1.1 --- a/linux-2.6.11-xen-sparse/arch/xen/i386/kernel/process.c	Fri Apr 01 13:37:55 2005 +0000
     1.2 +++ b/linux-2.6.11-xen-sparse/arch/xen/i386/kernel/process.c	Fri Apr 01 13:57:45 2005 +0000
     1.3 @@ -445,22 +445,7 @@ struct task_struct fastcall * __switch_t
     1.4  	physdev_op_t iopl_op, iobmp_op;
     1.5  	multicall_entry_t _mcl[8], *mcl = _mcl;
     1.6  
     1.7 -	/*
     1.8 -	 * Save away %fs and %gs. No need to save %es and %ds, as
     1.9 -	 * those are always kernel segments while inside the kernel.
    1.10 -	 */
    1.11 -	asm volatile("movl %%fs,%0":"=m" (*(int *)&prev->fs));
    1.12 -	asm volatile("movl %%gs,%0":"=m" (*(int *)&prev->gs));
    1.13 -
    1.14 -	/*
    1.15 -	 * We clobber FS and GS here so that we avoid a GPF when restoring
    1.16 -	 * previous task's FS/GS values in Xen when the LDT is switched.
    1.17 -	 */
    1.18 -	__asm__ __volatile__ ( 
    1.19 -		"xorl %%eax,%%eax; movl %%eax,%%fs; movl %%eax,%%gs" : : :
    1.20 -		"eax" );
    1.21 -
    1.22 -	/* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
    1.23 +        /* XEN NOTE: FS/GS saved in switch_mm(), not here. */
    1.24  
    1.25  	/*
    1.26  	 * This is basically '__unlazy_fpu', except that we queue a

     2.1 --- a/linux-2.6.11-xen-sparse/include/asm-xen/asm-i386/mmu_context.h	Fri Apr 01 13:37:55 2005 +0000
     2.2 +++ b/linux-2.6.11-xen-sparse/include/asm-xen/asm-i386/mmu_context.h	Fri Apr 01 13:57:45 2005 +0000
     2.3 @@ -16,13 +16,31 @@ void destroy_context(struct mm_struct *m
     2.4  
     2.5  static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
     2.6  {
     2.7 -#ifdef CONFIG_SMP
     2.8 +#if 0 /* XEN */
     2.9  	unsigned cpu = smp_processor_id();
    2.10  	if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK)
    2.11  		per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_LAZY;
    2.12  #endif
    2.13  }
    2.14  
    2.15 +#define prepare_arch_switch(rq,next)	__prepare_arch_switch()
    2.16 +#define finish_arch_switch(rq, next)	spin_unlock_irq(&(rq)->lock)
    2.17 +#define task_running(rq, p)		((rq)->curr == (p))
    2.18 +
    2.19 +static inline void __prepare_arch_switch(void)
    2.20 +{
    2.21 +	/*
    2.22 +	 * Save away %fs and %gs. No need to save %es and %ds, as those
    2.23 +	 * are always kernel segments while inside the kernel. Must
    2.24 +	 * happen before reload of cr3/ldt (i.e., not in __switch_to).
    2.25 +	 */
    2.26 +	__asm__ __volatile__ ( "movl %%fs,%0 ; movl %%gs,%1"
    2.27 +		: "=m" (*(int *)&current->thread.fs),
    2.28 +		  "=m" (*(int *)&current->thread.gs));
    2.29 +	__asm__ __volatile__ ( "movl %0,%%fs ; movl %0,%%gs"
    2.30 +		: : "r" (0) );
    2.31 +}
    2.32 +
    2.33  static inline void switch_mm(struct mm_struct *prev,
    2.34  			     struct mm_struct *next,
    2.35  			     struct task_struct *tsk)
    2.36 @@ -32,7 +50,7 @@ static inline void switch_mm(struct mm_s
    2.37  	if (likely(prev != next)) {
    2.38  		/* stop flush ipis for the previous mm */
    2.39  		cpu_clear(cpu, prev->cpu_vm_mask);
    2.40 -#ifdef CONFIG_SMP
    2.41 +#if 0 /* XEN */
    2.42  		per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
    2.43  		per_cpu(cpu_tlbstate, cpu).active_mm = next;
    2.44  #endif
    2.45 @@ -47,7 +65,7 @@ static inline void switch_mm(struct mm_s
    2.46  		if (unlikely(prev->context.ldt != next->context.ldt))
    2.47  			load_LDT_nolock(&next->context, cpu);
    2.48  	}
    2.49 -#ifdef CONFIG_SMP
    2.50 +#if 0 /* XEN */
    2.51  	else {
    2.52  		per_cpu(cpu_tlbstate, cpu).state = TLBSTATE_OK;
    2.53  		BUG_ON(per_cpu(cpu_tlbstate, cpu).active_mm != next);