1 files changed, 79 insertions, 1 deletions

diff --git a/arch/x86/kvm/vmx/sgx.c b/arch/x86/kvm/vmx/sgx.c
index 2eed5da91698..6693ebdc0770 100644
--- a/arch/x86/kvm/vmx/sgx.c
+++ b/arch/x86/kvm/vmx/sgx.c
@@ -5,11 +5,13 @@
 
 #include "cpuid.h"
 #include "kvm_cache_regs.h"
+#include "nested.h"
 #include "sgx.h"
 #include "vmx.h"
 #include "x86.h"
 
-bool __read_mostly enable_sgx;
+bool __read_mostly enable_sgx = 1;
+module_param_named(sgx, enable_sgx, bool, 0444);
 
 /* Initial value of guest's virtual SGX_LEPUBKEYHASHn MSRs */
 static u64 sgx_pubkey_hash[4] __ro_after_init;
@@ -422,3 +424,79 @@ void vcpu_setup_sgx_lepubkeyhash(struct kvm_vcpu *vcpu)
 	memcpy(vmx->msr_ia32_sgxlepubkeyhash, sgx_pubkey_hash,
 	       sizeof(sgx_pubkey_hash));
 }
+
+/*
+ * ECREATE must be intercepted to enforce MISCSELECT, ATTRIBUTES and XFRM
+ * restrictions if the guest's allowed-1 settings diverge from hardware.
+ */
+static bool sgx_intercept_encls_ecreate(struct kvm_vcpu *vcpu)
+{
+	struct kvm_cpuid_entry2 *guest_cpuid;
+	u32 eax, ebx, ecx, edx;
+
+	if (!vcpu->kvm->arch.sgx_provisioning_allowed)
+		return true;
+
+	guest_cpuid = kvm_find_cpuid_entry(vcpu, 0x12, 0);
+	if (!guest_cpuid)
+		return true;
+
+	cpuid_count(0x12, 0, &eax, &ebx, &ecx, &edx);
+	if (guest_cpuid->ebx != ebx || guest_cpuid->edx != edx)
+		return true;
+
+	guest_cpuid = kvm_find_cpuid_entry(vcpu, 0x12, 1);
+	if (!guest_cpuid)
+		return true;
+
+	cpuid_count(0x12, 1, &eax, &ebx, &ecx, &edx);
+	if (guest_cpuid->eax != eax || guest_cpuid->ebx != ebx ||
+	    guest_cpuid->ecx != ecx || guest_cpuid->edx != edx)
+		return true;
+
+	return false;
+}
+
+void vmx_write_encls_bitmap(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
+{
+	/*
+	 * There is no software enable bit for SGX that is virtualized by
+	 * hardware, e.g. there's no CR4.SGXE, so when SGX is disabled in the
+	 * guest (either by the host or by the guest's BIOS) but enabled in the
+	 * host, trap all ENCLS leafs and inject #UD/#GP as needed to emulate
+	 * the expected system behavior for ENCLS.
+	 */
+	u64 bitmap = -1ull;
+
+	/* Nothing to do if hardware doesn't support SGX */
+	if (!cpu_has_vmx_encls_vmexit())
+		return;
+
+	if (guest_cpuid_has(vcpu, X86_FEATURE_SGX) &&
+	    sgx_enabled_in_guest_bios(vcpu)) {
+		if (guest_cpuid_has(vcpu, X86_FEATURE_SGX1)) {
+			bitmap &= ~GENMASK_ULL(ETRACK, ECREATE);
+			if (sgx_intercept_encls_ecreate(vcpu))
+				bitmap |= (1 << ECREATE);
+		}
+
+		if (guest_cpuid_has(vcpu, X86_FEATURE_SGX2))
+			bitmap &= ~GENMASK_ULL(EMODT, EAUG);
+
+		/*
+		 * Trap and execute EINIT if launch control is enabled in the
+		 * host using the guest's values for launch control MSRs, even
+		 * if the guest's values are fixed to hardware default values.
+		 * The MSRs are not loaded/saved on VM-Enter/VM-Exit as writing
+		 * the MSRs is extraordinarily expensive.
+		 */
+		if (boot_cpu_has(X86_FEATURE_SGX_LC))
+			bitmap |= (1 << EINIT);
+
+		if (!vmcs12 && is_guest_mode(vcpu))
+			vmcs12 = get_vmcs12(vcpu);
+		if (vmcs12 && nested_cpu_has_encls_exit(vmcs12))
+			bitmap |= vmcs12->encls_exiting_bitmap;
+	}
+	vmcs_write64(ENCLS_EXITING_BITMAP, bitmap);
+}