From 6e154e56b4d7a6a28c54f0984e13d3f8defc4755 Mon Sep 17 00:00:00 2001 From: Mohammed Gamal Date: Wed, 4 Aug 2010 14:38:06 +0300 Subject: [PATCH] KVM: x86 emulator: Add into, int, and int3 instructions (opcodes 0xcc-0xce) This adds support for int instructions to the emulator. Signed-off-by: Mohammed Gamal Signed-off-by: Avi Kivity --- arch/x86/kvm/emulate.c | 78 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index a9a4a0b78a7d..5205d6890828 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1180,6 +1180,67 @@ static int emulate_popa(struct x86_emulate_ctxt *ctxt, return rc; } +int emulate_int_real(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, int irq) +{ + struct decode_cache *c = &ctxt->decode; + int rc = X86EMUL_CONTINUE; + struct desc_ptr dt; + gva_t cs_addr; + gva_t eip_addr; + u16 cs, eip; + u32 err; + + /* TODO: Add limit checks */ + c->src.val = ctxt->eflags; + emulate_push(ctxt, ops); + + ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC); + + c->src.val = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu); + emulate_push(ctxt, ops); + + c->src.val = c->eip; + emulate_push(ctxt, ops); + + ops->get_idt(&dt, ctxt->vcpu); + + eip_addr = dt.address + (irq << 2); + cs_addr = dt.address + (irq << 2) + 2; + + rc = ops->read_std(cs_addr, &cs, 2, ctxt->vcpu, &err); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = ops->read_std(eip_addr, &eip, 2, ctxt->vcpu, &err); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = load_segment_descriptor(ctxt, ops, cs, VCPU_SREG_CS); + if (rc != X86EMUL_CONTINUE) + return rc; + + c->eip = eip; + + return rc; +} + +static int emulate_int(struct x86_emulate_ctxt *ctxt, + struct x86_emulate_ops *ops, int irq) +{ + switch(ctxt->mode) { + case X86EMUL_MODE_REAL: + return emulate_int_real(ctxt, ops, irq); + case X86EMUL_MODE_VM86: + case X86EMUL_MODE_PROT16: + case X86EMUL_MODE_PROT32: + case X86EMUL_MODE_PROT64: + default: + /* Protected mode interrupts unimplemented yet */ + return X86EMUL_UNHANDLEABLE; + } +} + static int emulate_iret_real(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { @@ -2616,6 +2677,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt) struct decode_cache *c = &ctxt->decode; int rc = X86EMUL_CONTINUE; int saved_dst_type = c->dst.type; + int irq; /* Used for int 3, int, and into */ ctxt->decode.mem_read.pos = 0; @@ -2960,6 +3022,22 @@ special_insn: if (rc != X86EMUL_CONTINUE) goto done; break; + case 0xcc: /* int3 */ + irq = 3; + goto do_interrupt; + case 0xcd: /* int n */ + irq = c->src.val; + do_interrupt: + rc = emulate_int(ctxt, ops, irq); + if (rc != X86EMUL_CONTINUE) + goto done; + break; + case 0xce: /* into */ + if (ctxt->eflags & EFLG_OF) { + irq = 4; + goto do_interrupt; + } + break; case 0xcf: /* iret */ rc = emulate_iret(ctxt, ops); -- 2.30.2