We change the x86_emulate_insn() to handle faults propagated from kvm_load_segment_descriptor().
Original code checks if the return value is negative or not. But this means nothing because kvm_load_segment_descriptor() never returns negative value. Instead of this, we use the rc variable to hold the return value and if it is not X86EMUL_CONTINUE goto done, not cannot_emulate. Be sure that those codes following done label checks rc is X86EMUL_UNHANDLEABLE or not, and if it is so do the same thing as cannot_emulate: only the FAULT case will change. Signed-off-by: Takuya Yoshikawa <[email protected]> --- arch/x86/kvm/emulate.c | 18 ++++++++---------- 1 files changed, 8 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 645b245..4527940 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1980,7 +1980,6 @@ special_insn: case 0x8e: { /* mov seg, r/m16 */ uint16_t sel; int type_bits; - int err; sel = c->src.val; if (c->modrm_reg == VCPU_SREG_SS) @@ -1988,16 +1987,16 @@ special_insn: if (c->modrm_reg <= 5) { type_bits = (c->modrm_reg == 1) ? 9 : 1; - err = kvm_load_segment_descriptor(ctxt->vcpu, sel, - type_bits, c->modrm_reg); + rc = kvm_load_segment_descriptor(ctxt->vcpu, sel, + type_bits, c->modrm_reg); } else { printk(KERN_INFO "Invalid segreg in modrm byte 0x%02x\n", c->modrm); goto cannot_emulate; } - if (err < 0) - goto cannot_emulate; + if (rc != X86EMUL_CONTINUE) + goto done; c->dst.type = OP_NONE; /* Disable writeback. */ break; @@ -2168,11 +2167,10 @@ special_insn: case 0xe9: /* jmp rel */ goto jmp; case 0xea: /* jmp far */ - if (kvm_load_segment_descriptor(ctxt->vcpu, c->src2.val, 9, - VCPU_SREG_CS) < 0) { - DPRINTF("jmp far: Failed to load CS descriptor\n"); - goto cannot_emulate; - } + rc = kvm_load_segment_descriptor(ctxt->vcpu, c->src2.val, 9, + VCPU_SREG_CS); + if (rc != X86EMUL_CONTINUE) + goto done; c->eip = c->src.val; break; -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
