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Commit 2996fca0 authored by Jan Kiszka's avatar Jan Kiszka Committed by Paolo Bonzini
Browse files

KVM: nVMX: Allow to disable VM_{ENTRY_LOAD,EXIT_SAVE}_DEBUG_CONTROLS 



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: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 560b7ee1

arch/x86/kvm/vmx.c

+38 −6
Original line number Diff line number Diff line
@@ -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 vmcs01_debugctl;

};



#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);



	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.vmcs01_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.vmcs01_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)