Commit 4d31d9ef authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Pass emulation type to can_emulate_instruction() 



Pass the emulation type to kvm_x86_ops.can_emulate_insutrction() so that
a future commit can harden KVM's SEV support to WARN on emulation
scenarios that should never happen.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Reviewed-by: default avatarLiam Merwick <liam.merwick@oracle.com>
Message-Id: <20220120010719.711476-6-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c532f290

arch/x86/include/asm/kvm_host.h

+2 −1
Original line number Diff line number Diff line
@@ -1482,7 +1482,8 @@ struct kvm_x86_ops { 


	int (*get_msr_feature)(struct kvm_msr_entry *entry);



	bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, void *insn, int insn_len);

	bool (*can_emulate_instruction)(struct kvm_vcpu *vcpu, int emul_type,

					void *insn, int insn_len);



	bool (*apic_init_signal_blocked)(struct kvm_vcpu *vcpu);

	int (*enable_direct_tlbflush)(struct kvm_vcpu *vcpu);

arch/x86/kvm/svm/svm.c

+2 −1
Original line number Diff line number Diff line
@@ -4258,7 +4258,8 @@ static void svm_enable_smi_window(struct kvm_vcpu *vcpu) 
	}

}



static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)

static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,

					void *insn, int insn_len)

{

	bool smep, smap, is_user;

	unsigned long cr4;

arch/x86/kvm/vmx/vmx.c

+4 −3
Original line number Diff line number Diff line
@@ -1487,11 +1487,12 @@ static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data) 
	return 0;

}



static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int insn_len)

static bool vmx_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,

					void *insn, int insn_len)

{

	/*

	 * Emulation of instructions in SGX enclaves is impossible as RIP does

	 * not point  tthe failing instruction, and even if it did, the code

	 * not point at the failing instruction, and even if it did, the code

	 * stream is inaccessible.  Inject #UD instead of exiting to userspace

	 * so that guest userspace can't DoS the guest simply by triggering

	 * emulation (enclaves are CPL3 only).
@@ -5425,7 +5426,7 @@ static int handle_ept_misconfig(struct kvm_vcpu *vcpu) 
{

	gpa_t gpa;



	if (!vmx_can_emulate_instruction(vcpu, NULL, 0))

	if (!vmx_can_emulate_instruction(vcpu, EMULTYPE_PF, NULL, 0))

		return 1;



	/*

arch/x86/kvm/x86.c

+9 −2
Original line number Diff line number Diff line
@@ -6810,6 +6810,13 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val, 
}

EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);



static int kvm_can_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,

				void *insn, int insn_len)

{

	return static_call(kvm_x86_can_emulate_instruction)(vcpu, emul_type,

							    insn, insn_len);

}



int handle_ud(struct kvm_vcpu *vcpu)

{

	static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
@@ -6817,7 +6824,7 @@ int handle_ud(struct kvm_vcpu *vcpu) 
	char sig[5]; /* ud2; .ascii "kvm" */

	struct x86_exception e;



	if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, NULL, 0)))

	if (unlikely(!kvm_can_emulate_insn(vcpu, emul_type, NULL, 0)))

		return 1;



	if (force_emulation_prefix &&
@@ -8193,7 +8200,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, 
	bool writeback = true;

	bool write_fault_to_spt;



	if (unlikely(!static_call(kvm_x86_can_emulate_instruction)(vcpu, insn, insn_len)))

	if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))

		return 1;



	vcpu->arch.l1tf_flush_l1d = true;