diff mbox series

[09/10] plugins/api: split out time control helpers

Message ID 20250225110844.3296991-10-alex.bennee@linaro.org
State New
Headers show
Series plugins: reduce total number of build objects | expand

Commit Message

Alex Bennée Feb. 25, 2025, 11:08 a.m. UTC 
These are only usable in system mode where we control the timer. For
user-mode make them NOPs.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
---
 plugins/api-system.c | 34 ++++++++++++++++++++++++++++++++++
 plugins/api-user.c   | 17 +++++++++++++++++
 plugins/api.c        | 41 -----------------------------------------
 3 files changed, 51 insertions(+), 41 deletions(-)

Comments

Richard Henderson Feb. 25, 2025, 6:45 p.m. UTC | #1 
On 2/25/25 03:08, Alex Bennée wrote:
> These are only usable in system mode where we control the timer. For
> user-mode make them NOPs.
> 
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>   plugins/api-system.c | 34 ++++++++++++++++++++++++++++++++++
>   plugins/api-user.c   | 17 +++++++++++++++++
>   plugins/api.c        | 41 -----------------------------------------
>   3 files changed, 51 insertions(+), 41 deletions(-)

Code movement, so,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

> +static bool has_control;
> +static Error *migration_blocker;
> +
> +const void *qemu_plugin_request_time_control(void)
> +{
> +    if (!has_control) {
> +        has_control = true;
> +        error_setg(&migration_blocker,
> +                   "TCG plugin time control does not support migration");
> +        migrate_add_blocker(&migration_blocker, NULL);
> +        return &has_control;
> +    }
> +    return NULL;
> +}

But I'm really not a fan of either this API, or the duplication between has_control and 
migration_blocker != NULL.


r~
diff mbox series

Patch

diff --git a/plugins/api-system.c b/plugins/api-system.c
index 38560de342..cc190b167e 100644
--- a/plugins/api-system.c
+++ b/plugins/api-system.c
@@ -95,3 +95,37 @@  const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
         return g_intern_static_string("RAM");
     }
 }
+
+/*
+ * Time control
+ */
+static bool has_control;
+static Error *migration_blocker;
+
+const void *qemu_plugin_request_time_control(void)
+{
+    if (!has_control) {
+        has_control = true;
+        error_setg(&migration_blocker,
+                   "TCG plugin time control does not support migration");
+        migrate_add_blocker(&migration_blocker, NULL);
+        return &has_control;
+    }
+    return NULL;
+}
+
+static void advance_virtual_time__async(CPUState *cpu, run_on_cpu_data data)
+{
+    int64_t new_time = data.host_ulong;
+    qemu_clock_advance_virtual_time(new_time);
+}
+
+void qemu_plugin_update_ns(const void *handle, int64_t new_time)
+{
+    if (handle == &has_control) {
+        /* Need to execute out of cpu_exec, so bql can be locked. */
+        async_run_on_cpu(current_cpu,
+                         advance_virtual_time__async,
+                         RUN_ON_CPU_HOST_ULONG(new_time));
+    }
+}
diff --git a/plugins/api-user.c b/plugins/api-user.c
index 867b420339..28704a89e8 100644
--- a/plugins/api-user.c
+++ b/plugins/api-user.c
@@ -12,6 +12,7 @@ 
 
 #include "qemu/osdep.h"
 #include "qemu/plugin.h"
+#include "exec/log.h"
 
 /*
  * Virtual Memory queries - these are all NOPs for user-mode which
@@ -38,3 +39,19 @@  const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
 {
     return g_intern_static_string("Invalid");
 }
+
+/*
+ * Time control - for user mode the only real time is wall clock time
+ * so realistically all you can do in user mode is slow down execution
+ * which doesn't require the ability to mess with the clock.
+ */
+
+const void *qemu_plugin_request_time_control(void)
+{
+    return NULL;
+}
+
+void qemu_plugin_update_ns(const void *handle, int64_t new_time)
+{
+    qemu_log_mask(LOG_UNIMP, "user-mode can't control time");
+}
diff --git a/plugins/api.c b/plugins/api.c
index b04577424f..61480d3dc1 100644
--- a/plugins/api.c
+++ b/plugins/api.c
@@ -525,44 +525,3 @@  uint64_t qemu_plugin_u64_sum(qemu_plugin_u64 entry)
     return total;
 }
 
-/*
- * Time control
- */
-static bool has_control;
-#ifdef CONFIG_SOFTMMU
-static Error *migration_blocker;
-#endif
-
-const void *qemu_plugin_request_time_control(void)
-{
-    if (!has_control) {
-        has_control = true;
-#ifdef CONFIG_SOFTMMU
-        error_setg(&migration_blocker,
-                   "TCG plugin time control does not support migration");
-        migrate_add_blocker(&migration_blocker, NULL);
-#endif
-        return &has_control;
-    }
-    return NULL;
-}
-
-#ifdef CONFIG_SOFTMMU
-static void advance_virtual_time__async(CPUState *cpu, run_on_cpu_data data)
-{
-    int64_t new_time = data.host_ulong;
-    qemu_clock_advance_virtual_time(new_time);
-}
-#endif
-
-void qemu_plugin_update_ns(const void *handle, int64_t new_time)
-{
-#ifdef CONFIG_SOFTMMU
-    if (handle == &has_control) {
-        /* Need to execute out of cpu_exec, so bql can be locked. */
-        async_run_on_cpu(current_cpu,
-                         advance_virtual_time__async,
-                         RUN_ON_CPU_HOST_ULONG(new_time));
-    }
-#endif
-}