x86/paravirt, 64-bit: don't restore user rsp within sysret

There's no need to combine restoring the user rsp within the sysret
pvop, so split it out.  This makes the pvop's semantics closer to the
machine instruction.

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, 3 insertions, 3 deletions

diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 0056bc4c61a9..18447a373fbd 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -59,8 +59,7 @@
 #endif  
 
 #ifdef CONFIG_PARAVIRT
-ENTRY(native_usersp_sysret)
-        movq    %gs:pda_oldrsp,%rsp
+ENTRY(native_usergs_sysret)
         swapgs
         sysretq
 #endif /* CONFIG_PARAVIRT */
@@ -275,7 +274,8 @@ sysret_check:
         CFI_REGISTER    rip,rcx
         RESTORE_ARGS 0,-ARG_SKIP,1
         /*CFI_REGISTER  rflags,r11*/
-        USERSP_SYSRET
+        movq    %gs:pda_oldrsp, %rsp
+        USERGS_SYSRET
 
         CFI_RESTORE_STATE
         /* Handle reschedules */