linux-kernel - [PATCH v6 21/33] KVM: VMX: Tweak the special handling of SECONDARY_EXEC_ENCLS_EXITING in setup_vmcs

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Message-Id: <20220830133737.1539624-22-vkuznets@redhat.com>
Date:   Tue, 30 Aug 2022 15:37:25 +0200
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <seanjc@...gle.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Michael Kelley <mikelley@...rosoft.com>,
        Yuan Yao <yuan.yao@...ux.intel.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        linux-hyperv@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v6 21/33] KVM: VMX: Tweak the special handling of SECONDARY_EXEC_ENCLS_EXITING in setup_vmcs_config()

SECONDARY_EXEC_ENCLS_EXITING is the only control which is conditionally
added to the 'optional' checklist in setup_vmcs_config() but the special
case can be avoided by always checking for its presence first and filtering
out the result later.

Note: the situation when SECONDARY_EXEC_ENCLS_EXITING is present but
cpu_has_sgx() is false is possible when SGX is "soft-disabled", e.g. if
software writes MCE control MSRs or there's an uncorrectable #MC.

Reviewed-by: Jim Mattson <jmattson@...gle.com>
Reviewed-by: Maxim Levitsky <mlevitsk@...hat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/kvm/vmx/vmx.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cfe1a1157302..9a9cdd4ea34d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2605,9 +2605,9 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 			SECONDARY_EXEC_PT_CONCEAL_VMX |
 			SECONDARY_EXEC_ENABLE_VMFUNC |
 			SECONDARY_EXEC_BUS_LOCK_DETECTION |
-			SECONDARY_EXEC_NOTIFY_VM_EXITING;
-		if (cpu_has_sgx())
-			opt2 |= SECONDARY_EXEC_ENCLS_EXITING;
+			SECONDARY_EXEC_NOTIFY_VM_EXITING |
+			SECONDARY_EXEC_ENCLS_EXITING;
+
 		if (adjust_vmx_controls(min2, opt2,
 					MSR_IA32_VMX_PROCBASED_CTLS2,
 					&_cpu_based_2nd_exec_control) < 0)
@@ -2654,6 +2654,9 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 		vmx_cap->vpid = 0;
 	}
 
+	if (!cpu_has_sgx())
+		_cpu_based_2nd_exec_control &= ~SECONDARY_EXEC_ENCLS_EXITING;
+
 	if (_cpu_based_exec_control & CPU_BASED_ACTIVATE_TERTIARY_CONTROLS) {
 		u64 opt3 = TERTIARY_EXEC_IPI_VIRT;
 
-- 
2.37.2