x86/paravirt, 64-bit: add adjust_exception_frame

64-bit Xen pushes a couple of extra words onto an exception frame.
Add a hook to deal with them.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.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>

arch/x86/kernel/asm-offsets_64.c

@@ -61,6 +61,7 @@ int main(void)
 	OFFSET(PARAVIRT_PATCH_pv_irq_ops, paravirt_patch_template, pv_irq_ops);
 	OFFSET(PV_IRQ_irq_disable, pv_irq_ops, irq_disable);
 	OFFSET(PV_IRQ_irq_enable, pv_irq_ops, irq_enable);
+	OFFSET(PV_IRQ_adjust_exception_frame, pv_irq_ops, adjust_exception_frame);
 	OFFSET(PV_CPU_iret, pv_cpu_ops, iret);
 	OFFSET(PV_CPU_usergs_sysret32, pv_cpu_ops, usergs_sysret32);
 	OFFSET(PV_CPU_usergs_sysret64, pv_cpu_ops, usergs_sysret64);

arch/x86/kernel/entry_64.S

@@ -736,6 +736,7 @@ END(spurious_interrupt)
  */ 		
 	.macro zeroentry sym
 	INTR_FRAME
+	PARAVIRT_ADJUST_EXCEPTION_FRAME
 	pushq $0	/* push error code/oldrax */ 
 	CFI_ADJUST_CFA_OFFSET 8
 	pushq %rax	/* push real oldrax to the rdi slot */ 
@@ -748,6 +749,7 @@ END(spurious_interrupt)
 
 	.macro errorentry sym
 	XCPT_FRAME
+	PARAVIRT_ADJUST_EXCEPTION_FRAME
 	pushq %rax
 	CFI_ADJUST_CFA_OFFSET 8
 	CFI_REL_OFFSET rax,0

arch/x86/kernel/paravirt.c

@@ -296,6 +296,9 @@ struct pv_irq_ops pv_irq_ops = {
 	.irq_enable = native_irq_enable,
 	.safe_halt = native_safe_halt,
 	.halt = native_halt,
+#ifdef CONFIG_X86_64
+	.adjust_exception_frame = paravirt_nop,
+#endif
 };
 
 struct pv_cpu_ops pv_cpu_ops = {

arch/x86/xen/enlighten.c

@@ -1123,6 +1123,9 @@ static const struct pv_irq_ops xen_irq_ops __initdata = {
 	.irq_enable = xen_irq_enable,
 	.safe_halt = xen_safe_halt,
 	.halt = xen_halt,
+#ifdef CONFIG_X86_64
+	.adjust_exception_frame = paravirt_nop,
+#endif
 };
 
 static const struct pv_apic_ops xen_apic_ops __initdata = {

include/asm-x86/paravirt.h

@@ -189,6 +189,10 @@ struct pv_irq_ops {
 	void (*irq_enable)(void);
 	void (*safe_halt)(void);
 	void (*halt)(void);
+
+#ifdef CONFIG_X86_64
+	void (*adjust_exception_frame)(void);
+#endif
 };
 
 struct pv_apic_ops {
@@ -1544,6 +1548,11 @@ static inline unsigned long __raw_local_irq_save(void)
 	movq %rax, %rcx;				\
 	xorq %rax, %rax;
 
+#define PARAVIRT_ADJUST_EXCEPTION_FRAME					\
+	PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \
+		  CLBR_NONE,						\
+		  call PARA_INDIRECT(pv_irq_ops+PV_IRQ_adjust_exception_frame))
+
 #define USERGS_SYSRET64							\
 	PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret64),	\
 		  CLBR_NONE,						\

include/asm-x86/processor.h

@@ -532,6 +532,8 @@ static inline void load_sp0(struct tss_struct *tss,
 
 #define set_iopl_mask native_set_iopl_mask
 #define SWAPGS	swapgs
+
+#define PARAVIRT_ADJUST_EXCEPTION_FRAME	/*  */
 #endif /* CONFIG_PARAVIRT */
 
 /*