linux-kernel - [PATCH v2 1/4] KVM: nVMX: Sanitize primary processor-based VM-execution controls with eVMCS too

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Date:   Fri,  4 Nov 2022 15:47:05 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>
Cc:     Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/4] KVM: nVMX: Sanitize primary processor-based VM-execution controls with eVMCS too

The only unsupported primary processor-based VM-execution control at the
moment is CPU_BASED_ACTIVATE_TERTIARY_CONTROLS and KVM doesn't expose it
in nested VMX feature MSRs anyway (see nested_vmx_setup_ctls_msrs())
but in preparation to inverting "unsupported with eVMCS" checks (and
for completeness) it's better to sanitize MSR_IA32_VMX_PROCBASED_CTLS/
MSR_IA32_VMX_TRUE_PROCBASED_CTLS too.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
---
 arch/x86/kvm/vmx/evmcs.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c
index d8b23c96d627..337783675731 100644
--- a/arch/x86/kvm/vmx/evmcs.c
+++ b/arch/x86/kvm/vmx/evmcs.c
@@ -368,6 +368,7 @@ enum evmcs_revision {
 enum evmcs_ctrl_type {
 	EVMCS_EXIT_CTRLS,
 	EVMCS_ENTRY_CTRLS,
+	EVMCS_EXEC_CTRL,
 	EVMCS_2NDEXEC,
 	EVMCS_PINCTRL,
 	EVMCS_VMFUNC,
@@ -381,6 +382,9 @@ static const u32 evmcs_unsupported_ctrls[NR_EVMCS_CTRLS][NR_EVMCS_REVISIONS] = {
 	[EVMCS_ENTRY_CTRLS] = {
 		[EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_VMENTRY_CTRL,
 	},
+	[EVMCS_EXEC_CTRL] = {
+		[EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_EXEC_CTRL,
+	},
 	[EVMCS_2NDEXEC] = {
 		[EVMCSv1_LEGACY] = EVMCS1_UNSUPPORTED_2NDEXEC,
 	},
@@ -441,6 +445,10 @@ void nested_evmcs_filter_control_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *
 			unsupported_ctrls |= VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
 		ctl_high &= ~unsupported_ctrls;
 		break;
+	case MSR_IA32_VMX_PROCBASED_CTLS:
+	case MSR_IA32_VMX_TRUE_PROCBASED_CTLS:
+		ctl_high &= ~evmcs_get_unsupported_ctls(EVMCS_EXEC_CTRL);
+		break;
 	case MSR_IA32_VMX_PROCBASED_CTLS2:
 		ctl_high &= ~evmcs_get_unsupported_ctls(EVMCS_2NDEXEC);
 		break;
@@ -468,6 +476,10 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
 					       vmcs12->pin_based_vm_exec_control)))
 		return -EINVAL;
 
+	if (CC(!nested_evmcs_is_valid_controls(EVMCS_EXEC_CTRL,
+					       vmcs12->cpu_based_vm_exec_control)))
+		return -EINVAL;
+
 	if (CC(!nested_evmcs_is_valid_controls(EVMCS_2NDEXEC,
 					       vmcs12->secondary_vm_exec_control)))
 		return -EINVAL;
-- 
2.38.1