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>
diff --git a/include/asm-x86/irqflags.h b/include/asm-x86/irqflags.h
index 99ee525..544836c 100644
--- a/include/asm-x86/irqflags.h
+++ b/include/asm-x86/irqflags.h
@@ -112,8 +112,7 @@
#ifdef CONFIG_X86_64
#define INTERRUPT_RETURN iretq
-#define USERSP_SYSRET \
- movq %gs:pda_oldrsp, %rsp; \
+#define USERGS_SYSRET \
swapgs; \
sysretq;
#else
diff --git a/include/asm-x86/paravirt.h b/include/asm-x86/paravirt.h
index 2668903..dad5b41 100644
--- a/include/asm-x86/paravirt.h
+++ b/include/asm-x86/paravirt.h
@@ -143,7 +143,7 @@
/* These three are jmp to, not actually called. */
void (*irq_enable_sysexit)(void);
- void (*usersp_sysret)(void);
+ void (*usergs_sysret)(void);
void (*iret)(void);
void (*swapgs)(void);
@@ -1505,10 +1505,10 @@
movq %rax, %rcx; \
xorq %rax, %rax;
-#define USERSP_SYSRET \
- PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usersp_sysret), \
+#define USERGS_SYSRET \
+ PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret), \
CLBR_NONE, \
- jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usersp_sysret))
+ jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret))
#endif
#endif /* __ASSEMBLY__ */