static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
unsigned nr, bool has_error, u32 error_code,
bool reinject)
{
u32 prev_nr;
int class1, class2;
kvm_make_request(KVM_REQ_EVENT, vcpu);
if (!vcpu->arch.exception.pending) {
queue:
if (has_error && !is_protmode(vcpu))
has_error = false;
vcpu->arch.exception.pending = true;
vcpu->arch.exception.has_error_code = has_error;
vcpu->arch.exception.nr = nr;
vcpu->arch.exception.error_code = error_code;
vcpu->arch.exception.reinject = reinject;
return;
}
/* to check exception */
prev_nr = vcpu->arch.exception.nr;
if (prev_nr == DF_VECTOR) {
/* triple fault -> shutdown */
kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
return;
}
class1 = exception_class(prev_nr);
class2 = exception_class(nr);
if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY)
|| (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) {
/* generate double fault per SDM Table 5-5 */
vcpu->arch.exception.pending = true;
vcpu->arch.exception.has_error_code = true;
vcpu->arch.exception.nr = DF_VECTOR;
vcpu->arch.exception.error_code = 0;
} else
/* replace previous exception with a new one in a hope
that instruction re-execution will regenerate lost
exception */
goto queue;
}
static int
nested_fault(struct vm *vm, int vcpuid, uint64_t info1, uint64_t info2,
uint64_t *retinfo)
{
enum exc_class exc1, exc2;
int type1, vector1;
KASSERT(info1 & VM_INTINFO_VALID, ("info1 %#llx is not valid", info1));
KASSERT(info2 & VM_INTINFO_VALID, ("info2 %#llx is not valid", info2));
/*
* If an exception occurs while attempting to call the double-fault
* handler the processor enters shutdown mode (aka triple fault).
*/
type1 = info1 & VM_INTINFO_TYPE;
vector1 = info1 & 0xff;
if (type1 == VM_INTINFO_HWEXCEPTION && vector1 == IDT_DF) {
VCPU_CTR2(vm, vcpuid, "triple fault: info1(%#llx), info2(%#llx)",
info1, info2);
vm_suspend(vm, VM_SUSPEND_TRIPLEFAULT);
*retinfo = 0;
return (0);
}
/*
* Table 6-5 "Conditions for Generating a Double Fault", Intel SDM, Vol3
*/
exc1 = exception_class(info1);
exc2 = exception_class(info2);
if ((exc1 == EXC_CONTRIBUTORY && exc2 == EXC_CONTRIBUTORY) ||
(exc1 == EXC_PAGEFAULT && exc2 != EXC_BENIGN)) {
/* Convert nested fault into a double fault. */
*retinfo = IDT_DF;
*retinfo |= VM_INTINFO_VALID | VM_INTINFO_HWEXCEPTION;
*retinfo |= VM_INTINFO_DEL_ERRCODE;
} else {
/* Handle exceptions serially */
*retinfo = info2;
}
return (1);
}
