static int handle_ept_violation(struct kvm_vcpu *vcpu)
{
	unsigned long exit_qualification;
	gpa_t gpa;
	u64 error_code;

	exit_qualification = vmx_get_exit_qual(vcpu);

	/*
	 * EPT violation happened while executing iret from NMI,
	 * "blocked by NMI" bit has to be set before next VM entry.
	 * There are errata that may cause this bit to not be set:
	 * AAK134, BY25.
	 */
	if (!(to_vmx(vcpu)->idt_vectoring_info & VECTORING_INFO_VALID_MASK) &&
			enable_vnmi &&
			(exit_qualification & INTR_INFO_UNBLOCK_NMI))
		vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO, GUEST_INTR_STATE_NMI);

	gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS);
	trace_kvm_page_fault(gpa, exit_qualification);

	/* Is it a read fault? */
	error_code = (exit_qualification & EPT_VIOLATION_ACC_READ)
		     ? PFERR_USER_MASK : 0;
	/* Is it a write fault? */
	error_code |= (exit_qualification & EPT_VIOLATION_ACC_WRITE)
		      ? PFERR_WRITE_MASK : 0;
	/* Is it a fetch fault? */
	error_code |= (exit_qualification & EPT_VIOLATION_ACC_INSTR)
		      ? PFERR_FETCH_MASK : 0;
	/* ept page table entry is present? */
	error_code |= (exit_qualification &
		       (EPT_VIOLATION_READABLE | EPT_VIOLATION_WRITABLE |
			EPT_VIOLATION_EXECUTABLE))
		      ? PFERR_PRESENT_MASK : 0;

	error_code |= (exit_qualification & 0x100) != 0 ?
	       PFERR_GUEST_FINAL_MASK : PFERR_GUEST_PAGE_MASK;

	vcpu->arch.exit_qualification = exit_qualification;

	/*
	 * Check that the GPA doesn't exceed physical memory limits, as that is
	 * a guest page fault.  We have to emulate the instruction here, because
	 * if the illegal address is that of a paging structure, then
	 * EPT_VIOLATION_ACC_WRITE bit is set.  Alternatively, if supported we
	 * would also use advanced VM-exit information for EPT violations to
	 * reconstruct the page fault error code.
	 */
	if (unlikely(allow_smaller_maxphyaddr && kvm_vcpu_is_illegal_gpa(vcpu, gpa)))
		return kvm_emulate_instruction(vcpu, 0);

	return kvm_mmu_page_fault(vcpu, gpa, error_code, NULL, 0);
}
Unknown