KVM: VMX: Inject #GP, not #UD, if SGX2 ENCLS leafs are unsupported

Per Intel's SDM, unsupported ENCLS leafs result in a #GP, not a #UD. SGX1 is a special snowflake as the SGX1 flag is used by the CPU as a "soft" disable, e.g. if software disables machine check reporting, i.e. having SGX but not SGX1 is effectively "SGX completely unsupported" and and thus #UDs. Fixes: 9798adb ("KVM: VMX: Frame in ENCLS handler for SGX virtualization") Cc: Binbin Wu <[email protected]> Cc: Kai Huang <[email protected]> Tested-by: Kai Huang <[email protected]> Reviewed-by: Kai Huang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sean Christopherson <[email protected]>
Kleist · Jun 2, 2023 · c3a1e11 · c3a1e11
1 parent 5e50082
commit c3a1e11
Showing 1 changed file with 9 additions and 6 deletions.
diff --git a/arch/x86/kvm/vmx/sgx.c b/arch/x86/kvm/vmx/sgx.c
@@ -357,11 +357,12 @@ static int handle_encls_einit(struct kvm_vcpu *vcpu)
 
 static inline bool encls_leaf_enabled_in_guest(struct kvm_vcpu *vcpu, u32 leaf)
 {
-	if (!enable_sgx || !guest_cpuid_has(vcpu, X86_FEATURE_SGX))
-		return false;
-
+	/*
+	 * ENCLS generates a #UD if SGX1 isn't supported, i.e. this point will
+	 * be reached if and only if the SGX1 leafs are enabled.
+	 */
 	if (leaf >= ECREATE && leaf <= ETRACK)
-		return guest_cpuid_has(vcpu, X86_FEATURE_SGX1);
+		return true;
 
 	if (leaf >= EAUG && leaf <= EMODT)
 		return guest_cpuid_has(vcpu, X86_FEATURE_SGX2);
@@ -380,9 +381,11 @@ int handle_encls(struct kvm_vcpu *vcpu)
 {
 	u32 leaf = (u32)kvm_rax_read(vcpu);
 
-	if (!encls_leaf_enabled_in_guest(vcpu, leaf)) {
+	if (!enable_sgx || !guest_cpuid_has(vcpu, X86_FEATURE_SGX) ||
+	    !guest_cpuid_has(vcpu, X86_FEATURE_SGX1)) {
 		kvm_queue_exception(vcpu, UD_VECTOR);
-	} else if (!sgx_enabled_in_guest_bios(vcpu) || !is_paging(vcpu)) {
+	} else if (!encls_leaf_enabled_in_guest(vcpu, leaf) ||
+		   !sgx_enabled_in_guest_bios(vcpu) || !is_paging(vcpu)) {
 		kvm_inject_gp(vcpu, 0);
 	} else {
 		if (leaf == ECREATE)