From 1e470be5a10801cb1c5c145f2cd9e0f5ebaf4f2e Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 18 Mar 2010 15:20:11 +0200 Subject: [PATCH] KVM: x86 emulator: fix mov dr to inject #UD when needed. If CR4.DE=1 access to registers DR4/DR5 cause #UD. Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 836e97ba45da..5afddcfa1a7e 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -2531,9 +2531,12 @@ twobyte_insn: c->dst.type = OP_NONE; /* no writeback */ break; case 0x21: /* mov from dr to reg */ - if (emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm])) - goto cannot_emulate; - rc = X86EMUL_CONTINUE; + if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && + (c->modrm_reg == 4 || c->modrm_reg == 5)) { + kvm_queue_exception(ctxt->vcpu, UD_VECTOR); + goto done; + } + emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]); c->dst.type = OP_NONE; /* no writeback */ break; case 0x22: /* mov reg, cr */ @@ -2541,9 +2544,12 @@ twobyte_insn: c->dst.type = OP_NONE; break; case 0x23: /* mov from reg to dr */ - if (emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm])) - goto cannot_emulate; - rc = X86EMUL_CONTINUE; + if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && + (c->modrm_reg == 4 || c->modrm_reg == 5)) { + kvm_queue_exception(ctxt->vcpu, UD_VECTOR); + goto done; + } + emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]); c->dst.type = OP_NONE; /* no writeback */ break; case 0x30: -- 2.20.1