead7ea89d..e582a79678 100644
--- a/tools/misc/xen-domctx.c
+++ b/tools/misc/xen-domctx.c
@@ -59,7 +59,17 @@ static void dump_header(void)
 
     printf("    HEADER: magic %#x, version %u\n",
            h->magic, h->version);
+}
+
+static void dump_tsc_info(void)
+{
+    DOMAIN_SAVE_TYPE(TSC_INFO) *t;
+
+    GET_PTR(t);
 
+    printf("    TSC_INFO: mode: %u incarnation: %u\n"
+           "              khz %u elapsed_nsec: %"PRIu64"\n",
+           t->mode, t->incarnation, t->khz, t->elapsed_nsec);
 }
 
 static void print_binary(const char *prefix, const void *val, size_t size,
@@ -251,6 +261,7 @@ int main(int argc, char **argv)
             {
             case DOMAIN_SAVE_CODE(HEADER): dump_header(); break;
             case DOMAIN_SAVE_CODE(SHARED_INFO): dump_shared_info(); break;
+            case DOMAIN_SAVE_CODE(TSC_INFO): dump_tsc_info(); break;
             case DOMAIN_SAVE_CODE(END): dump_end(); break;
             default:
                 printf("Unknown type %u: skipping\n", desc->typecode);
diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index 505e54ebd7..05f65fbf12 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -26,6 +26,7 @@
 #include <xen/symbols.h>
 #include <xen/keyhandler.h>
 #include <xen/guest_access.h>
+#include <xen/save.h>
 #include <asm/io.h>
 #include <asm/iocap.h>
 #include <asm/msr.h>
@@ -2334,7 +2335,7 @@ int host_tsc_is_safe(void)
  * called to collect tsc-related data only for save file or live
  * migrate; called after last rdtsc is done on this incarnation
  */
-void tsc_get_info(struct domain *d, uint32_t *tsc_mode,
+void tsc_get_info(const struct domain *d, uint32_t *tsc_mode,
                   uint64_t *elapsed_nsec, uint32_t *gtsc_khz,
                   uint32_t *incarnation)
 {
@@ -2453,6 +2454,37 @@ int tsc_set_info(struct domain *d,
     return 0;
 }
 
+static int save_tsc_info(const struct domain *d, struct domain_context *c,
+                         bool dry_run)
+{
+    struct domain_tsc_info_context ctxt;
+
+    if ( !dry_run )
+        tsc_get_info(d, &ctxt.mode, &ctxt.elapsed_nsec, &ctxt.khz,
+                     &ctxt.incarnation);
+
+    return DOMAIN_SAVE_ENTRY(TSC_INFO, c, 0, &ctxt, sizeof(ctxt));
+}
+
+static int load_tsc_info(struct domain *d, struct domain_context *c)
+{
+    struct domain_tsc_info_context ctxt;
+    unsigned int i;
+    int rc;
+
+    rc = DOMAIN_LOAD_ENTRY(TSC_INFO, c, &i, &ctxt, sizeof(ctxt));
+    if ( rc )
+        return rc;
+
+    if ( i ) /* expect only a single instance */
+        return -ENXIO;
+
+    return tsc_set_info(d, ctxt.mode, ctxt.elapsed_nsec, ctxt.khz,
+                        ctxt.incarnation);
+}
+
+DOMAIN_REGISTER_SAVE_LOAD(TSC_INFO, save_tsc_info, load_tsc_info);
+
 /* vtsc may incur measurable performance degradation, diagnose with this */
 static void dump_softtsc(unsigned char key)
 {
diff --git a/xen/include/asm-x86/time.h b/xen/include/asm-x86/time.h
index f347311cc4..7f2ce6226a 100644
--- a/xen/include/asm-x86/time.h
+++ b/xen/include/asm-x86/time.h
@@ -59,8 +59,9 @@ u64 gtsc_to_gtime(struct domain *d, u64 tsc);
 int tsc_set_info(struct domain *d, uint32_t tsc_mode, uint64_t elapsed_nsec,
                  uint32_t gtsc_khz, uint32_t incarnation);
 
-void tsc_get_info(struct domain *d, uint32_t *tsc_mode, uint64_t *elapsed_nsec,
-                  uint32_t *gtsc_khz, uint32_t *incarnation);
+void tsc_get_info(const struct domain *d, uint32_t *tsc_mode,
+                  uint64_t *elapsed_nsec, uint32_t *gtsc_khz,
+                  uint32_t *incarnation);
    
 
 void force_update_vcpu_system_time(struct vcpu *v);
diff --git a/xen/include/public/save.h b/xen/include/public/save.h
index 0e855a4b97..aeb17298eb 100644
--- a/xen/include/public/save.h
+++ b/xen/include/public/save.h
@@ -93,7 +93,18 @@ struct domain_shared_info_context {
 
 DECLARE_DOMAIN_SAVE_TYPE(SHARED_INFO, 2, struct domain_shared_info_context);
 
-#define DOMAIN_SAVE_CODE_MAX 2
+#if defined(__i386__) || defined(__x86_64__)
+struct domain_tsc_info_context {
+    uint32_t mode;
+    uint32_t incarnation;
+    uint64_t elapsed_nsec;
+    uint32_t khz;
+};
+
+DECLARE_DOMAIN_SAVE_TYPE(TSC_INFO, 3, struct domain_tsc_info_context);
+#endif
+
+#define DOMAIN_SAVE_CODE_MAX 3
 
 #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
 
-- 
2.20.1