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Date:   Fri, 28 Apr 2023 19:17:33 +0000
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Subject: Re: [PATCH v13 098/113] KVM: TDX: Handle TDX PV map_gpa hypercall
From:   Ryan Afranji <afranji@google.com>
To:     isaku.yamahata@intel.com
Cc:     dmatlack@google.com, erdemaktas@google.com,
        isaku.yamahata@gmail.com, kai.huang@intel.com, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, pbonzini@redhat.com,
        sagis@google.com, seanjc@google.com, zhi.wang.linux@gmail.com
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Precedence: bulk

+static int tdx_map_gpa(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = vcpu->kvm;
+	gpa_t gpa = tdvmcall_a0_read(vcpu);
+	gpa_t size = tdvmcall_a1_read(vcpu);
+	gpa_t end = gpa + size;
+
+	if (!IS_ALIGNED(gpa, PAGE_SIZE) || !IS_ALIGNED(size, PAGE_SIZE) ||
+	    end < gpa ||
+	    end > kvm_gfn_shared_mask(kvm) << (PAGE_SHIFT + 1) ||
+	    kvm_is_private_gpa(kvm, gpa) != kvm_is_private_gpa(kvm, end)) {
+		tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND);

According to table 3-6 of the GHCI spec, TDG.VP.VMCALL_ALIGN_ERROR should be
returned if there is an alignment error for the size or start GPA. Right now,
TDG_VP_VMCALL_INVALID_OPERAND is being returned instead. Can this be updated?

+		return 1;
+	}
+
+	return tdx_vp_vmcall_to_user(vcpu);
+}
+