From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 4/5] KVM: nVMX: Allow to disable VM_{ENTRY_LOAD,EXIT_SAVE}_DEBUG_CONTROLS Date: Mon, 16 Jun 2014 12:43:05 +0200 Message-ID: <539ECA39.3010305@redhat.com> References: <14e79bd0cdaf74b331d260c1aae68f1841df4944.1402841929.git.jan.kiszka@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm , Bandan Das To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60315 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754997AbaFPKnK (ORCPT ); Mon, 16 Jun 2014 06:43:10 -0400 In-Reply-To: <14e79bd0cdaf74b331d260c1aae68f1841df4944.1402841929.git.jan.kiszka@web.de> Sender: kvm-owner@vger.kernel.org List-ID: Il 15/06/2014 16:18, Jan Kiszka ha scritto: > From: Jan Kiszka > > Allow L1 to "leak" its debug controls into L2, i.e. permit cleared > VM_{ENTRY_LOAD,EXIT_SAVE}_DEBUG_CONTROLS. This requires to manually > transfer the state of DR7 and IA32_DEBUGCTLMSR from L1 into L2 as both > run on different VMCS. > > Signed-off-by: Jan Kiszka > --- > arch/x86/kvm/vmx.c | 44 ++++++++++++++++++++++++++++++++++++++------ > 1 file changed, 38 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index 475f2dc..b31e9f1 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -383,6 +383,9 @@ struct nested_vmx { > > struct hrtimer preemption_timer; > bool preemption_timer_expired; > + > + /* to migrate it to L2 if VM_ENTRY_LOAD_DEBUG_CONTROLS is off */ > + u64 host_debugctl; I think vmcs01_debugctl would be more descriptive of the role. What do you think? I can fix it up myself when merging the patch. Paolo > }; > > #define POSTED_INTR_ON 0 > @@ -2243,7 +2246,9 @@ static u32 nested_vmx_true_procbased_ctls_low; > static u32 nested_vmx_secondary_ctls_low, nested_vmx_secondary_ctls_high; > static u32 nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high; > static u32 nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high; > +static u32 nested_vmx_true_exit_ctls_low; > static u32 nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high; > +static u32 nested_vmx_true_entry_ctls_low; > static u32 nested_vmx_misc_low, nested_vmx_misc_high; > static u32 nested_vmx_ept_caps; > static __init void nested_vmx_setup_ctls_msrs(void) > @@ -2289,6 +2294,10 @@ static __init void nested_vmx_setup_ctls_msrs(void) > if (vmx_mpx_supported()) > nested_vmx_exit_ctls_high |= VM_EXIT_CLEAR_BNDCFGS; > > + /* We support free control of debug control saving. */ > + nested_vmx_true_exit_ctls_low = nested_vmx_exit_ctls_low & > + ~VM_EXIT_SAVE_DEBUG_CONTROLS; > + > /* entry controls */ > rdmsr(MSR_IA32_VMX_ENTRY_CTLS, > nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high); > @@ -2303,6 +2312,10 @@ static __init void nested_vmx_setup_ctls_msrs(void) > if (vmx_mpx_supported()) > nested_vmx_entry_ctls_high |= VM_ENTRY_LOAD_BNDCFGS; > > + /* We support free control of debug control loading. */ > + nested_vmx_true_entry_ctls_low = nested_vmx_entry_ctls_low & > + ~VM_ENTRY_LOAD_DEBUG_CONTROLS; > + > /* cpu-based controls */ > rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, > nested_vmx_procbased_ctls_low, nested_vmx_procbased_ctls_high); > @@ -2409,11 +2422,17 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) > nested_vmx_procbased_ctls_high); > break; > case MSR_IA32_VMX_TRUE_EXIT_CTLS: > + *pdata = vmx_control_msr(nested_vmx_true_exit_ctls_low, > + nested_vmx_exit_ctls_high); > + break; > case MSR_IA32_VMX_EXIT_CTLS: > *pdata = vmx_control_msr(nested_vmx_exit_ctls_low, > nested_vmx_exit_ctls_high); > break; > case MSR_IA32_VMX_TRUE_ENTRY_CTLS: > + *pdata = vmx_control_msr(nested_vmx_true_entry_ctls_low, > + nested_vmx_entry_ctls_high); > + break; > case MSR_IA32_VMX_ENTRY_CTLS: > *pdata = vmx_control_msr(nested_vmx_entry_ctls_low, > nested_vmx_entry_ctls_high); > @@ -7836,7 +7855,13 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) > vmcs_writel(GUEST_GDTR_BASE, vmcs12->guest_gdtr_base); > vmcs_writel(GUEST_IDTR_BASE, vmcs12->guest_idtr_base); > > - vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl); > + if (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS) { > + kvm_set_dr(vcpu, 7, vmcs12->guest_dr7); > + vmcs_write64(GUEST_IA32_DEBUGCTL, vmcs12->guest_ia32_debugctl); > + } else { > + kvm_set_dr(vcpu, 7, vcpu->arch.dr7); > + vmcs_write64(GUEST_IA32_DEBUGCTL, vmx->nested.host_debugctl); > + } > vmcs_write32(VM_ENTRY_INTR_INFO_FIELD, > vmcs12->vm_entry_intr_info_field); > vmcs_write32(VM_ENTRY_EXCEPTION_ERROR_CODE, > @@ -7846,7 +7871,6 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) > vmcs_write32(GUEST_INTERRUPTIBILITY_INFO, > vmcs12->guest_interruptibility_info); > vmcs_write32(GUEST_SYSENTER_CS, vmcs12->guest_sysenter_cs); > - kvm_set_dr(vcpu, 7, vmcs12->guest_dr7); > vmx_set_rflags(vcpu, vmcs12->guest_rflags); > vmcs_writel(GUEST_PENDING_DBG_EXCEPTIONS, > vmcs12->guest_pending_dbg_exceptions); > @@ -8143,9 +8167,11 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) > !vmx_control_verify(vmcs12->pin_based_vm_exec_control, > nested_vmx_pinbased_ctls_low, nested_vmx_pinbased_ctls_high) || > !vmx_control_verify(vmcs12->vm_exit_controls, > - nested_vmx_exit_ctls_low, nested_vmx_exit_ctls_high) || > + nested_vmx_true_exit_ctls_low, > + nested_vmx_exit_ctls_high) || > !vmx_control_verify(vmcs12->vm_entry_controls, > - nested_vmx_entry_ctls_low, nested_vmx_entry_ctls_high)) > + nested_vmx_true_entry_ctls_low, > + nested_vmx_entry_ctls_high)) > { > nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); > return 1; > @@ -8222,6 +8248,9 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) > > vmx->nested.vmcs01_tsc_offset = vmcs_read64(TSC_OFFSET); > > + if (!(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_DEBUG_CONTROLS)) > + vmx->nested.host_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); > + > cpu = get_cpu(); > vmx->loaded_vmcs = vmcs02; > vmx_vcpu_put(vcpu); > @@ -8399,7 +8428,6 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, > vmcs12->guest_cr0 = vmcs12_guest_cr0(vcpu, vmcs12); > vmcs12->guest_cr4 = vmcs12_guest_cr4(vcpu, vmcs12); > > - kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7); > vmcs12->guest_rsp = kvm_register_read(vcpu, VCPU_REGS_RSP); > vmcs12->guest_rip = kvm_register_read(vcpu, VCPU_REGS_RIP); > vmcs12->guest_rflags = vmcs_readl(GUEST_RFLAGS); > @@ -8478,9 +8506,13 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, > (vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) | > (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE); > > + if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS) { > + kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7); > + vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); > + } > + > /* TODO: These cannot have changed unless we have MSR bitmaps and > * the relevant bit asks not to trap the change */ > - vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL); > if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_PAT) > vmcs12->guest_ia32_pat = vmcs_read64(GUEST_IA32_PAT); > if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER) >