diff options
Diffstat (limited to 'drivers/lguest/interrupts_and_traps.c')
| -rw-r--r-- | drivers/lguest/interrupts_and_traps.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/lguest/interrupts_and_traps.c b/drivers/lguest/interrupts_and_traps.c index daaf8663164..70dfcdc29f1 100644 --- a/drivers/lguest/interrupts_and_traps.c +++ b/drivers/lguest/interrupts_and_traps.c @@ -140,6 +140,16 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, cpu->regs->eip = idt_address(lo, hi); /* + * Trapping always clears these flags: + * TF: Trap flag + * VM: Virtual 8086 mode + * RF: Resume + * NT: Nested task. + */ + cpu->regs->eflags &= + ~(X86_EFLAGS_TF|X86_EFLAGS_VM|X86_EFLAGS_RF|X86_EFLAGS_NT); + + /* * There are two kinds of interrupt handlers: 0xE is an "interrupt * gate" which expects interrupts to be disabled on entry. */ @@ -375,11 +385,9 @@ static bool direct_trap(unsigned int num) /* * The Host needs to see page faults (for shadow paging and to save the * fault address), general protection faults (in/out emulation) and - * device not available (TS handling), invalid opcode fault (kvm hcall), - * and of course, the hypercall trap. + * device not available (TS handling) and of course, the hypercall trap. */ - return num != 14 && num != 13 && num != 7 && - num != 6 && num != LGUEST_TRAP_ENTRY; + return num != 14 && num != 13 && num != 7 && num != LGUEST_TRAP_ENTRY; } /*:*/ @@ -429,8 +437,8 @@ void pin_stack_pages(struct lg_cpu *cpu) /* * Direct traps also mean that we need to know whenever the Guest wants to use - * a different kernel stack, so we can change the IDT entries to use that - * stack. The IDT entries expect a virtual address, so unlike most addresses + * a different kernel stack, so we can change the guest TSS to use that + * stack. The TSS entries expect a virtual address, so unlike most addresses * the Guest gives us, the "esp" (stack pointer) value here is virtual, not * physical. * |