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-rw-r--r--xen/arch/i386/process.c149
1 files changed, 45 insertions, 104 deletions
diff --git a/xen/arch/i386/process.c b/xen/arch/i386/process.c
index 8665961b1e..ec381167ff 100644
--- a/xen/arch/i386/process.c
+++ b/xen/arch/i386/process.c
@@ -31,11 +31,6 @@
#include <xeno/irq.h>
#include <xeno/event.h>
-#define GET_SYSCALL_REGS(_p) \
- (((struct pt_regs *)(THREAD_SIZE + (unsigned long)(_p))) - 1)
-
-asmlinkage void ret_from_newdomain(void) __asm__("ret_from_newdomain");
-
int hlt_counter;
void disable_hlt(void)
@@ -63,16 +58,21 @@ static void default_idle(void)
}
}
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle (void)
+void continue_cpu_idle_loop(void)
{
int cpu = smp_processor_id();
+ for ( ; ; )
+ {
+ irq_stat[cpu].idle_timestamp = jiffies;
+ while (!current->hyp_events && !softirq_pending(cpu))
+ default_idle();
+ do_hyp_events();
+ do_softirq();
+ }
+}
+void startup_cpu_idle_loop(void)
+{
/* Just some sanity to ensure that the scheduler is set up okay. */
ASSERT(current->domain == IDLE_DOMAIN_ID);
(void)wake_up(current);
@@ -85,14 +85,7 @@ void cpu_idle (void)
smp_mb();
init_idle();
- for ( ; ; )
- {
- irq_stat[cpu].idle_timestamp = jiffies;
- while (!current->hyp_events && !softirq_pending(cpu))
- default_idle();
- do_hyp_events();
- do_softirq();
- }
+ continue_cpu_idle_loop();
}
static long no_idt[2];
@@ -186,43 +179,6 @@ void machine_power_off(void)
machine_restart(0);
}
-extern void show_trace(unsigned long* esp);
-
-void show_regs(struct pt_regs * regs)
-{
- unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
-
- printk("\n");
- printk("EIP: %04x:[<%08lx>] CPU: %d",0xffff & regs->xcs,regs->eip, smp_processor_id());
- if (regs->xcs & 3)
- printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
- printk(" EFLAGS: %08lx\n",regs->eflags);
- printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
- regs->eax,regs->ebx,regs->ecx,regs->edx);
- printk("ESI: %08lx EDI: %08lx EBP: %08lx",
- regs->esi, regs->edi, regs->ebp);
- printk(" DS: %04x ES: %04x FS: %04x GS: %04x\n",
- 0xffff & regs->xds, 0xffff & regs->xes,
- 0xffff & regs->xfs, 0xffff & regs->xgs);
-
- __asm__("movl %%cr0, %0": "=r" (cr0));
- __asm__("movl %%cr2, %0": "=r" (cr2));
- __asm__("movl %%cr3, %0": "=r" (cr3));
- /* This could fault if %cr4 does not exist */
- __asm__("1: movl %%cr4, %0 \n"
- "2: \n"
- ".section __ex_table,\"a\" \n"
- ".long 1b,2b \n"
- ".previous \n"
- : "=r" (cr4): "0" (0));
- printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
- show_trace(&regs->esp);
-}
-
-
-/*
- * Free current thread data structures etc..
- */
void exit_thread(void)
{
/* nothing to do ... */
@@ -249,8 +205,7 @@ void new_thread(struct task_struct *p,
unsigned long start_stack,
unsigned long start_info)
{
- struct pt_regs *regs = GET_SYSCALL_REGS(p);
- memset(regs, 0, sizeof(*regs));
+ execution_context_t *ec = &p->shared_info->execution_context;
/*
* Initial register values:
@@ -260,20 +215,14 @@ void new_thread(struct task_struct *p,
* ESI = start_info
* [EAX,EBX,ECX,EDX,EDI,EBP are zero]
*/
- p->thread.fs = p->thread.gs = FLAT_RING1_DS;
- regs->xds = regs->xes = regs->xfs = regs->xgs = regs->xss = FLAT_RING1_DS;
- regs->xcs = FLAT_RING1_CS;
- regs->eip = start_pc;
- regs->esp = start_stack;
- regs->esi = start_info;
-
- p->thread.esp = (unsigned long) regs;
- p->thread.esp0 = (unsigned long) (regs+1);
-
- p->thread.eip = (unsigned long) ret_from_newdomain;
+ ec->ds = ec->es = ec->fs = ec->gs = ec->ss = FLAT_RING1_DS;
+ ec->cs = FLAT_RING1_CS;
+ ec->eip = start_pc;
+ ec->esp = start_stack;
+ ec->esi = start_info;
- __save_flags(regs->eflags);
- regs->eflags |= X86_EFLAGS_IF;
+ __save_flags(ec->eflags);
+ ec->eflags |= X86_EFLAGS_IF;
/* No fast trap at start of day. */
SET_DEFAULT_FAST_TRAP(&p->thread);
@@ -288,34 +237,21 @@ void new_thread(struct task_struct *p,
: /* no output */ \
:"r" (thread->debugreg[register]))
-/*
- * switch_to(x,yn) should switch tasks from x to y.
- *
- * We fsave/fwait so that an exception goes off at the right time
- * (as a call from the fsave or fwait in effect) rather than to
- * the wrong process. Lazy FP saving no longer makes any sense
- * with modern CPU's, and this simplifies a lot of things (SMP
- * and UP become the same).
- *
- * NOTE! We used to use the x86 hardware context switching. The
- * reason for not using it any more becomes apparent when you
- * try to recover gracefully from saved state that is no longer
- * valid (stale segment register values in particular). With the
- * hardware task-switch, there is no way to fix up bad state in
- * a reasonable manner.
- *
- * The fact that Intel documents the hardware task-switching to
- * be slow is a fairly red herring - this code is not noticeably
- * faster. However, there _is_ some room for improvement here,
- * so the performance issues may eventually be a valid point.
- * More important, however, is the fact that this allows us much
- * more flexibility.
- */
-/* NB. prev_p passed in %eax, next_p passed in %edx */
-void __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
+void switch_to(struct task_struct *prev_p, struct task_struct *next_p)
{
struct thread_struct *next = &next_p->thread;
struct tss_struct *tss = init_tss + smp_processor_id();
+ execution_context_t *stack_ec = get_execution_context();
+
+ __cli();
+
+ /* Switch guest general-register state. */
+ memcpy(&prev_p->shared_info->execution_context,
+ stack_ec,
+ sizeof(*stack_ec));
+ memcpy(stack_ec,
+ &next_p->shared_info->execution_context,
+ sizeof(*stack_ec));
unlazy_fpu(prev_p);
@@ -323,18 +259,22 @@ void __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
CLEAR_FAST_TRAP(&prev_p->thread);
SET_FAST_TRAP(&next_p->thread);
- tss->esp0 = next->esp0;
+ /* Switch the guest OS ring-1 stack. */
tss->esp1 = next->esp1;
tss->ss1 = next->ss1;
+ /* Switch page tables. */
+ __write_cr3_counted(pagetable_val(next_p->mm.pagetable));
+
+ set_current(next_p);
+
/* Switch GDT and LDT. */
__asm__ __volatile__ ("lgdt %0" : "=m" (*next_p->mm.gdt));
load_LDT();
- /*
- * Now maybe reload the debug registers
- */
- if (next->debugreg[7]){
+ /* Maybe switch the debug registers. */
+ if ( next->debugreg[7] )
+ {
loaddebug(next, 0);
loaddebug(next, 1);
loaddebug(next, 2);
@@ -344,13 +284,14 @@ void __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
loaddebug(next, 7);
}
+ __sti();
}
/* XXX Currently the 'domain' field is ignored! XXX */
long do_iopl(unsigned int domain, unsigned int new_io_pl)
{
- struct pt_regs *regs = GET_SYSCALL_REGS(current);
- regs->eflags = (regs->eflags & 0xffffcfff) | ((new_io_pl&3) << 12);
+ execution_context_t *ec = get_execution_context();
+ ec->eflags = (ec->eflags & 0xffffcfff) | ((new_io_pl&3) << 12);
return 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-03 08:21:14 +0000