xen: add basic support for runtime parameter changing

Add the needed infrastructure for runtime parameter changing similar
to that used at boot time via cmdline. We are using the same parsing
functions as for cmdline parsing, but with a different array of
parameter definitions.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/arm/xen.lds.S b/xen/arch/arm/xen.lds.S
index 2d54f224ec436a7f8f02409e8cb45beb1ed13315..c9b9546435e76a7bc6773795a7d020539a589f9e 100644 (file)
--- a/xen/arch/arm/xen.lds.S
+++ b/xen/arch/arm/xen.lds.S
@@ -61,6 +61,10 @@ SECTIONS
        *(.lockprofile.data)
        __lock_profile_end = .;
 #endif
+       . = ALIGN(POINTER_ALIGN);
+       __param_start = .;
+       *(.data.param)
+       __param_end = .;
   } :text
 
 #if defined(BUILD_ID)

diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S
index e48ab6a1ad17f034fbab66e6d8d5b02059a6dea0..d5e8821d41eb8315da3710d859c00584a6a5ead9 100644 (file)
--- a/xen/arch/x86/xen.lds.S
+++ b/xen/arch/x86/xen.lds.S
@@ -120,6 +120,10 @@ SECTIONS
        *(.lockprofile.data)
        __lock_profile_end = .;
 #endif
+       . = ALIGN(POINTER_ALIGN);
+       __param_start = .;
+       *(.data.param)
+       __param_end = .;
   } :text
 
 #if defined(BUILD_ID)

diff --git a/xen/common/kernel.c b/xen/common/kernel.c
index 6e2f5ed9da0aea1fbf6257f1c09bb68f916c2729..f96e402515c5fb3eb68c7b3d3996938ee76b7cc5 100644 (file)
--- a/xen/common/kernel.c
+++ b/xen/common/kernel.c
@@ -192,6 +192,11 @@ static void __init _cmdline_parse(const char *cmdline)
     parse_params(cmdline, __setup_start, __setup_end);
 }
 
+int runtime_parse(const char *line)
+{
+    return parse_params(line, __param_start, __param_end);
+}
+
 /**
  *    cmdline_parse -- parses the xen command line.
  * If CONFIG_CMDLINE is set, it would be parsed prior to @cmdline.

diff --git a/xen/include/xen/init.h b/xen/include/xen/init.h
index 234ec25aae9e1b12599cc18d1bdd9f362d42327c..db06c76fdfb6d9358900c5f36438397ce74768f4 100644 (file)
--- a/xen/include/xen/init.h
+++ b/xen/include/xen/init.h
@@ -90,11 +90,16 @@ struct kernel_param {
 };
 
 extern const struct kernel_param __setup_start[], __setup_end[];
+extern const struct kernel_param __param_start[], __param_end[];
+
+#define __dataparam       __used_section(".data.param")
+
+#define __param(att)      static const att \
+    __attribute__((__aligned__(sizeof(void *)))) struct kernel_param
 
 #define __setup_str static const __initconst \
     __attribute__((__aligned__(1))) char
-#define __kparam static const __initsetup \
-    __attribute__((__aligned__(sizeof(void *)))) struct kernel_param
+#define __kparam          __param(__initsetup)
 
 #define custom_param(_name, _var) \
     __setup_str __setup_str_##_var[] = _name; \
@@ -131,6 +136,54 @@ extern const struct kernel_param __setup_start[], __setup_end[];
           .len = sizeof(_var), \
           .par.var = &_var }
 
+#define __rtparam         __param(__dataparam)
+
+#define custom_runtime_only_param(_name, _var) \
+    __rtparam __rtpar_##_var = \
+      { .name = _name, \
+          .type = OPT_CUSTOM, \
+          .par.func = _var }
+#define boolean_runtime_only_param(_name, _var) \
+    __rtparam __rtpar_##_var = \
+        { .name = _name, \
+          .type = OPT_BOOL, \
+          .len = sizeof(_var), \
+          .par.var = &_var }
+#define integer_runtime_only_param(_name, _var) \
+    __rtparam __rtpar_##_var = \
+        { .name = _name, \
+          .type = OPT_UINT, \
+          .len = sizeof(_var), \
+          .par.var = &_var }
+#define size_runtime_only_param(_name, _var) \
+    __rtparam __rtpar_##_var = \
+        { .name = _name, \
+          .type = OPT_SIZE, \
+          .len = sizeof(_var), \
+          .par.var = &_var }
+#define string_runtime_only_param(_name, _var) \
+    __rtparam __rtpar_##_var = \
+        { .name = _name, \
+          .type = OPT_STR, \
+          .len = sizeof(_var), \
+          .par.var = &_var }
+
+#define custom_runtime_param(_name, _var) \
+    custom_param(_name, _var); \
+    custom_runtime_only_param(_name, _var)
+#define boolean_runtime_param(_name, _var) \
+    boolean_param(_name, _var); \
+    boolean_runtime_only_param(_name, _var)
+#define integer_runtime_param(_name, _var) \
+    integer_param(_name, _var); \
+    integer_runtime_only_param(_name, _var)
+#define size_runtime_param(_name, _var) \
+    size_param(_name, _var); \
+    size_runtime_only_param(_name, _var)
+#define string_runtime_param(_name, _var) \
+    string_param(_name, _var); \
+    string_runtime_only_param(_name, _var)
+
 #endif /* __ASSEMBLY__ */
 
 #ifdef CONFIG_LATE_HWDOM

diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 8e57bbd0212cf66ddc6387fa460cb0524d060c05..ed00ae13793763135be9e6b39c6908ce8590dc3e 100644 (file)
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -71,6 +71,7 @@
 struct domain;
 
 void cmdline_parse(const char *cmdline);
+int runtime_parse(const char *line);
 int parse_bool(const char *s, const char *e);
 
 /*#define DEBUG_TRACE_DUMP*/