[PATCH v5 1/2] xenoprof: fix up ability to disable it

[Doug Goldstein <cardoe@cardoe.com>]

Allow Xenoprof to be fully disabled when toggling the option off.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
---
CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <jbeulich@suse.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>

change since v4:
- as much as possible disabled by CONFIG_XENOPROF as suggested by Andrew Cooper
change since v3:
- drop (void)var; from static inlines
- fix typo that broke build (must have forgotten to do XEN_CONFIG_EXPERT=y make
change since v2:
- move all functions in xenoprof.h inside CONFIG_XENOPROF as suggested by
  Andrew Cooper
change since v1:
- switch to #define empty 'functions' as suggested by Andrew Cooper
---
 xen/arch/x86/Makefile              |  2 +-
 xen/arch/x86/Rules.mk              |  2 ++
 xen/arch/x86/x86_64/compat/entry.S |  4 ++++
 xen/arch/x86/x86_64/entry.S        |  4 ++++
 xen/include/asm-x86/config.h       |  1 -
 xen/include/asm-x86/xenoprof.h     | 21 +++++++++++++++++++++
 xen/include/xen/xenoprof.h         | 27 +++++++++++++++++++++------
 7 files changed, 53 insertions(+), 8 deletions(-)

diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 8e6e901..434d985 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -3,7 +3,7 @@ subdir-y += cpu
 subdir-y += genapic
 subdir-y += hvm
 subdir-y += mm
-subdir-y += oprofile
+subdir-$(xenoprof) += oprofile
 subdir-y += x86_64
 
 obj-bin-y += alternative.init.o
diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk
index a1cdae0..94e4efd 100644
--- a/xen/arch/x86/Rules.mk
+++ b/xen/arch/x86/Rules.mk
@@ -10,6 +10,8 @@ CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-generic
 CFLAGS += -I$(BASEDIR)/include/asm-x86/mach-default
 CFLAGS += '-D__OBJECT_LABEL__=$(subst /,$$,$(subst -,_,$(subst $(BASEDIR)/,,$(CURDIR))/$@))'
 
+CFLAGS-$(xenoprof) += -DCONFIG_XENOPROF
+
 # Prevent floating-point variables from creeping into Xen.
 CFLAGS += -msoft-float
 
diff --git a/xen/arch/x86/x86_64/compat/entry.S b/xen/arch/x86/x86_64/compat/entry.S
index 8cb8bca..927439d 100644
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -345,6 +345,10 @@ compat_crash_page_fault:
 #define compat_kexec_op do_ni_hypercall
 #endif
 
+#ifndef CONFIG_XENOPROF
+#define compat_xenoprof_op do_ni_hypercall
+#endif
+
 ENTRY(compat_hypercall_table)
         .quad compat_set_trap_table     /*  0 */
         .quad do_mmu_update
diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S
index fc81a93..e0f5c83 100644
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -682,6 +682,10 @@ ENTRY(exception_table)
 #define do_kexec_op do_ni_hypercall
 #endif
 
+#ifndef CONFIG_XENOPROF
+#define do_xenoprof_op do_ni_hypercall
+#endif
+
 ENTRY(hypercall_table)
         .quad do_set_trap_table     /*  0 */
         .quad do_mmu_update
diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index d97877d..a45d3ee 100644
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -47,7 +47,6 @@
 #define CONFIG_VGA 1
 #define CONFIG_VIDEO 1
 
-#define CONFIG_XENOPROF 1
 #define CONFIG_WATCHDOG 1
 
 #define CONFIG_MULTIBOOT 1
diff --git a/xen/include/asm-x86/xenoprof.h b/xen/include/asm-x86/xenoprof.h
index b006ddc..dca4223 100644
--- a/xen/include/asm-x86/xenoprof.h
+++ b/xen/include/asm-x86/xenoprof.h
@@ -22,6 +22,8 @@
 #ifndef __ASM_X86_XENOPROF_H__
 #define __ASM_X86_XENOPROF_H__
 
+#ifdef CONFIG_XENOPROF
+
 int nmi_reserve_counters(void);
 int nmi_setup_events(void);
 int nmi_enable_virq(void);
@@ -67,10 +69,29 @@ void xenoprof_backtrace(struct vcpu *, const struct cpu_user_regs *,
                  "xenoprof/x86 with autotranslated mode enabled"    \
                  "isn't supported yet\n");                          \
     } while (0)
+
 int passive_domain_do_rdmsr(unsigned int msr, uint64_t *msr_content);
 int passive_domain_do_wrmsr(unsigned int msr, uint64_t msr_content);
 void passive_domain_destroy(struct vcpu *v);
 
+#else
+
+static inline int passive_domain_do_rdmsr(unsigned int msr,
+                                          uint64_t *msr_content)
+{
+    return 0;
+}
+
+static inline int passive_domain_do_wrmsr(unsigned int msr,
+                                          uint64_t msr_content)
+{
+    return 0;
+}
+
+static inline void passive_domain_destroy(struct vcpu *v) {}
+
+#endif /* CONFIG_XENOPROF */
+
 #endif /* __ASM_X86_XENOPROF_H__ */
 
 /*
diff --git a/xen/include/xen/xenoprof.h b/xen/include/xen/xenoprof.h
index 9b9ef56..8f045ab 100644
--- a/xen/include/xen/xenoprof.h
+++ b/xen/include/xen/xenoprof.h
@@ -14,6 +14,12 @@
 #include <public/xenoprof.h>
 #include <asm/xenoprof.h>
 
+#define PMU_OWNER_NONE          0
+#define PMU_OWNER_XENOPROF      1
+#define PMU_OWNER_HVM           2
+
+#ifdef CONFIG_XENOPROF
+
 #define XENOPROF_DOMAIN_IGNORED    0
 #define XENOPROF_DOMAIN_ACTIVE     1
 #define XENOPROF_DOMAIN_PASSIVE    2
@@ -64,19 +70,28 @@ struct xenoprof {
 #endif
 
 struct domain;
+
+int acquire_pmu_ownership(int pmu_ownership);
+void release_pmu_ownership(int pmu_ownership);
+
 int is_active(struct domain *d);
 int is_passive(struct domain *d);
 void free_xenoprof_pages(struct domain *d);
 
 int xenoprof_add_trace(struct vcpu *, uint64_t pc, int mode);
 
-#define PMU_OWNER_NONE          0
-#define PMU_OWNER_XENOPROF      1
-#define PMU_OWNER_HVM           2
-int acquire_pmu_ownership(int pmu_ownership);
-void release_pmu_ownership(int pmu_ownership);
-
 void xenoprof_log_event(struct vcpu *, const struct cpu_user_regs *,
                         uint64_t pc, int mode, int event);
 
+#else
+static inline int acquire_pmu_ownership(int pmu_ownership)
+{
+    return 1;
+}
+
+static inline void release_pmu_ownership(int pmu_ownership)
+{
+}
+#endif /* CONFIG_XENOPROF */
+
 #endif  /* __XEN__XENOPROF_H__ */
-- 
2.4.10