Commit 81e103f1 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

xen: use iret instruction all the time 



Change iret implementation to not be dependent on direct-access vcpu
structure.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c9cf39ae

arch/x86/xen/enlighten.c

+1 −2
Original line number Diff line number Diff line
@@ -890,7 +890,6 @@ void __init xen_setup_vcpu_info_placement(void) 
		pv_irq_ops.irq_disable = xen_irq_disable_direct;

		pv_irq_ops.irq_enable = xen_irq_enable_direct;

		pv_mmu_ops.read_cr2 = xen_read_cr2_direct;

		pv_cpu_ops.iret = xen_iret_direct;

	}

}
@@ -994,7 +993,7 @@ static const struct pv_cpu_ops xen_cpu_ops __initdata = { 
	.read_tsc = native_read_tsc,

	.read_pmc = native_read_pmc,



	.iret = (void *)&hypercall_page[__HYPERVISOR_iret],

	.iret = xen_iret,

	.irq_enable_syscall_ret = NULL,  /* never called */



	.load_tr_desc = paravirt_nop,

arch/x86/xen/xen-asm.S

+3 −8
Original line number Diff line number Diff line
@@ -135,13 +135,8 @@ ENDPATCH(xen_restore_fl_direct) 
	current stack state in whatever form its in, we keep things

	simple by only using a single register which is pushed/popped

	on the stack.



	Non-direct iret could be done in the same way, but it would

	require an annoying amount of code duplication.  We'll assume

	that direct mode will be the common case once the hypervisor

	support becomes commonplace.

 */

ENTRY(xen_iret_direct)

ENTRY(xen_iret)

	/* test eflags for special cases */

	testl $(X86_EFLAGS_VM | XEN_EFLAGS_NMI), 8(%esp)

	jnz hyper_iret
@@ -155,9 +150,9 @@ ENTRY(xen_iret_direct) 
	GET_THREAD_INFO(%eax)

	movl TI_cpu(%eax),%eax

	movl __per_cpu_offset(,%eax,4),%eax

	lea per_cpu__xen_vcpu_info(%eax),%eax

	mov per_cpu__xen_vcpu(%eax),%eax

#else

	movl $per_cpu__xen_vcpu_info, %eax

	movl per_cpu__xen_vcpu, %eax

#endif



	/* check IF state we're restoring */

arch/x86/xen/xen-ops.h

+1 −1
Original line number Diff line number Diff line
@@ -63,5 +63,5 @@ DECL_ASM(void, xen_irq_disable_direct, void); 
DECL_ASM(unsigned long, xen_save_fl_direct, void);

DECL_ASM(void, xen_restore_fl_direct, unsigned long);



void xen_iret_direct(void);

void xen_iret(void);

#endif /* XEN_OPS_H */