x86/paravirt: add sysret/sysexit pvops for returning to 32-bit compatibility userspace

In a 64-bit system, we need separate sysret/sysexit operations to
return to a 32-bit userspace.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citirx.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 3 deletions

diff --git a/include/asm-x86/irqflags.h b/include/asm-x86/irqflags.h
index 544836c96b61..ea9bd2635d59 100644
--- a/include/asm-x86/irqflags.h
+++ b/include/asm-x86/irqflags.h
@@ -112,9 +112,17 @@ static inline unsigned long __raw_local_irq_save(void)
 
 #ifdef CONFIG_X86_64
 #define INTERRUPT_RETURN        iretq
-#define USERGS_SYSRET                                   \
-                        swapgs;                         \
-                        sysretq;
+#define USERGS_SYSRET64                         \
+        swapgs;                                 \
+        sysretq;
+#define USERGS_SYSRET32                         \
+        swapgs;                                 \
+        sysretl
+#define ENABLE_INTERRUPTS_SYSEXIT32             \
+        swapgs;                                 \
+        sti;                                    \
+        sysexit
+
 #else
 #define INTERRUPT_RETURN                iret
 #define ENABLE_INTERRUPTS_SYSEXIT       sti; sysexit