# HG changeset patch
# User Keir Fraser <keir@xxxxxxxxxxxxx>
# Date 1175868454 -3600
# Node ID f80a97d262769710f9e1612bebc3c1308f947e4e
# Parent bd73cb523111dd022d6d1e7de01d1930ed85b307
xen x86/64: Fix int80 direct trap. It must check for events and also
disable interrupts before exiting to guest context.
Also sprinkle about some assertions about interrupt-enable status.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
xen/arch/x86/x86_32/entry.S | 1 +
xen/arch/x86/x86_64/compat/entry.S | 4 +++-
xen/arch/x86/x86_64/entry.S | 6 ++++--
xen/arch/x86/x86_64/traps.c | 12 ++++++++----
xen/include/asm-x86/desc.h | 2 +-
xen/include/asm-x86/x86_32/asm_defns.h | 10 ++++++++++
xen/include/asm-x86/x86_64/asm_defns.h | 10 ++++++++++
7 files changed, 37 insertions(+), 8 deletions(-)
diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_32/entry.S
--- a/xen/arch/x86/x86_32/entry.S Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/arch/x86/x86_32/entry.S Fri Apr 06 15:07:34 2007 +0100
@@ -283,6 +283,7 @@ bad_hypercall:
/* %edx == trap_bounce, %ebx == struct vcpu */
/* %eax,%ecx are clobbered. %gs:%esi contain new UREGS_ss/UREGS_esp. */
create_bounce_frame:
+ ASSERT_INTERRUPTS_ENABLED
movl UREGS_eflags+4(%esp),%ecx
movb UREGS_cs+4(%esp),%cl
testl $(2|X86_EFLAGS_VM),%ecx
diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_64/compat/entry.S
--- a/xen/arch/x86/x86_64/compat/entry.S Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/arch/x86/x86_64/compat/entry.S Fri Apr 06 15:07:34 2007 +0100
@@ -137,6 +137,7 @@ compat_bad_hypercall:
/* %rbx: struct vcpu, interrupts disabled */
compat_restore_all_guest:
+ ASSERT_INTERRUPTS_DISABLED
RESTORE_ALL
addq $8,%rsp
.Lft0: iretq
@@ -188,13 +189,14 @@ ENTRY(compat_post_handle_exception)
ENTRY(compat_int80_direct_trap)
call compat_create_bounce_frame
- jmp compat_restore_all_guest
+ jmp compat_test_all_events
/* CREATE A BASIC EXCEPTION FRAME ON GUEST OS (RING-1) STACK: */
/* {[ERRCODE,] EIP, CS, EFLAGS, [ESP, SS]} */
/* %rdx: trap_bounce, %rbx: struct vcpu */
/* On return only %rbx is guaranteed non-clobbered. */
compat_create_bounce_frame:
+ ASSERT_INTERRUPTS_ENABLED
mov %fs,%edi
testb $2,UREGS_cs+8(%rsp)
jz 1f
diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_64/entry.S
--- a/xen/arch/x86/x86_64/entry.S Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/arch/x86/x86_64/entry.S Fri Apr 06 15:07:34 2007 +0100
@@ -38,6 +38,7 @@ 1: call create_bounce_frame
/* %rbx: struct vcpu, interrupts disabled */
restore_all_guest:
+ ASSERT_INTERRUPTS_DISABLED
RESTORE_ALL
testw $TRAP_syscall,4(%rsp)
jz iret_exit_to_guest
@@ -230,7 +231,7 @@ ENTRY(int80_direct_trap)
/* Check that the callback is non-null. */
leaq VCPU_int80_bounce(%rbx),%rdx
- cmp $0, TRAPBOUNCE_flags(%rdx)
+ cmp $0,TRAPBOUNCE_flags(%rdx)
jz int80_slow_path
movq VCPU_domain(%rbx),%rax
@@ -238,7 +239,7 @@ ENTRY(int80_direct_trap)
jnz compat_int80_direct_trap
call create_bounce_frame
- jmp restore_all_guest
+ jmp test_all_events
int80_slow_path:
/*
@@ -256,6 +257,7 @@ int80_slow_path:
/* %rdx: trap_bounce, %rbx: struct vcpu */
/* On return only %rbx is guaranteed non-clobbered. */
create_bounce_frame:
+ ASSERT_INTERRUPTS_ENABLED
testb $TF_kernel_mode,VCPU_thread_flags(%rbx)
jnz 1f
/* Push new frame at registered guest-OS stack base. */
diff -r bd73cb523111 -r f80a97d26276 xen/arch/x86/x86_64/traps.c
--- a/xen/arch/x86/x86_64/traps.c Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/arch/x86/x86_64/traps.c Fri Apr 06 15:07:34 2007 +0100
@@ -170,7 +170,8 @@ asmlinkage void do_double_fault(struct c
regs->r9, regs->r10, regs->r11);
printk("r12: %016lx r13: %016lx r14: %016lx\n",
regs->r12, regs->r13, regs->r14);
- printk("r15: %016lx\n", regs->r15);
+ printk("r15: %016lx cs: %016lx ss: %016lx\n",
+ regs->r15, (long)regs->cs, (long)regs->ss);
show_stack_overflow(cpu, regs->rsp);
panic("DOUBLE FAULT -- system shutdown\n");
@@ -260,11 +261,14 @@ void __init percpu_traps_init(void)
idt_table[TRAP_double_fault].a |= 1UL << 32; /* IST1 */
idt_table[TRAP_nmi].a |= 2UL << 32; /* IST2 */
-#ifdef CONFIG_COMPAT
- /* The hypercall entry vector is only accessible from ring 1. */
+ /*
+ * The 32-on-64 hypercall entry vector is only accessible from ring 1.
+ * Also note that this is a trap gate, not an interrupt gate.
+ */
_set_gate(idt_table+HYPERCALL_VECTOR, 15, 1, &compat_hypercall);
+
+ /* Fast trap for int80 (faster than taking the #GP-fixup path). */
_set_gate(idt_table+0x80, 15, 3, &int80_direct_trap);
-#endif
}
stack_bottom = (char *)get_stack_bottom();
diff -r bd73cb523111 -r f80a97d26276 xen/include/asm-x86/desc.h
--- a/xen/include/asm-x86/desc.h Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/include/asm-x86/desc.h Fri Apr 06 15:07:34 2007 +0100
@@ -106,7 +106,7 @@
((((sel)>>3) < FIRST_RESERVED_GDT_ENTRY) || /* Guest seg? */ \
((sel) == (!IS_COMPAT(d) ? \
FLAT_KERNEL_CS : /* Xen default seg? */ \
- FLAT_COMPAT_KERNEL_CS)) || /* Xen default compat seg? */
\
+ FLAT_COMPAT_KERNEL_CS)) || \
((sel) & 4)) /* LDT seg? */
#endif /* __ASSEMBLY__ */
diff -r bd73cb523111 -r f80a97d26276 xen/include/asm-x86/x86_32/asm_defns.h
--- a/xen/include/asm-x86/x86_32/asm_defns.h Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/include/asm-x86/x86_32/asm_defns.h Fri Apr 06 15:07:34 2007 +0100
@@ -8,9 +8,19 @@
#define SETUP_EXCEPTION_FRAME_POINTER \
movl %esp,%ebp; \
notl %ebp
+#define ASSERT_INTERRUPT_STATUS(x) \
+ pushf; \
+ testb $X86_EFLAGS_IF>>8,1(%esp); \
+ j##x 1f; \
+ ud2a; \
+1: addl $4,%esp;
#else
#define SETUP_EXCEPTION_FRAME_POINTER
+#define ASSERT_INTERRUPT_STATUS(x)
#endif
+
+#define ASSERT_INTERRUPTS_ENABLED ASSERT_INTERRUPT_STATUS(nz)
+#define ASSERT_INTERRUPTS_DISABLED ASSERT_INTERRUPT_STATUS(z)
#define __SAVE_ALL_PRE \
cld; \
diff -r bd73cb523111 -r f80a97d26276 xen/include/asm-x86/x86_64/asm_defns.h
--- a/xen/include/asm-x86/x86_64/asm_defns.h Fri Apr 06 14:35:25 2007 +0100
+++ b/xen/include/asm-x86/x86_64/asm_defns.h Fri Apr 06 15:07:34 2007 +0100
@@ -8,9 +8,19 @@
#define SETUP_EXCEPTION_FRAME_POINTER \
movq %rsp,%rbp; \
notq %rbp
+#define ASSERT_INTERRUPT_STATUS(x) \
+ pushf; \
+ testb $X86_EFLAGS_IF>>8,1(%rsp); \
+ j##x 1f; \
+ ud2a; \
+1: addq $8,%rsp;
#else
#define SETUP_EXCEPTION_FRAME_POINTER
+#define ASSERT_INTERRUPT_STATUS(x)
#endif
+
+#define ASSERT_INTERRUPTS_ENABLED ASSERT_INTERRUPT_STATUS(nz)
+#define ASSERT_INTERRUPTS_DISABLED ASSERT_INTERRUPT_STATUS(z)
#define SAVE_ALL \
cld; \
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