direct-io.hg

view extras/mini-os/traps.c @ 7172:9c6b39746b78

Fix localhost live migration. We were overvigorously wiping out the store
entries when a domain closed and on save, which meant that the /vm entries
disappeared when a localhost migration occurred. XendCheckpoint has had extra
exception handling and logging added. It also now calls back through
XendDomain.restore_,which has the correct locking semantics to prevent race
conditions during migration.

Added assertions to XendCheckpoint to ensure that the channels are set after
XendDomainInfo.restore. I don't see why they would not be, and the old code
meant that in the case that they were not, IntroduceDomain would not be called
on the new domain, breaking Xend restart.

relocate calls through XendDomain.domain_restore_fd rather than directly to
XendCheckpoint to isolate XendCheckpoint from the rest of the world, and to
allow XendDomain to pass itself into XendCheckpoint for a callback.

Simplify the XendCheckpoint / XendDomainInfo interlock, giving only two
states, OK and TERMINATED. If XendCheckpoint asks for a suspend, but sees a
shutdown, it is valid for it to proceed -- either way the domain has stopped.
Higher level tools may wish to disallow this, but at the very least, there is
no sense in waiting for a suspend that will never come.

Signed-off-by: Ewan Mellor <ewan@xensource.com>
author emellor@ewan
date Tue Oct 04 11:14:50 2005 +0100 (2005-10-04)
parents 06d84bf87159
children c176d2e45117
line source
2 #include <os.h>
3 #include <traps.h>
4 #include <hypervisor.h>
5 #include <mm.h>
6 #include <lib.h>
8 /*
9 * These are assembler stubs in entry.S.
10 * They are the actual entry points for virtual exceptions.
11 */
12 void divide_error(void);
13 void debug(void);
14 void int3(void);
15 void overflow(void);
16 void bounds(void);
17 void invalid_op(void);
18 void device_not_available(void);
19 void coprocessor_segment_overrun(void);
20 void invalid_TSS(void);
21 void segment_not_present(void);
22 void stack_segment(void);
23 void general_protection(void);
24 void page_fault(void);
25 void coprocessor_error(void);
26 void simd_coprocessor_error(void);
27 void alignment_check(void);
28 void spurious_interrupt_bug(void);
29 void machine_check(void);
32 extern void do_exit(void);
34 void dump_regs(struct pt_regs *regs)
35 {
36 printk("FIXME: proper register dump (with the stack dump)\n");
37 }
40 static void do_trap(int trapnr, char *str, struct pt_regs * regs, unsigned long error_code)
41 {
42 printk("FATAL: Unhandled Trap %d (%s), error code=0x%lx\n", trapnr, str, error_code);
43 printk("Regs address %p\n", regs);
44 dump_regs(regs);
45 do_exit();
46 }
48 #define DO_ERROR(trapnr, str, name) \
49 void do_##name(struct pt_regs * regs, unsigned long error_code) \
50 { \
51 do_trap(trapnr, str, regs, error_code); \
52 }
54 #define DO_ERROR_INFO(trapnr, str, name, sicode, siaddr) \
55 void do_##name(struct pt_regs * regs, unsigned long error_code) \
56 { \
57 do_trap(trapnr, str, regs, error_code); \
58 }
60 DO_ERROR_INFO( 0, "divide error", divide_error, FPE_INTDIV, regs->eip)
61 DO_ERROR( 3, "int3", int3)
62 DO_ERROR( 4, "overflow", overflow)
63 DO_ERROR( 5, "bounds", bounds)
64 DO_ERROR_INFO( 6, "invalid operand", invalid_op, ILL_ILLOPN, regs->eip)
65 DO_ERROR( 7, "device not available", device_not_available)
66 DO_ERROR( 9, "coprocessor segment overrun", coprocessor_segment_overrun)
67 DO_ERROR(10, "invalid TSS", invalid_TSS)
68 DO_ERROR(11, "segment not present", segment_not_present)
69 DO_ERROR(12, "stack segment", stack_segment)
70 DO_ERROR_INFO(17, "alignment check", alignment_check, BUS_ADRALN, 0)
71 DO_ERROR(18, "machine check", machine_check)
73 void do_page_fault(struct pt_regs *regs, unsigned long error_code,
74 unsigned long addr)
75 {
76 printk("Page fault at linear address %p\n", addr);
77 dump_regs(regs);
78 #ifdef __x86_64__
79 /* FIXME: _PAGE_PSE */
80 {
81 unsigned long *tab = (unsigned long *)start_info.pt_base;
82 unsigned long page;
84 printk("Pagetable walk from %p:\n", tab);
86 page = tab[l4_table_offset(addr)];
87 tab = to_virt(mfn_to_pfn(pte_to_mfn(page)) << PAGE_SHIFT);
88 printk(" L4 = %p (%p)\n", page, tab);
90 page = tab[l3_table_offset(addr)];
91 tab = to_virt(mfn_to_pfn(pte_to_mfn(page)) << PAGE_SHIFT);
92 printk(" L3 = %p (%p)\n", page, tab);
94 page = tab[l2_table_offset(addr)];
95 tab = to_virt(mfn_to_pfn(pte_to_mfn(page)) << PAGE_SHIFT);
96 printk(" L2 = %p (%p)\n", page, tab);
98 page = tab[l1_table_offset(addr)];
99 printk(" L1 = %p\n", page);
100 }
101 #endif
102 do_exit();
103 }
105 void do_general_protection(struct pt_regs *regs, long error_code)
106 {
107 printk("GPF %p, error_code=%lx\n", regs, error_code);
108 dump_regs(regs);
109 do_exit();
110 }
113 void do_debug(struct pt_regs * regs)
114 {
115 printk("Debug exception\n");
116 #define TF_MASK 0x100
117 regs->eflags &= ~TF_MASK;
118 dump_regs(regs);
119 do_exit();
120 }
122 void do_coprocessor_error(struct pt_regs * regs)
123 {
124 printk("Copro error\n");
125 dump_regs(regs);
126 do_exit();
127 }
129 void simd_math_error(void *eip)
130 {
131 printk("SIMD error\n");
132 }
134 void do_simd_coprocessor_error(struct pt_regs * regs)
135 {
136 printk("SIMD copro error\n");
137 }
139 void do_spurious_interrupt_bug(struct pt_regs * regs)
140 {
141 }
143 /*
144 * Submit a virtual IDT to teh hypervisor. This consists of tuples
145 * (interrupt vector, privilege ring, CS:EIP of handler).
146 * The 'privilege ring' field specifies the least-privileged ring that
147 * can trap to that vector using a software-interrupt instruction (INT).
148 */
149 static trap_info_t trap_table[] = {
150 { 0, 0, __KERNEL_CS, (unsigned long)divide_error },
151 { 1, 0, __KERNEL_CS, (unsigned long)debug },
152 { 3, 3, __KERNEL_CS, (unsigned long)int3 },
153 { 4, 3, __KERNEL_CS, (unsigned long)overflow },
154 { 5, 3, __KERNEL_CS, (unsigned long)bounds },
155 { 6, 0, __KERNEL_CS, (unsigned long)invalid_op },
156 { 7, 0, __KERNEL_CS, (unsigned long)device_not_available },
157 { 9, 0, __KERNEL_CS, (unsigned long)coprocessor_segment_overrun },
158 { 10, 0, __KERNEL_CS, (unsigned long)invalid_TSS },
159 { 11, 0, __KERNEL_CS, (unsigned long)segment_not_present },
160 { 12, 0, __KERNEL_CS, (unsigned long)stack_segment },
161 { 13, 0, __KERNEL_CS, (unsigned long)general_protection },
162 { 14, 0, __KERNEL_CS, (unsigned long)page_fault },
163 { 15, 0, __KERNEL_CS, (unsigned long)spurious_interrupt_bug },
164 { 16, 0, __KERNEL_CS, (unsigned long)coprocessor_error },
165 { 17, 0, __KERNEL_CS, (unsigned long)alignment_check },
166 { 18, 0, __KERNEL_CS, (unsigned long)machine_check },
167 { 19, 0, __KERNEL_CS, (unsigned long)simd_coprocessor_error },
168 { 0, 0, 0, 0 }
169 };
173 void trap_init(void)
174 {
175 HYPERVISOR_set_trap_table(trap_table);
176 }