diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_x86_emulate.h | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 | ||||
| -rw-r--r-- | arch/x86/kvm/x86_emulate.c | 20 |
3 files changed, 28 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_x86_emulate.h b/arch/x86/include/asm/kvm_x86_emulate.h index be40d6e2b6b..b7ed2c42311 100644 --- a/arch/x86/include/asm/kvm_x86_emulate.h +++ b/arch/x86/include/asm/kvm_x86_emulate.h @@ -155,6 +155,9 @@ struct x86_emulate_ctxt { int mode; u32 cs_base; + /* interruptibility state, as a result of execution of STI or MOV SS */ + int interruptibility; + /* decode cache */ struct decode_cache decode; }; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 7475b029b2a..48f744ff0bc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2379,7 +2379,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu, u16 error_code, int emulation_type) { - int r; + int r, shadow_mask; struct decode_cache *c; kvm_clear_exception_queue(vcpu); @@ -2433,6 +2433,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu, } r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops); + shadow_mask = vcpu->arch.emulate_ctxt.interruptibility; + + if (r == 0) + kvm_x86_ops->set_interrupt_shadow(vcpu, shadow_mask); if (vcpu->arch.pio.string) return EMULATE_DO_MMIO; diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c index d2664fcba7f..c1b6c232e02 100644 --- a/arch/x86/kvm/x86_emulate.c +++ b/arch/x86/kvm/x86_emulate.c @@ -1361,6 +1361,20 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt, return 0; } +void toggle_interruptibility(struct x86_emulate_ctxt *ctxt, u32 mask) +{ + u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(ctxt->vcpu, mask); + /* + * an sti; sti; sequence only disable interrupts for the first + * instruction. So, if the last instruction, be it emulated or + * not, left the system with the INT_STI flag enabled, it + * means that the last instruction is an sti. We should not + * leave the flag on in this case. The same goes for mov ss + */ + if (!(int_shadow & mask)) + ctxt->interruptibility = mask; +} + int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { @@ -1372,6 +1386,8 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) int io_dir_in; int rc = 0; + ctxt->interruptibility = 0; + /* Shadow copy of register state. Committed on successful emulation. * NOTE: we can copy them from vcpu as x86_decode_insn() doesn't * modify them. @@ -1618,6 +1634,9 @@ special_insn: int err; sel = c->src.val; + if (c->modrm_reg == VCPU_SREG_SS) + toggle_interruptibility(ctxt, X86_SHADOW_INT_MOV_SS); + if (c->modrm_reg <= 5) { type_bits = (c->modrm_reg == 1) ? 9 : 1; err = kvm_load_segment_descriptor(ctxt->vcpu, sel, @@ -1847,6 +1866,7 @@ special_insn: c->dst.type = OP_NONE; /* Disable writeback. */ break; case 0xfb: /* sti */ + toggle_interruptibility(ctxt, X86_SHADOW_INT_STI); ctxt->eflags |= X86_EFLAGS_IF; c->dst.type = OP_NONE; /* Disable writeback. */ break; |