Commit 42cbf068 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: x86: Move #GP injection for VMware into x86_emulate_instruction() 



Immediately inject a #GP when VMware emulation fails and return
EMULATE_DONE instead of propagating EMULATE_FAIL up the stack.  This
helps pave the way for removing EMULATE_FAIL altogether.

Rename EMULTYPE_VMWARE to EMULTYPE_VMWARE_GP to document that the x86
emulator is called to handle VMware #GP interception, e.g. why a #GP
is injected on emulation failure for EMULTYPE_VMWARE_GP.

Drop EMULTYPE_NO_UD_ON_FAIL as a standalone type.  The "no #UD on fail"
is used only in the VMWare case and is obsoleted by having the emulator
itself reinject #GP.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: default avatarLiran Alon <liran.alon@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a6c6ed1e

arch/x86/include/asm/kvm_host.h

+1 −2
Original line number Diff line number Diff line
@@ -1325,8 +1325,7 @@ enum emulation_result { 
#define EMULTYPE_TRAP_UD	    (1 << 1)

#define EMULTYPE_SKIP		    (1 << 2)

#define EMULTYPE_ALLOW_RETRY	    (1 << 3)

#define EMULTYPE_NO_UD_ON_FAIL	    (1 << 4)

#define EMULTYPE_VMWARE		    (1 << 5)

#define EMULTYPE_VMWARE_GP	    (1 << 5)

int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type);

int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,

					void *insn, int insn_len);

arch/x86/kvm/svm.c

+2 −8
Original line number Diff line number Diff line
@@ -2768,7 +2768,6 @@ static int gp_interception(struct vcpu_svm *svm) 
{

	struct kvm_vcpu *vcpu = &svm->vcpu;

	u32 error_code = svm->vmcb->control.exit_info_1;

	int er;



	WARN_ON_ONCE(!enable_vmware_backdoor);
@@ -2780,13 +2779,8 @@ static int gp_interception(struct vcpu_svm *svm) 
		kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);

		return 1;

	}

	er = kvm_emulate_instruction(vcpu,

		EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);

	if (er == EMULATE_USER_EXIT)

		return 0;

	else if (er != EMULATE_DONE)

		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);

	return 1;

	return kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE_GP) !=

						EMULATE_USER_EXIT;

}



static bool is_erratum_383(void)

arch/x86/kvm/vmx/vmx.c

+2 −8
Original line number Diff line number Diff line
@@ -4522,7 +4522,6 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) 
	u32 intr_info, ex_no, error_code;

	unsigned long cr2, rip, dr6;

	u32 vect_info;

	enum emulation_result er;



	vect_info = vmx->idt_vectoring_info;

	intr_info = vmx->exit_intr_info;
@@ -4549,13 +4548,8 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu) 
			kvm_queue_exception_e(vcpu, GP_VECTOR, error_code);

			return 1;

		}

		er = kvm_emulate_instruction(vcpu,

			EMULTYPE_VMWARE | EMULTYPE_NO_UD_ON_FAIL);

		if (er == EMULATE_USER_EXIT)

			return 0;

		else if (er != EMULATE_DONE)

			kvm_queue_exception_e(vcpu, GP_VECTOR, 0);

		return 1;

		return kvm_emulate_instruction(vcpu, EMULTYPE_VMWARE_GP) !=

							EMULATE_USER_EXIT;

	}



	/*

arch/x86/kvm/x86.c

+9 −5
Original line number Diff line number Diff line
@@ -6307,8 +6307,10 @@ static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type) 
	++vcpu->stat.insn_emulation_fail;

	trace_kvm_emulate_insn_failed(vcpu);



	if (emulation_type & EMULTYPE_NO_UD_ON_FAIL)

		return EMULATE_FAIL;

	if (emulation_type & EMULTYPE_VMWARE_GP) {

		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);

		return EMULATE_DONE;

	}



	kvm_queue_exception(vcpu, UD_VECTOR);
@@ -6648,9 +6650,11 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, 
		}

	}



	if ((emulation_type & EMULTYPE_VMWARE) &&

	    !is_vmware_backdoor_opcode(ctxt))

		return EMULATE_FAIL;

	if ((emulation_type & EMULTYPE_VMWARE_GP) &&

	    !is_vmware_backdoor_opcode(ctxt)) {

		kvm_queue_exception_e(vcpu, GP_VECTOR, 0);

		return EMULATE_DONE;

	}



	if (emulation_type & EMULTYPE_SKIP) {

		kvm_rip_write(vcpu, ctxt->_eip);

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