Il 27/12/2013 19:17, Jan Kiszka ha scritto: > > From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > > In contrast to VMX, SVM dose not automatically transfer DR6 into the > VCPU's arch.dr6. So if we face a DR6 read, we must consult a new vendor > hook to obtain the current value. And as SVM now picks the DR6 state > from its VMCB, we also need a set callback in order to write updates of > DR6 back. > > Fixes a regression of 020df0794f. > > Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > --- > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/svm.c | 18 ++++++++++++++++++ > arch/x86/kvm/vmx.c | 11 +++++++++++ > arch/x86/kvm/x86.c | 3 ++- > 4 files changed, 33 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > index ae5d783..e73651b 100644 > --- a/arch/x86/include/asm/kvm_host.h > +++ b/arch/x86/include/asm/kvm_host.h > @@ -699,6 +699,8 @@ struct kvm_x86_ops { > void (*set_idt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt); > void (*get_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt); > void (*set_gdt)(struct kvm_vcpu *vcpu, struct desc_ptr *dt); > + u64 (*get_dr6)(struct kvm_vcpu *vcpu); > + void (*set_dr6)(struct kvm_vcpu *vcpu, unsigned long value); > void (*set_dr7)(struct kvm_vcpu *vcpu, unsigned long value); > void (*cache_reg)(struct kvm_vcpu *vcpu, enum kvm_reg reg); > unsigned long (*get_rflags)(struct kvm_vcpu *vcpu); > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index c7168a5..5987414 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -1671,6 +1671,22 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd) > mark_dirty(svm->vmcb, VMCB_ASID); > } > > +static u64 svm_get_dr6(struct kvm_vcpu *vcpu) > +{ > + if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) > + return vcpu->arch.dr6; > + else > + return to_svm(vcpu)->vmcb->save.dr6; > +} > + > +static void svm_set_dr6(struct kvm_vcpu *vcpu, unsigned long value) > +{ > + struct vcpu_svm *svm = to_svm(vcpu); > + > + svm->vmcb->save.dr6 = value; > + mark_dirty(svm->vmcb, VMCB_DR); The code here is a bit different from the existing DR7 hooks. Why isn't get_dr7 needed? I cannot find anything in the AMD manuals that suggests a difference between DR6 and DR7. Also, set_dr7 is only called when !(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP). I think it makes sense to do the same for all the new hooks you need to introduce (get_dr6, set_dr6 and possibly get_dr7). And finally, is it necessary to write to both vcpu->arch.dr6/7 and svm->vmcb->save.dr6/7, or is it simply okay to do that? Paolo > +} > + > static void svm_set_dr7(struct kvm_vcpu *vcpu, unsigned long value) > { > struct vcpu_svm *svm = to_svm(vcpu); > @@ -4286,6 +4302,8 @@ static struct kvm_x86_ops svm_x86_ops = { > .set_idt = svm_set_idt, > .get_gdt = svm_get_gdt, > .set_gdt = svm_set_gdt, > + .get_dr6 = svm_get_dr6, > + .set_dr6 = svm_set_dr6, > .set_dr7 = svm_set_dr7, > .cache_reg = svm_cache_reg, > .get_rflags = svm_get_rflags, > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index ee3bf54..1d9b0ec 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -5153,6 +5153,15 @@ static int handle_dr(struct kvm_vcpu *vcpu) > return 1; > } > > +static u64 vmx_get_dr6(struct kvm_vcpu *vcpu) > +{ > + return vcpu->arch.dr6; > +} > + > +static void vmx_set_dr6(struct kvm_vcpu *vcpu, unsigned long val) > +{ > +} > + > static void vmx_set_dr7(struct kvm_vcpu *vcpu, unsigned long val) > { > vmcs_writel(GUEST_DR7, val); > @@ -8573,6 +8582,8 @@ static struct kvm_x86_ops vmx_x86_ops = { > .set_idt = vmx_set_idt, > .get_gdt = vmx_get_gdt, > .set_gdt = vmx_set_gdt, > + .get_dr6 = vmx_get_dr6, > + .set_dr6 = vmx_set_dr6, > .set_dr7 = vmx_set_dr7, > .cache_reg = vmx_cache_reg, > .get_rflags = vmx_get_rflags, > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 1dc0359..be000ec 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -747,6 +747,7 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val) > if (val & 0xffffffff00000000ULL) > return -1; /* #GP */ > vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1; > + kvm_x86_ops->set_dr6(vcpu, vcpu->arch.dr6); > break; > case 5: > if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) > @@ -788,7 +789,7 @@ static int _kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val) > return 1; > /* fall through */ > case 6: > - *val = vcpu->arch.dr6; > + *val = kvm_x86_ops->get_dr6(vcpu); > break; > case 5: > if (kvm_read_cr4_bits(vcpu, X86_CR4_DE)) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html