Commit 9798adbc authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: VMX: Frame in ENCLS handler for SGX virtualization 



Introduce sgx.c and sgx.h, along with the framework for handling ENCLS
VM-Exits.  Add a bool, enable_sgx, that will eventually be wired up to a
module param to control whether or not SGX virtualization is enabled at
runtime.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarKai Huang <kai.huang@intel.com>
Message-Id: <1c782269608b2f5e1034be450f375a8432fb705d.1618196135.git.kai.huang@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3c0c2ad1

arch/x86/kvm/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ kvm-$(CONFIG_KVM_XEN) += xen.o 


kvm-intel-y		+= vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o \

			   vmx/evmcs.o vmx/nested.o vmx/posted_intr.o

kvm-intel-$(CONFIG_X86_SGX_KVM)	+= vmx/sgx.o



kvm-amd-y		+= svm/svm.o svm/vmenter.o svm/pmu.o svm/nested.o svm/avic.o svm/sev.o



obj-$(CONFIG_KVM)	+= kvm.o

arch/x86/kvm/vmx/sgx.c

0 → 100644
+50 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*  Copyright(c) 2021 Intel Corporation. */



#include <asm/sgx.h>



#include "cpuid.h"

#include "kvm_cache_regs.h"

#include "sgx.h"

#include "vmx.h"

#include "x86.h"



bool __read_mostly enable_sgx;



static inline bool encls_leaf_enabled_in_guest(struct kvm_vcpu *vcpu, u32 leaf)

{

	if (!enable_sgx || !guest_cpuid_has(vcpu, X86_FEATURE_SGX))

		return false;



	if (leaf >= ECREATE && leaf <= ETRACK)

		return guest_cpuid_has(vcpu, X86_FEATURE_SGX1);



	if (leaf >= EAUG && leaf <= EMODT)

		return guest_cpuid_has(vcpu, X86_FEATURE_SGX2);



	return false;

}



static inline bool sgx_enabled_in_guest_bios(struct kvm_vcpu *vcpu)

{

	const u64 bits = FEAT_CTL_SGX_ENABLED | FEAT_CTL_LOCKED;



	return (to_vmx(vcpu)->msr_ia32_feature_control & bits) == bits;

}



int handle_encls(struct kvm_vcpu *vcpu)

{

	u32 leaf = (u32)kvm_rax_read(vcpu);



	if (!encls_leaf_enabled_in_guest(vcpu, leaf)) {

		kvm_queue_exception(vcpu, UD_VECTOR);

	} else if (!sgx_enabled_in_guest_bios(vcpu)) {

		kvm_inject_gp(vcpu, 0);

	} else {

		WARN(1, "KVM: unexpected exit on ENCLS[%u]", leaf);

		vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;

		vcpu->run->hw.hardware_exit_reason = EXIT_REASON_ENCLS;

		return 0;

	}

	return 1;

}

arch/x86/kvm/vmx/sgx.h

0 → 100644
+15 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef __KVM_X86_SGX_H

#define __KVM_X86_SGX_H



#include <linux/kvm_host.h>



#ifdef CONFIG_X86_SGX_KVM

extern bool __read_mostly enable_sgx;



int handle_encls(struct kvm_vcpu *vcpu);

#else

#define enable_sgx 0

#endif



#endif /* __KVM_X86_SGX_H */

arch/x86/kvm/vmx/vmx.c

+6 −3
Original line number Diff line number Diff line
@@ -57,6 +57,7 @@ 
#include "mmu.h"

#include "nested.h"

#include "pmu.h"

#include "sgx.h"

#include "trace.h"

#include "vmcs.h"

#include "vmcs12.h"
@@ -5607,16 +5608,18 @@ static int handle_vmx_instruction(struct kvm_vcpu *vcpu) 
	return 1;

}



#ifndef CONFIG_X86_SGX_KVM

static int handle_encls(struct kvm_vcpu *vcpu)

{

	/*

	 * SGX virtualization is not yet supported.  There is no software

	 * enable bit for SGX, so we have to trap ENCLS and inject a #UD

	 * to prevent the guest from executing ENCLS.

	 * SGX virtualization is disabled.  There is no software enable bit for

	 * SGX, so KVM intercepts all ENCLS leafs and injects a #UD to prevent

	 * the guest from executing ENCLS (when SGX is supported by hardware).

	 */

	kvm_queue_exception(vcpu, UD_VECTOR);

	return 1;

}

#endif /* CONFIG_X86_SGX_KVM */



static int handle_bus_lock_vmexit(struct kvm_vcpu *vcpu)

{