I want to change sync_core() to use MOV to CR2, but that won't work
the way we want on Xen PV, and the easiest fix is to make
sync_core() be a paravirt op. Make it so.
A real paravirt guru could probably microoptimize this. I doubt it
matters much, though, as sync_core() is mostly used during boot.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
arch/x86/include/asm/paravirt.h | 5 +++++
arch/x86/include/asm/paravirt_types.h | 2 ++
arch/x86/include/asm/processor.h | 3 ++-
arch/x86/kernel/paravirt.c | 2 ++
4 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index ce932812f142..7e76b72aa698 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -28,6 +28,11 @@ static inline void __cpuid(unsigned int *eax, unsigned int
*ebx,
PVOP_VCALL4(pv_cpu_ops.cpuid, eax, ebx, ecx, edx);
}
+static inline void sync_core(void)
+{
+ PVOP_VCALL0(pv_cpu_ops.sync_core);
+}
+
/*
* These special macros can be used to get or set a debugging register
*/
diff --git a/arch/x86/include/asm/paravirt_types.h
b/arch/x86/include/asm/paravirt_types.h
index 0f400c0e4979..e4d2cb2c0165 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -177,6 +177,8 @@ struct pv_cpu_ops {
void (*start_context_switch)(struct task_struct *prev);
void (*end_context_switch)(struct task_struct *next);
+
+ void (*sync_core)(void);
};
struct pv_irq_ops {
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 64fbc937d586..c4402053c663 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -507,6 +507,7 @@ static inline void load_sp0(struct tss_struct *tss,
}
#define set_iopl_mask native_set_iopl_mask
+#define sync_core native_sync_core
#endif /* CONFIG_PARAVIRT */
/* Free all resources held by a thread. */
@@ -591,7 +592,7 @@ static __always_inline void cpu_relax(void)
#define cpu_relax_lowlatency() cpu_relax()
/* Stop speculative execution and prefetching of modified code. */
-static inline void sync_core(void)
+static inline void native_sync_core(void)
{
int tmp;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index bbf3d5933eaa..4d6a20ecbc78 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -373,6 +373,8 @@ __visible struct pv_cpu_ops pv_cpu_ops = {
.start_context_switch = paravirt_nop,
.end_context_switch = paravirt_nop,
+
+ .sync_core = native_sync_core,
};
/* At this point, native_get/set_debugreg has real function entries */
--
2.9.3
