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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>, erdemaktas@google.com,
        Sean Christopherson <seanjc@google.com>,
        Sagi Shahar <sagis@google.com>,
        David Matlack <dmatlack@google.com>
Subject: [PATCH v11 039/113] KVM: x86/mmu: Require TDP MMU for TDX
Date:   Thu, 12 Jan 2023 08:31:47 -0800
Message-Id: <c67b3702c8721d4164eaf5f56474747aeeefd426.1673539699.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

Require the TDP MMU for guest TDs, the so called "shadow" MMU does not
support mapping guest private memory, i.e. does not support Secure-EPT.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index fdcff390ebc2..6c3ce4121a46 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -27,6 +27,13 @@ int kvm_mmu_init_tdp_mmu(struct kvm *kvm)
 	if (kvm->arch.vm_type == KVM_X86_TDX_VM && !enable_mmio_caching)
 		return -EOPNOTSUPP;
 
+	/*
+	 * Because only the TDP MMU supports TDX, require the TDP MMU for guest
+	 * TDs.
+	 */
+	if (kvm->arch.vm_type == KVM_X86_TDX_VM && !tdp_enabled)
+		return -EOPNOTSUPP;
+
 	if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled))
 		return 0;
 
-- 
2.25.1