From ab8557b2b361c8bb2e2421c791c8f6c4f6ba3d08 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 18 Mar 2010 15:20:09 +0200 Subject: [PATCH] KVM: x86 emulator: 0f (20|21|22|23) ignore mod bits. Resent spec says that for 0f (20|21|22|23) the 2 bits in the mod field are ignored. Interestingly enough older spec says that 11 is only valid encoding. Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 7c7debb424df..fa4604e03250 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2520,28 +2520,20 @@ twobyte_insn: c->dst.type = OP_NONE; break; case 0x20: /* mov cr, reg */ - if (c->modrm_mod != 3) - goto cannot_emulate; c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu); c->dst.type = OP_NONE; /* no writeback */ break; case 0x21: /* mov from dr to reg */ - if (c->modrm_mod != 3) - goto cannot_emulate; if (emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm])) goto cannot_emulate; rc = X86EMUL_CONTINUE; c->dst.type = OP_NONE; /* no writeback */ break; case 0x22: /* mov reg, cr */ - if (c->modrm_mod != 3) - goto cannot_emulate; ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu); c->dst.type = OP_NONE; break; case 0x23: /* mov from reg to dr */ - if (c->modrm_mod != 3) - goto cannot_emulate; if (emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm])) goto cannot_emulate; rc = X86EMUL_CONTINUE; -- 2.20.1