linux-kernel - [PATCH v2 7/7] KVM: nVMX: Drop unnecessary check on ept caps for execute-only

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Date:   Fri,  7 Feb 2020 09:37:47 -0800
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Paolo Bonzini <pbonzini@...hat.com>
Cc:     Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 7/7] KVM: nVMX: Drop unnecessary check on ept caps for execute-only

Drop the call to cpu_has_vmx_ept_execute_only() when calculating which
EPT capabilities will be exposed to L1 for nested EPT.  The resulting
configuration is immediately sanitized by the passed in @ept_caps, and
except for the call from vmx_check_processor_compat(), @ept_caps is the
capabilities that are queried by cpu_has_vmx_ept_execute_only().  For
vmx_check_processor_compat(), KVM *wants* to ignore vmx_capability.ept
so that a divergence in EPT capabilities between CPUs is detected.

Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
 arch/x86/kvm/vmx/nested.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 2d7b87b532f5..fe7da5e2fc59 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6071,10 +6071,9 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps,
 			VMX_EPT_PAGE_WALK_4_BIT |
 			VMX_EPT_PAGE_WALK_5_BIT |
 			VMX_EPTP_WB_BIT |
-			VMX_EPT_INVEPT_BIT;
-		if (cpu_has_vmx_ept_execute_only())
-			msrs->ept_caps |=
-				VMX_EPT_EXECUTE_ONLY_BIT;
+			VMX_EPT_INVEPT_BIT |
+			VMX_EPT_EXECUTE_ONLY_BIT;
+
 		msrs->ept_caps &= ept_caps;
 		msrs->ept_caps |= VMX_EPT_EXTENT_GLOBAL_BIT |
 			VMX_EPT_EXTENT_CONTEXT_BIT | VMX_EPT_2MB_PAGE_BIT |
-- 
2.24.1