From 138ac8d88f91e2a6a278aa5cee9120c714c4ce2d Mon Sep 17 00:00:00 2001 From: Jan Kiszka Date: Wed, 20 Jan 2010 18:20:20 +0100 Subject: [PATCH] KVM: VMX: Fix emulation of DR4 and DR5 Make sure DR4 and DR5 are aliased to DR6 and DR7, respectively, if CR4.DE is not set. Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9727773f24b7..c7b99e1f8aae 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3039,6 +3039,15 @@ static int handle_cr(struct kvm_vcpu *vcpu) return 0; } +static int check_dr_alias(struct kvm_vcpu *vcpu) +{ + if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) { + kvm_queue_exception(vcpu, UD_VECTOR); + return -1; + } + return 0; +} + static int handle_dr(struct kvm_vcpu *vcpu) { unsigned long exit_qualification; @@ -3081,14 +3090,20 @@ static int handle_dr(struct kvm_vcpu *vcpu) case 0 ... 3: val = vcpu->arch.db[dr]; break; + case 4: + if (check_dr_alias(vcpu) < 0) + return 1; + /* fall through */ case 6: val = vcpu->arch.dr6; break; - case 7: + case 5: + if (check_dr_alias(vcpu) < 0) + return 1; + /* fall through */ + default: /* 7 */ val = vcpu->arch.dr7; break; - default: - val = 0; } kvm_register_write(vcpu, reg, val); } else { @@ -3099,12 +3114,10 @@ static int handle_dr(struct kvm_vcpu *vcpu) if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) vcpu->arch.eff_db[dr] = val; break; - case 4 ... 5: - if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) { - kvm_queue_exception(vcpu, UD_VECTOR); + case 4: + if (check_dr_alias(vcpu) < 0) return 1; - } - break; + /* fall through */ case 6: if (val & 0xffffffff00000000ULL) { kvm_inject_gp(vcpu, 0); @@ -3112,7 +3125,11 @@ static int handle_dr(struct kvm_vcpu *vcpu) } vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1; break; - case 7: + case 5: + if (check_dr_alias(vcpu) < 0) + return 1; + /* fall through */ + default: /* 7 */ if (val & 0xffffffff00000000ULL) { kvm_inject_gp(vcpu, 0); return 1;