x86: adds paravirt hook for swapgs

This patch adds paravirt hook for swapgs operation, which is a privileged
operation in x86_64.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h
index e6fa06fee72a..72740c6f1109 100644
--- a/include/asm-x86/processor.h
+++ b/include/asm-x86/processor.h
@@ -435,6 +435,13 @@ static inline void native_load_sp0(struct tss_struct *tss,
 #endif
 }
 
+static inline void native_swapgs(void)
+{
+#ifdef CONFIG_X86_64
+        asm volatile("swapgs" ::: "memory");
+#endif
+}
+
 #ifdef CONFIG_PARAVIRT
 #include <asm/paravirt.h>
 #else
@@ -456,6 +463,7 @@ static inline void load_sp0(struct tss_struct *tss,
 }
 
 #define set_iopl_mask native_set_iopl_mask
+#define SWAPGS  swapgs
 #endif /* CONFIG_PARAVIRT */
 
 /*